From d57b9b518a6f7144c1a9c315347cd52b0f848c15 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Sat, 2 Sep 2023 17:41:55 +0200
Subject: [PATCH 1/8] Introduce `RefasterParameterOrder` check

---
 .../bugpatterns/RefasterParameterOrder.java   | 134 ++++++++++++++++++
 .../refasterrules/AssertJRules.java           |  96 ++++++-------
 .../AssertJThrowingCallableRules.java         |  24 ++--
 .../refasterrules/EqualityRules.java          |   4 +-
 .../refasterrules/ImmutableListRules.java     |   6 +-
 .../refasterrules/JUnitToAssertJRules.java    |  40 +++---
 .../refasterrules/ReactorRules.java           |   6 +-
 .../refasterrules/TestNGToAssertJRules.java   | 112 +++++++--------
 .../RefasterParameterOrderTest.java           | 121 ++++++++++++++++
 9 files changed, 399 insertions(+), 144 deletions(-)
 create mode 100644 error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java
 create mode 100644 error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrderTest.java

diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java
new file mode 100644
index 0000000000..762c6e7e0f
--- /dev/null
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java
@@ -0,0 +1,134 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import static com.google.common.collect.ImmutableList.toImmutableList;
+import static com.google.errorprone.BugPattern.LinkType.CUSTOM;
+import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
+import static com.google.errorprone.BugPattern.StandardTags.STYLE;
+import static com.google.errorprone.matchers.Matchers.anyOf;
+import static com.google.errorprone.matchers.Matchers.hasAnnotation;
+import static java.util.Comparator.comparing;
+import static java.util.stream.Collectors.toCollection;
+import static tech.picnic.errorprone.bugpatterns.util.Documentation.BUG_PATTERNS_BASE_URL;
+
+import com.google.auto.service.AutoService;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Streams;
+import com.google.errorprone.BugPattern;
+import com.google.errorprone.VisitorState;
+import com.google.errorprone.bugpatterns.BugChecker;
+import com.google.errorprone.bugpatterns.BugChecker.ClassTreeMatcher;
+import com.google.errorprone.fixes.SuggestedFix;
+import com.google.errorprone.matchers.Description;
+import com.google.errorprone.matchers.Matcher;
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import com.google.errorprone.util.ASTHelpers;
+import com.sun.source.tree.ClassTree;
+import com.sun.source.tree.IdentifierTree;
+import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.Tree;
+import com.sun.source.tree.VariableTree;
+import com.sun.source.util.TreeScanner;
+import com.sun.tools.javac.code.Symbol;
+import java.util.Comparator;
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Stream;
+import javax.lang.model.element.Name;
+import org.jspecify.annotations.Nullable;
+import tech.picnic.errorprone.bugpatterns.util.SourceCode;
+
+/**
+ * A {@link BugChecker} that flags Refaster methods with a non-canonical parameter order.
+ *
+ * <p>To a first approximation, parameters should be ordered by their first usage in an
+ * {@code @AfterTemplate} method. Ties are broken by preferring the order dictated by methods with a
+ * larger number of parameters.
+ */
+@AutoService(BugChecker.class)
+@BugPattern(
+    summary = "Refaster template parameters should be listed in a canonical order",
+    link = BUG_PATTERNS_BASE_URL + "RefasterParameterOrder",
+    linkType = CUSTOM,
+    severity = SUGGESTION,
+    tags = STYLE)
+public final class RefasterParameterOrder extends BugChecker implements ClassTreeMatcher {
+  private static final long serialVersionUID = 1L;
+  private static final Matcher<Tree> BEFORE_TEMPLATE_METHOD = hasAnnotation(BeforeTemplate.class);
+  private static final Matcher<Tree> BEFORE_OR_AFTER_TEMPLATE_METHOD =
+      anyOf(BEFORE_TEMPLATE_METHOD, hasAnnotation(AfterTemplate.class));
+
+  @Override
+  public Description matchClass(ClassTree tree, VisitorState state) {
+    ImmutableList<MethodTree> methods = getMethodsByPriority(tree, state);
+    if (methods.isEmpty()) {
+      return Description.NO_MATCH;
+    }
+
+    Comparator<VariableTree> canonicalOrder = determineCanonicalParameterOrder(methods);
+
+    return methods.stream()
+        .flatMap(m -> tryReorderParameters(m, canonicalOrder, state))
+        .reduce(SuggestedFix.Builder::merge)
+        .map(SuggestedFix.Builder::build)
+        .map(fix -> describeMatch(tree, fix))
+        .orElse(Description.NO_MATCH);
+  }
+
+  private static ImmutableList<MethodTree> getMethodsByPriority(
+      ClassTree tree, VisitorState state) {
+    return tree.getMembers().stream()
+        .filter(m -> BEFORE_OR_AFTER_TEMPLATE_METHOD.matches(m, state))
+        .map(MethodTree.class::cast)
+        .sorted(
+            comparing((MethodTree m) -> BEFORE_TEMPLATE_METHOD.matches(m, state))
+                .thenComparingInt(m -> -m.getParameters().size()))
+        .collect(toImmutableList());
+  }
+
+  private static Comparator<VariableTree> determineCanonicalParameterOrder(
+      ImmutableList<MethodTree> methods) {
+    Set<Name> canonicalOrder = new LinkedHashSet<>();
+    methods.forEach(m -> processParameters(m, canonicalOrder));
+
+    ImmutableList<Name> reversedCanonicalOrder = ImmutableList.copyOf(canonicalOrder).reverse();
+    return comparing(
+        VariableTree::getName,
+        Comparator.<Name>comparingInt(reversedCanonicalOrder::indexOf)
+            .reversed()
+            .thenComparing(Name::toString));
+  }
+
+  private static void processParameters(MethodTree method, Set<Name> orderedParams) {
+    Set<Symbol> toBeOrdered =
+        method.getParameters().stream()
+            .map(ASTHelpers::getSymbol)
+            .collect(toCollection(HashSet::new));
+
+    new TreeScanner<@Nullable Void, @Nullable Void>() {
+      @Override
+      public @Nullable Void visitIdentifier(IdentifierTree node, @Nullable Void unused) {
+        if (toBeOrdered.remove(ASTHelpers.getSymbol(node))) {
+          orderedParams.add(node.getName());
+        }
+        return super.visitIdentifier(node, null);
+      }
+    }.scan(method, null);
+  }
+
+  private static Stream<SuggestedFix.Builder> tryReorderParameters(
+      MethodTree method, Comparator<VariableTree> canonicalOrder, VisitorState state) {
+    List<? extends VariableTree> originalOrder = method.getParameters();
+    ImmutableList<? extends VariableTree> orderedParams =
+        ImmutableList.sortedCopyOf(canonicalOrder, originalOrder);
+
+    return originalOrder.equals(orderedParams)
+        ? Stream.empty()
+        : Streams.zip(
+            originalOrder.stream(),
+            orderedParams.stream().map(p -> SourceCode.treeToString(p, state)),
+            SuggestedFix.builder()::replace);
+  }
+}
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJRules.java
index 84bac00845..c1b73ecf01 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJRules.java
@@ -530,13 +530,13 @@ MapAssert<K, V> after(Map<K, V> map, K key, V value) {
   static final class AssertThatStreamContainsAnyElementsOf<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).containsAnyElementsOf(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsAnyElementsOf(iterable);
     }
 
@@ -551,13 +551,13 @@ ListAssert<S> after(Stream<S> stream, Iterable<U> iterable) {
   static final class AssertThatStreamContainsAnyOf<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).containsAnyOf(array);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsAnyOf(array);
     }
 
@@ -573,14 +573,14 @@ static final class AssertThatStreamContainsAnyOfVarArgs<S, T extends S, U extend
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsAnyOf" /* Varargs converted to array. */)
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).containsAnyOf(Refaster.asVarargs(elements));
     }
 
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsAnyOf" /* Varargs converted to array. */)
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsAnyOf(Refaster.asVarargs(elements));
     }
 
@@ -596,13 +596,13 @@ ListAssert<S> after(Stream<S> stream, @Repeated U elements) {
   static final class AssertThatStreamContainsAll<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).containsAll(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsAll(iterable);
     }
 
@@ -617,13 +617,13 @@ ListAssert<S> after(Stream<S> stream, Iterable<U> iterable) {
   static final class AssertThatStreamContains<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).contains(array);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).contains(array);
     }
 
@@ -639,14 +639,14 @@ static final class AssertThatStreamContainsVarArgs<S, T extends S, U extends T>
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContains" /* Varargs converted to array. */)
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).contains(Refaster.asVarargs(elements));
     }
 
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContains" /* Varargs converted to array. */)
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).contains(Refaster.asVarargs(elements));
     }
 
@@ -661,7 +661,7 @@ ListAssert<S> after(Stream<S> stream, @Repeated U elements) {
   static final class AssertThatStreamContainsExactlyElementsOf<S, T extends S, U extends T> {
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsExactlyElementsOf(iterable);
     }
 
@@ -676,7 +676,7 @@ ListAssert<S> after(Stream<S> stream, Iterable<U> iterable) {
   static final class AssertThatStreamContainsExactly<S, T extends S, U extends T> {
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsExactly(array);
     }
 
@@ -692,7 +692,7 @@ static final class AssertThatStreamContainsExactlyVarargs<S, T extends S, U exte
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsExactly" /* Varargs converted to array. */)
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsExactly(Refaster.asVarargs(elements));
     }
 
@@ -708,13 +708,13 @@ static final class AssertThatStreamContainsExactlyInAnyOrderElementsOf<
       S, T extends S, U extends T> {
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsExactlyInAnyOrderElementsOf(iterable);
     }
 
     @BeforeTemplate
     AbstractCollectionAssert<?, ?, T, ?> before2(
-        Stream<S> stream, Collector<S, ?, ? extends Multiset<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends Multiset<T>> collector) {
       return assertThat(stream.collect(collector)).containsExactlyInAnyOrderElementsOf(iterable);
     }
 
@@ -729,13 +729,13 @@ ListAssert<S> after(Stream<S> stream, Iterable<U> iterable) {
   static final class AssertThatStreamContainsExactlyInAnyOrder<S, T extends S, U extends T> {
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsExactlyInAnyOrder(array);
     }
 
     @BeforeTemplate
     AbstractCollectionAssert<?, ?, T, ?> before2(
-        Stream<S> stream, Collector<S, ?, ? extends Multiset<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends Multiset<T>> collector) {
       return assertThat(stream.collect(collector)).containsExactlyInAnyOrder(array);
     }
 
@@ -751,7 +751,7 @@ static final class AssertThatStreamContainsExactlyInAnyOrderVarArgs<S, T extends
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsExactlyInAnyOrder" /* Varargs converted to array. */)
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector))
           .containsExactlyInAnyOrder(Refaster.asVarargs(elements));
     }
@@ -759,7 +759,7 @@ ListAssert<T> before(
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsExactlyInAnyOrder" /* Varargs converted to array. */)
     AbstractCollectionAssert<?, ?, T, ?> before2(
-        Stream<S> stream, Collector<S, ?, ? extends Multiset<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends Multiset<T>> collector) {
       return assertThat(stream.collect(collector))
           .containsExactlyInAnyOrder(Refaster.asVarargs(elements));
     }
@@ -776,13 +776,13 @@ ListAssert<S> after(Stream<S> stream, @Repeated U elements) {
   static final class AssertThatStreamContainsSequence<S, T extends S, U extends T> {
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsSequence(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] iterable) {
+        Stream<S> stream, U[] iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsSequence(iterable);
     }
 
@@ -798,7 +798,7 @@ static final class AssertThatStreamContainsSequenceVarArgs<S, T extends S, U ext
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsSequence" /* Varargs converted to array. */)
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsSequence(Refaster.asVarargs(elements));
     }
 
@@ -814,13 +814,13 @@ ListAssert<S> after(Stream<S> stream, @Repeated U elements) {
   static final class AssertThatStreamContainsSubsequence<S, T extends S, U extends T> {
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsSubsequence(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] iterable) {
+        Stream<S> stream, U[] iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsSubsequence(iterable);
     }
 
@@ -836,7 +836,7 @@ static final class AssertThatStreamContainsSubsequenceVarArgs<S, T extends S, U
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsSubsequence" /* Varargs converted to array. */)
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector))
           .containsSubsequence(Refaster.asVarargs(elements));
     }
@@ -853,13 +853,13 @@ ListAssert<S> after(Stream<S> stream, @Repeated U elements) {
   static final class AssertThatStreamDoesNotContainAnyElementsOf<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).doesNotContainAnyElementsOf(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).doesNotContainAnyElementsOf(iterable);
     }
 
@@ -874,13 +874,13 @@ ListAssert<S> after(Stream<S> stream, Iterable<U> iterable) {
   static final class AssertThatStreamDoesNotContain<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).doesNotContain(array);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).doesNotContain(array);
     }
 
@@ -896,14 +896,14 @@ static final class AssertThatStreamDoesNotContainVarArgs<S, T extends S, U exten
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamDoesNotContain" /* Varargs converted to array. */)
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).doesNotContain(Refaster.asVarargs(elements));
     }
 
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamDoesNotContain" /* Varargs converted to array. */)
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).doesNotContain(Refaster.asVarargs(elements));
     }
 
@@ -918,13 +918,13 @@ ListAssert<S> after(Stream<S> stream, @Repeated U elements) {
   static final class AssertThatStreamDoesNotContainSequence<S, T extends S, U extends T> {
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).doesNotContainSequence(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] iterable) {
+        Stream<S> stream, U[] iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).doesNotContainSequence(iterable);
     }
 
@@ -940,7 +940,7 @@ static final class AssertThatStreamDoesNotContainSequenceVarArgs<S, T extends S,
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamDoesNotContainSequence" /* Varargs converted to array. */)
     ListAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector))
           .doesNotContainSequence(Refaster.asVarargs(elements));
     }
@@ -957,13 +957,13 @@ ListAssert<S> after(Stream<S> stream, @Repeated U elements) {
   static final class AssertThatStreamHasSameElementsAs<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).hasSameElementsAs(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).hasSameElementsAs(iterable);
     }
 
@@ -978,13 +978,13 @@ ListAssert<S> after(Stream<S> stream, Iterable<U> iterable) {
   static final class AssertThatStreamContainsOnly<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).containsOnly(array);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] array) {
+        Stream<S> stream, U[] array, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsOnly(array);
     }
 
@@ -1000,14 +1000,14 @@ static final class AssertThatStreamContainsOnlyVarArgs<S, T extends S, U extends
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsOnly" /* Varargs converted to array. */)
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).containsOnly(Refaster.asVarargs(elements));
     }
 
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamContainsOnly" /* Varargs converted to array. */)
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).containsOnly(Refaster.asVarargs(elements));
     }
 
@@ -1022,25 +1022,25 @@ ListAssert<S> after(Stream<S> stream, @Repeated U elements) {
   static final class AssertThatStreamIsSubsetOf<S, T extends S, U extends T> {
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).isSubsetOf(iterable);
     }
 
     @BeforeTemplate
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, U[] iterable) {
+        Stream<S> stream, U[] iterable, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).isSubsetOf(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, Iterable<U> iterable) {
+        Stream<S> stream, Iterable<U> iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).isSubsetOf(iterable);
     }
 
     @BeforeTemplate
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, U[] iterable) {
+        Stream<S> stream, U[] iterable, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).isSubsetOf(iterable);
     }
 
@@ -1056,14 +1056,14 @@ static final class AssertThatStreamIsSubsetOfVarArgs<S, T extends S, U extends T
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamIsSubsetOf" /* Varargs converted to array. */)
     IterableAssert<T> before(
-        Stream<S> stream, Collector<S, ?, ? extends Iterable<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends Iterable<T>> collector) {
       return assertThat(stream.collect(collector)).isSubsetOf(Refaster.asVarargs(elements));
     }
 
     @BeforeTemplate
     @SuppressWarnings("AssertThatStreamIsSubsetOf" /* Varargs converted to array. */)
     ListAssert<T> before2(
-        Stream<S> stream, Collector<S, ?, ? extends List<T>> collector, @Repeated U elements) {
+        Stream<S> stream, @Repeated U elements, Collector<S, ?, ? extends List<T>> collector) {
       return assertThat(stream.collect(collector)).isSubsetOf(Refaster.asVarargs(elements));
     }
 
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJThrowingCallableRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJThrowingCallableRules.java
index 74bd22df35..0a653c520a 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJThrowingCallableRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/AssertJThrowingCallableRules.java
@@ -455,14 +455,14 @@ static final class AssertThatThrownByIOExceptionHasMessageNotContaining {
   static final class AssertThatThrownBy {
     @BeforeTemplate
     AbstractObjectAssert<?, ?> before(
-        Class<? extends Throwable> exceptionType, ThrowingCallable throwingCallable) {
+        ThrowingCallable throwingCallable, Class<? extends Throwable> exceptionType) {
       return assertThatExceptionOfType(exceptionType).isThrownBy(throwingCallable);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     AbstractObjectAssert<?, ?> after(
-        Class<? extends Throwable> exceptionType, ThrowingCallable throwingCallable) {
+        ThrowingCallable throwingCallable, Class<? extends Throwable> exceptionType) {
       return assertThatThrownBy(throwingCallable).isInstanceOf(exceptionType);
     }
   }
@@ -471,8 +471,8 @@ static final class AssertThatThrownByHasMessage {
     @BeforeTemplate
     @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message) {
       return assertThatExceptionOfType(exceptionType)
           .isThrownBy(throwingCallable)
@@ -482,8 +482,8 @@ static final class AssertThatThrownByHasMessage {
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     AbstractObjectAssert<?, ?> after(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message) {
       return assertThatThrownBy(throwingCallable).isInstanceOf(exceptionType).hasMessage(message);
     }
@@ -493,8 +493,8 @@ static final class AssertThatThrownByHasMessageParameters {
     @BeforeTemplate
     @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message,
         @Repeated Object parameters) {
       return assertThatExceptionOfType(exceptionType)
@@ -505,8 +505,8 @@ static final class AssertThatThrownByHasMessageParameters {
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     AbstractObjectAssert<?, ?> after(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message,
         @Repeated Object parameters) {
       return assertThatThrownBy(throwingCallable)
@@ -519,8 +519,8 @@ static final class AssertThatThrownByHasMessageStartingWith {
     @BeforeTemplate
     @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message) {
       return assertThatExceptionOfType(exceptionType)
           .isThrownBy(throwingCallable)
@@ -530,8 +530,8 @@ static final class AssertThatThrownByHasMessageStartingWith {
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     AbstractObjectAssert<?, ?> after(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message) {
       return assertThatThrownBy(throwingCallable)
           .isInstanceOf(exceptionType)
@@ -543,8 +543,8 @@ static final class AssertThatThrownByHasMessageContaining {
     @BeforeTemplate
     @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message) {
       return assertThatExceptionOfType(exceptionType)
           .isThrownBy(throwingCallable)
@@ -554,8 +554,8 @@ static final class AssertThatThrownByHasMessageContaining {
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     AbstractObjectAssert<?, ?> after(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message) {
       return assertThatThrownBy(throwingCallable)
           .isInstanceOf(exceptionType)
@@ -567,8 +567,8 @@ static final class AssertThatThrownByHasMessageNotContaining {
     @BeforeTemplate
     @SuppressWarnings("AssertThatThrownBy" /* This is a more specific template. */)
     AbstractObjectAssert<?, ?> before(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message) {
       return assertThatExceptionOfType(exceptionType)
           .isThrownBy(throwingCallable)
@@ -578,8 +578,8 @@ static final class AssertThatThrownByHasMessageNotContaining {
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
     AbstractObjectAssert<?, ?> after(
-        Class<? extends Throwable> exceptionType,
         ThrowingCallable throwingCallable,
+        Class<? extends Throwable> exceptionType,
         String message) {
       return assertThatThrownBy(throwingCallable)
           .isInstanceOf(exceptionType)
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java
index 119f1634f3..0b30db18b5 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java
@@ -159,12 +159,12 @@ Predicate<T> after() {
   /** Avoid contrived ways of handling {@code null} values during equality testing. */
   static final class EqualsLhsNullable<T, S> {
     @BeforeTemplate
-    boolean before(T value1, S value2) {
+    boolean before(S value2, T value1) {
       return Optional.ofNullable(value1).equals(Optional.of(value2));
     }
 
     @AfterTemplate
-    boolean after(T value1, S value2) {
+    boolean after(S value2, T value1) {
       return value2.equals(value1);
     }
   }
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ImmutableListRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ImmutableListRules.java
index 1848c268b9..aca741d389 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ImmutableListRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ImmutableListRules.java
@@ -118,17 +118,17 @@ ImmutableList<T> after(Collection<T> iterable) {
    */
   static final class ImmutableListSortedCopyOfWithCustomComparator<T> {
     @BeforeTemplate
-    ImmutableList<T> before(Iterable<T> iterable, Comparator<T> cmp) {
+    ImmutableList<T> before(Comparator<T> cmp, Iterable<T> iterable) {
       return Streams.stream(iterable).sorted(cmp).collect(toImmutableList());
     }
 
     @BeforeTemplate
-    ImmutableList<T> before(Collection<T> iterable, Comparator<T> cmp) {
+    ImmutableList<T> before(Comparator<T> cmp, Collection<T> iterable) {
       return iterable.stream().sorted(cmp).collect(toImmutableList());
     }
 
     @AfterTemplate
-    ImmutableList<T> after(Collection<T> iterable, Comparator<? super T> cmp) {
+    ImmutableList<T> after(Comparator<? super T> cmp, Collection<T> iterable) {
       return ImmutableList.sortedCopyOf(cmp, iterable);
     }
   }
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/JUnitToAssertJRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/JUnitToAssertJRules.java
index 2f919e7327..7eeda27c3c 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/JUnitToAssertJRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/JUnitToAssertJRules.java
@@ -276,26 +276,26 @@ void after(Object actual, Object expected) {
 
   static final class AssertThatWithFailMessageStringIsSameAs {
     @BeforeTemplate
-    void before(Object actual, Object expected, String message) {
+    void before(Object actual, String message, Object expected) {
       assertSame(expected, actual, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Object expected, String message) {
+    void after(Object actual, String message, Object expected) {
       assertThat(actual).withFailMessage(message).isSameAs(expected);
     }
   }
 
   static final class AssertThatWithFailMessageSupplierIsSameAs {
     @BeforeTemplate
-    void before(Object actual, Object expected, Supplier<String> supplier) {
+    void before(Object actual, Supplier<String> supplier, Object expected) {
       assertSame(expected, actual, supplier);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Object expected, Supplier<String> supplier) {
+    void after(Object actual, Supplier<String> supplier, Object expected) {
       assertThat(actual).withFailMessage(supplier).isSameAs(expected);
     }
   }
@@ -315,26 +315,26 @@ void after(Object actual, Object expected) {
 
   static final class AssertThatWithFailMessageStringIsNotSameAs {
     @BeforeTemplate
-    void before(Object actual, Object expected, String message) {
+    void before(Object actual, String message, Object expected) {
       assertNotSame(expected, actual, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Object expected, String message) {
+    void after(Object actual, String message, Object expected) {
       assertThat(actual).withFailMessage(message).isNotSameAs(expected);
     }
   }
 
   static final class AssertThatWithFailMessageSupplierIsNotSameAs {
     @BeforeTemplate
-    void before(Object actual, Object expected, Supplier<String> supplier) {
+    void before(Object actual, Supplier<String> supplier, Object expected) {
       assertNotSame(expected, actual, supplier);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Object expected, Supplier<String> supplier) {
+    void after(Object actual, Supplier<String> supplier, Object expected) {
       assertThat(actual).withFailMessage(supplier).isNotSameAs(expected);
     }
   }
@@ -355,13 +355,13 @@ void after(ThrowingCallable throwingCallable, Class<T> clazz) {
   static final class AssertThatThrownByWithFailMessageStringIsExactlyInstanceOf<
       T extends Throwable> {
     @BeforeTemplate
-    void before(Executable throwingCallable, Class<T> clazz, String message) {
+    void before(Executable throwingCallable, String message, Class<T> clazz) {
       assertThrowsExactly(clazz, throwingCallable, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(ThrowingCallable throwingCallable, Class<T> clazz, String message) {
+    void after(ThrowingCallable throwingCallable, String message, Class<T> clazz) {
       assertThatThrownBy(throwingCallable).withFailMessage(message).isExactlyInstanceOf(clazz);
     }
   }
@@ -369,13 +369,13 @@ void after(ThrowingCallable throwingCallable, Class<T> clazz, String message) {
   static final class AssertThatThrownByWithFailMessageSupplierIsExactlyInstanceOf<
       T extends Throwable> {
     @BeforeTemplate
-    void before(Executable throwingCallable, Class<T> clazz, Supplier<String> supplier) {
+    void before(Executable throwingCallable, Supplier<String> supplier, Class<T> clazz) {
       assertThrowsExactly(clazz, throwingCallable, supplier);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(ThrowingCallable throwingCallable, Class<T> clazz, Supplier<String> supplier) {
+    void after(ThrowingCallable throwingCallable, Supplier<String> supplier, Class<T> clazz) {
       assertThatThrownBy(throwingCallable).withFailMessage(supplier).isExactlyInstanceOf(clazz);
     }
   }
@@ -395,26 +395,26 @@ void after(ThrowingCallable throwingCallable, Class<T> clazz) {
 
   static final class AssertThatThrownByWithFailMessageStringIsInstanceOf<T extends Throwable> {
     @BeforeTemplate
-    void before(Executable throwingCallable, Class<T> clazz, String message) {
+    void before(Executable throwingCallable, String message, Class<T> clazz) {
       assertThrows(clazz, throwingCallable, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(ThrowingCallable throwingCallable, Class<T> clazz, String message) {
+    void after(ThrowingCallable throwingCallable, String message, Class<T> clazz) {
       assertThatThrownBy(throwingCallable).withFailMessage(message).isInstanceOf(clazz);
     }
   }
 
   static final class AssertThatThrownByWithFailMessageSupplierIsInstanceOf<T extends Throwable> {
     @BeforeTemplate
-    void before(Executable throwingCallable, Class<T> clazz, Supplier<String> supplier) {
+    void before(Executable throwingCallable, Supplier<String> supplier, Class<T> clazz) {
       assertThrows(clazz, throwingCallable, supplier);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(ThrowingCallable throwingCallable, Class<T> clazz, Supplier<String> supplier) {
+    void after(ThrowingCallable throwingCallable, Supplier<String> supplier, Class<T> clazz) {
       assertThatThrownBy(throwingCallable).withFailMessage(supplier).isInstanceOf(clazz);
     }
   }
@@ -488,26 +488,26 @@ void after(Object actual, Class<T> clazz) {
 
   static final class AssertThatWithFailMessageStringIsInstanceOf<T> {
     @BeforeTemplate
-    void before(Object actual, Class<T> clazz, String message) {
+    void before(Object actual, String message, Class<T> clazz) {
       assertInstanceOf(clazz, actual, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Class<T> clazz, String message) {
+    void after(Object actual, String message, Class<T> clazz) {
       assertThat(actual).withFailMessage(message).isInstanceOf(clazz);
     }
   }
 
   static final class AssertThatWithFailMessageSupplierIsInstanceOf<T> {
     @BeforeTemplate
-    void before(Object actual, Class<T> clazz, Supplier<String> supplier) {
+    void before(Object actual, Supplier<String> supplier, Class<T> clazz) {
       assertInstanceOf(clazz, actual, supplier);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Class<T> clazz, Supplier<String> supplier) {
+    void after(Object actual, Supplier<String> supplier, Class<T> clazz) {
       assertThat(actual).withFailMessage(supplier).isInstanceOf(clazz);
     }
   }
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
index 977248a2d8..959a9085b8 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
@@ -727,7 +727,7 @@ abstract static class FluxMap<T, S> {
     abstract S transformation(@MayOptionallyUse T value);
 
     @BeforeTemplate
-    Flux<S> before(Flux<T> flux, boolean delayUntilEnd, int maxConcurrency, int prefetch) {
+    Flux<S> before(Flux<T> flux, int prefetch, boolean delayUntilEnd, int maxConcurrency) {
       return Refaster.anyOf(
           flux.concatMap(x -> Mono.just(transformation(x))),
           flux.concatMap(x -> Flux.just(transformation(x))),
@@ -795,7 +795,7 @@ abstract static class FluxMapNotNull<T, S> {
 
     @BeforeTemplate
     @SuppressWarnings("java:S138" /* Method is long, but not complex. */)
-    Publisher<S> before(Flux<T> flux, boolean delayUntilEnd, int maxConcurrency, int prefetch) {
+    Publisher<S> before(Flux<T> flux, int prefetch, boolean delayUntilEnd, int maxConcurrency) {
       return Refaster.anyOf(
           flux.concatMap(
               x ->
@@ -1669,7 +1669,7 @@ StepVerifier.Step<T> after(StepVerifier.Step<T> step, T object) {
   // a `@Matches(DoesNotDropElements.class)` or `@NotMatches(MayDropElements.class)` guard.
   static final class FluxAsStepVerifierExpectNext<T, L extends List<T>> {
     @BeforeTemplate
-    StepVerifier.Step<L> before(Flux<T> flux, Collector<? super T, ?, L> listCollector, T object) {
+    StepVerifier.Step<L> before(Flux<T> flux, T object, Collector<? super T, ?, L> listCollector) {
       return flux.collect(listCollector)
           .as(StepVerifier::create)
           .assertNext(list -> assertThat(list).containsExactly(object));
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/TestNGToAssertJRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/TestNGToAssertJRules.java
index 8c9521ca3a..89b0973563 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/TestNGToAssertJRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/TestNGToAssertJRules.java
@@ -237,13 +237,13 @@ void after(Object actual, Object expected) {
 
   static final class AssertSameWithMessage {
     @BeforeTemplate
-    void before(Object actual, Object expected, String message) {
+    void before(Object actual, String message, Object expected) {
       assertSame(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Object expected, String message) {
+    void after(Object actual, String message, Object expected) {
       assertThat(actual).withFailMessage(message).isSameAs(expected);
     }
   }
@@ -263,13 +263,13 @@ void after(Object actual, Object expected) {
 
   static final class AssertNotSameWithMessage {
     @BeforeTemplate
-    void before(Object actual, Object expected, String message) {
+    void before(Object actual, String message, Object expected) {
       assertNotSame(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Object expected, String message) {
+    void after(Object actual, String message, Object expected) {
       assertThat(actual).withFailMessage(message).isNotSameAs(expected);
     }
   }
@@ -339,63 +339,63 @@ void after(Object actual, Object expected) {
 
   static final class AssertEqualWithMessage {
     @BeforeTemplate
-    void before(boolean actual, boolean expected, String message) {
+    void before(boolean actual, String message, boolean expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(byte actual, byte expected, String message) {
+    void before(byte actual, String message, byte expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(char actual, char expected, String message) {
+    void before(char actual, String message, char expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(short actual, short expected, String message) {
+    void before(short actual, String message, short expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(int actual, int expected, String message) {
+    void before(int actual, String message, int expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(long actual, long expected, String message) {
+    void before(long actual, String message, long expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(float actual, float expected, String message) {
+    void before(float actual, String message, float expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(double actual, double expected, String message) {
+    void before(double actual, String message, double expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(Object actual, Object expected, String message) {
+    void before(Object actual, String message, Object expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(String actual, String expected, String message) {
+    void before(String actual, String message, String expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(Map<?, ?> actual, Map<?, ?> expected, String message) {
+    void before(Map<?, ?> actual, String message, Map<?, ?> expected) {
       assertEquals(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Object expected, String message) {
+    void after(Object actual, String message, Object expected) {
       assertThat(actual).withFailMessage(message).isEqualTo(expected);
     }
   }
@@ -415,13 +415,13 @@ void after(float actual, float expected, float delta) {
 
   static final class AssertEqualFloatsWithDeltaWithMessage {
     @BeforeTemplate
-    void before(float actual, float expected, float delta, String message) {
+    void before(float actual, String message, float expected, float delta) {
       assertEquals(actual, expected, delta, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(float actual, float expected, float delta, String message) {
+    void after(float actual, String message, float expected, float delta) {
       assertThat(actual).withFailMessage(message).isCloseTo(expected, offset(delta));
     }
   }
@@ -441,13 +441,13 @@ void after(double actual, double expected, double delta) {
 
   static final class AssertEqualDoublesWithDeltaWithMessage {
     @BeforeTemplate
-    void before(double actual, double expected, double delta, String message) {
+    void before(double actual, String message, double expected, double delta) {
       assertEquals(actual, expected, delta, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(double actual, double expected, double delta, String message) {
+    void after(double actual, String message, double expected, double delta) {
       assertThat(actual).withFailMessage(message).isCloseTo(expected, offset(delta));
     }
   }
@@ -507,53 +507,53 @@ void after(Object[] actual, Object[] expected) {
 
   static final class AssertEqualArrayIterationOrderWithMessage {
     @BeforeTemplate
-    void before(boolean[] actual, boolean[] expected, String message) {
+    void before(boolean[] actual, String message, boolean[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(byte[] actual, byte[] expected, String message) {
+    void before(byte[] actual, String message, byte[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(char[] actual, char[] expected, String message) {
+    void before(char[] actual, String message, char[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(short[] actual, short[] expected, String message) {
+    void before(short[] actual, String message, short[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(int[] actual, int[] expected, String message) {
+    void before(int[] actual, String message, int[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(long[] actual, long[] expected, String message) {
+    void before(long[] actual, String message, long[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(float[] actual, float[] expected, String message) {
+    void before(float[] actual, String message, float[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(double[] actual, double[] expected, String message) {
+    void before(double[] actual, String message, double[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(Object[] actual, Object[] expected, String message) {
+    void before(Object[] actual, String message, Object[] expected) {
       assertEquals(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object[] actual, Object[] expected, String message) {
+    void after(Object[] actual, String message, Object[] expected) {
       assertThat(actual).withFailMessage(message).containsExactly(expected);
     }
   }
@@ -573,13 +573,13 @@ void after(Object[] actual, Object[] expected) {
 
   static final class AssertEqualArraysIrrespectiveOfOrderWithMessage {
     @BeforeTemplate
-    void before(Object[] actual, Object[] expected, String message) {
+    void before(Object[] actual, String message, Object[] expected) {
       assertEqualsNoOrder(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object[] actual, Object[] expected, String message) {
+    void after(Object[] actual, String message, Object[] expected) {
       assertThat(actual).withFailMessage(message).containsExactlyInAnyOrder(expected);
     }
   }
@@ -601,13 +601,13 @@ <S, T extends S> void after(Iterator<S> actual, Iterator<T> expected) {
 
   static final class AssertEqualIteratorIterationOrderWithMessage {
     @BeforeTemplate
-    void before(Iterator<?> actual, Iterator<?> expected, String message) {
+    void before(Iterator<?> actual, String message, Iterator<?> expected) {
       assertEquals(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    <S, T extends S> void after(Iterator<S> actual, Iterator<T> expected, String message) {
+    <S, T extends S> void after(Iterator<S> actual, String message, Iterator<T> expected) {
       // XXX: This is not `null`-safe.
       // XXX: The `ImmutableList.copyOf` should actually *not* be imported statically.
       assertThat(actual)
@@ -639,18 +639,18 @@ <S, T extends S> void after(Iterable<S> actual, Iterable<T> expected) {
 
   static final class AssertEqualIterableIterationOrderWithMessage {
     @BeforeTemplate
-    void before(Iterable<?> actual, Iterable<?> expected, String message) {
+    void before(Iterable<?> actual, String message, Iterable<?> expected) {
       assertEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(Collection<?> actual, Collection<?> expected, String message) {
+    void before(Collection<?> actual, String message, Collection<?> expected) {
       assertEquals(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    <S, T extends S> void after(Iterable<S> actual, Iterable<T> expected, String message) {
+    <S, T extends S> void after(Iterable<S> actual, String message, Iterable<T> expected) {
       assertThat(actual).withFailMessage(message).containsExactlyElementsOf(expected);
     }
   }
@@ -670,13 +670,13 @@ <S, T extends S> void after(Set<S> actual, Set<T> expected) {
 
   static final class AssertEqualSetsWithMessage {
     @BeforeTemplate
-    void before(Set<?> actual, Set<?> expected, String message) {
+    void before(Set<?> actual, String message, Set<?> expected) {
       assertEquals(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    <S, T extends S> void after(Set<S> actual, Set<T> expected, String message) {
+    <S, T extends S> void after(Set<S> actual, String message, Set<T> expected) {
       assertThat(actual).withFailMessage(message).hasSameElementsAs(expected);
     }
   }
@@ -751,68 +751,68 @@ void after(Object actual, Object expected) {
 
   static final class AssertUnequalWithMessage {
     @BeforeTemplate
-    void before(boolean actual, boolean expected, String message) {
+    void before(boolean actual, String message, boolean expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(byte actual, byte expected, String message) {
+    void before(byte actual, String message, byte expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(char actual, char expected, String message) {
+    void before(char actual, String message, char expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(short actual, short expected, String message) {
+    void before(short actual, String message, short expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(int actual, int expected, String message) {
+    void before(int actual, String message, int expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(long actual, long expected, String message) {
+    void before(long actual, String message, long expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(float actual, float expected, String message) {
+    void before(float actual, String message, float expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(double actual, double expected, String message) {
+    void before(double actual, String message, double expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(Object actual, Object expected, String message) {
+    void before(Object actual, String message, Object expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(String actual, String expected, String message) {
+    void before(String actual, String message, String expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(Set<?> actual, Set<?> expected, String message) {
+    void before(Set<?> actual, String message, Set<?> expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @BeforeTemplate
-    void before(Map<?, ?> actual, Map<?, ?> expected, String message) {
+    void before(Map<?, ?> actual, String message, Map<?, ?> expected) {
       assertNotEquals(actual, expected, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(Object actual, Object expected, String message) {
+    void after(Object actual, String message, Object expected) {
       assertThat(actual).withFailMessage(message).isNotEqualTo(expected);
     }
   }
@@ -832,13 +832,13 @@ void after(float actual, float expected, float delta) {
 
   static final class AssertUnequalFloatsWithDeltaWithMessage {
     @BeforeTemplate
-    void before(float actual, float expected, float delta, String message) {
+    void before(float actual, String message, float expected, float delta) {
       assertNotEquals(actual, expected, delta, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(float actual, float expected, float delta, String message) {
+    void after(float actual, String message, float expected, float delta) {
       assertThat(actual).withFailMessage(message).isNotCloseTo(expected, offset(delta));
     }
   }
@@ -858,13 +858,13 @@ void after(double actual, double expected, double delta) {
 
   static final class AssertUnequalDoublesWithDeltaWithMessage {
     @BeforeTemplate
-    void before(double actual, double expected, double delta, String message) {
+    void before(double actual, String message, double expected, double delta) {
       assertNotEquals(actual, expected, delta, message);
     }
 
     @AfterTemplate
     @UseImportPolicy(STATIC_IMPORT_ALWAYS)
-    void after(double actual, double expected, double delta, String message) {
+    void after(double actual, String message, double expected, double delta) {
       assertThat(actual).withFailMessage(message).isNotCloseTo(expected, offset(delta));
     }
   }
diff --git a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrderTest.java b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrderTest.java
new file mode 100644
index 0000000000..b8e1f82be3
--- /dev/null
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrderTest.java
@@ -0,0 +1,121 @@
+package tech.picnic.errorprone.bugpatterns;
+
+import com.google.errorprone.BugCheckerRefactoringTestHelper;
+import com.google.errorprone.BugCheckerRefactoringTestHelper.TestMode;
+import com.google.errorprone.CompilationTestHelper;
+import org.junit.jupiter.api.Test;
+
+final class RefasterParameterOrderTest {
+  @Test
+  void identification() {
+    CompilationTestHelper.newInstance(RefasterParameterOrder.class, getClass())
+        .addSourceLines(
+            "A.java",
+            "import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;",
+            "import static org.assertj.core.api.Assertions.assertThat;",
+            "",
+            "import com.google.errorprone.refaster.annotation.AfterTemplate;",
+            "import com.google.errorprone.refaster.annotation.BeforeTemplate;",
+            "import com.google.errorprone.refaster.annotation.Placeholder;",
+            "import com.google.errorprone.refaster.annotation.UseImportPolicy;",
+            "import java.util.Map;",
+            "",
+            "class A {",
+            "  class UnusedLexicographicallyOrderedParameters {",
+            "    @BeforeTemplate",
+            "    void singleParam(int a) {}",
+            "",
+            "    @BeforeTemplate",
+            "    void twoParams(int a, int b) {}",
+            "",
+            "    @Placeholder",
+            "    void notATemplateMethod(int b, int a) {}",
+            "  }",
+            "",
+            "  class NonParameterValueIdentifierIsIgnored<K, V> {",
+            "    @AfterTemplate",
+            "    @UseImportPolicy(value = STATIC_IMPORT_ALWAYS)",
+            "    void after(Map<K, V> map, V value) {",
+            "      assertThat(map).containsValue(value);",
+            "    }",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  void replacement() {
+    BugCheckerRefactoringTestHelper.newInstance(RefasterParameterOrder.class, getClass())
+        .addInputLines(
+            "A.java",
+            "import com.google.errorprone.refaster.annotation.AfterTemplate;",
+            "import com.google.errorprone.refaster.annotation.BeforeTemplate;",
+            "",
+            "class A {",
+            "  class UnusedUnsortedParameters {",
+            "    @BeforeTemplate",
+            "    void before(int b, int a) {}",
+            "  }",
+            "",
+            "  class UnsortedParametersWithoutAfterTemplate {",
+            "    @BeforeTemplate",
+            "    int before(int a, int b, int c, int d) {",
+            "      return b + a + d + b + c;",
+            "    }",
+            "  }",
+            "",
+            "  class UnsortedParametersWithMultipleMethodsAndParameterCounts {",
+            "    @BeforeTemplate",
+            "    int before(int b, int a, int g, int f, int d) {",
+            "      return f + a + g + b + d;",
+            "    }",
+            "",
+            "    @AfterTemplate",
+            "    int after(int a, int b) {",
+            "      return b + a;",
+            "    }",
+            "",
+            "    @AfterTemplate",
+            "    int after2(int a, int d, int f) {",
+            "      return d + a + f;",
+            "    }",
+            "  }",
+            "}")
+        .addOutputLines(
+            "A.java",
+            "import com.google.errorprone.refaster.annotation.AfterTemplate;",
+            "import com.google.errorprone.refaster.annotation.BeforeTemplate;",
+            "",
+            "class A {",
+            "  class UnusedUnsortedParameters {",
+            "    @BeforeTemplate",
+            "    void before(int a, int b) {}",
+            "  }",
+            "",
+            "  class UnsortedParametersWithoutAfterTemplate {",
+            "    @BeforeTemplate",
+            "    int before(int b, int a, int d, int c) {",
+            "      return b + a + d + b + c;",
+            "    }",
+            "  }",
+            "",
+            "  class UnsortedParametersWithMultipleMethodsAndParameterCounts {",
+            "    @BeforeTemplate",
+            "    int before(int d, int a, int f, int b, int g) {",
+            "      return f + a + g + b + d;",
+            "    }",
+            "",
+            "    @AfterTemplate",
+            "    int after(int a, int b) {",
+            "      return b + a;",
+            "    }",
+            "",
+            "    @AfterTemplate",
+            "    int after2(int d, int a, int f) {",
+            "      return d + a + f;",
+            "    }",
+            "  }",
+            "}")
+        .doTest(TestMode.TEXT_MATCH);
+  }
+}

From 2050fedfd0175128fc86224024ec355a842902c6 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Sat, 2 Sep 2023 18:23:42 +0200
Subject: [PATCH 2/8] Fix build, simplify some rules

---
 .../bugpatterns/RefasterParameterOrder.java   |  3 +++
 .../refasterrules/EqualityRules.java          | 22 +++++--------------
 .../refasterrules/EqualityRulesTestInput.java | 13 +++++------
 .../EqualityRulesTestOutput.java              | 10 +++------
 4 files changed, 18 insertions(+), 30 deletions(-)

diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java
index 762c6e7e0f..16e2578740 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java
@@ -60,6 +60,9 @@ public final class RefasterParameterOrder extends BugChecker implements ClassTre
   private static final Matcher<Tree> BEFORE_OR_AFTER_TEMPLATE_METHOD =
       anyOf(BEFORE_TEMPLATE_METHOD, hasAnnotation(AfterTemplate.class));
 
+  /** Instantiates a new {@link RefasterParameterOrder} instance. */
+  public RefasterParameterOrder() {}
+
   @Override
   public Description matchClass(ClassTree tree, VisitorState state) {
     ImmutableList<MethodTree> methods = getMethodsByPriority(tree, state);
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java
index 0b30db18b5..e47918d4bc 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java
@@ -157,23 +157,13 @@ Predicate<T> after() {
   }
 
   /** Avoid contrived ways of handling {@code null} values during equality testing. */
-  static final class EqualsLhsNullable<T, S> {
-    @BeforeTemplate
-    boolean before(S value2, T value1) {
-      return Optional.ofNullable(value1).equals(Optional.of(value2));
-    }
-
-    @AfterTemplate
-    boolean after(S value2, T value1) {
-      return value2.equals(value1);
-    }
-  }
-
-  /** Avoid contrived ways of handling {@code null} values during equality testing. */
-  static final class EqualsRhsNullable<T, S> {
+  static final class Equals<T, S> {
     @BeforeTemplate
     boolean before(T value1, S value2) {
-      return Optional.of(value1).equals(Optional.ofNullable(value2));
+      return Refaster.anyOf(
+          Optional.of(value1).equals(Optional.of(value2)),
+          Optional.of(value1).equals(Optional.ofNullable(value2)),
+          Optional.ofNullable(value2).equals(Optional.of(value1)));
     }
 
     @AfterTemplate
@@ -183,7 +173,7 @@ boolean after(T value1, S value2) {
   }
 
   /** Avoid contrived ways of handling {@code null} values during equality testing. */
-  static final class EqualsLhsAndRhsNullable<T, S> {
+  static final class ObjectsEquals<T, S> {
     @BeforeTemplate
     boolean before(T value1, S value2) {
       return Optional.ofNullable(value1).equals(Optional.ofNullable(value2));
diff --git a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestInput.java b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestInput.java
index 93b9764079..016580a647 100644
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestInput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestInput.java
@@ -69,15 +69,14 @@ Predicate<String> testPredicateLambda() {
     return not(v -> v.isEmpty());
   }
 
-  boolean testEqualsLhsNullable() {
-    return Optional.ofNullable("foo").equals(Optional.of("bar"));
-  }
-
-  boolean testEqualsRhsNullable() {
-    return Optional.of("foo").equals(Optional.ofNullable("bar"));
+  ImmutableSet<Boolean> testEquals() {
+    return ImmutableSet.of(
+        Optional.of("foo").equals(Optional.of("bar")),
+        Optional.of("baz").equals(Optional.ofNullable("qux")),
+        Optional.ofNullable("quux").equals(Optional.of("quuz")));
   }
 
-  boolean testEqualsLhsAndRhsNullable() {
+  boolean testObjectsEquals() {
     return Optional.ofNullable("foo").equals(Optional.ofNullable("bar"));
   }
 }
diff --git a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestOutput.java b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestOutput.java
index c61eb76748..39bab876fa 100644
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestOutput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestOutput.java
@@ -69,15 +69,11 @@ Predicate<String> testPredicateLambda() {
     return v -> !v.isEmpty();
   }
 
-  boolean testEqualsLhsNullable() {
-    return "bar".equals("foo");
+  ImmutableSet<Boolean> testEquals() {
+    return ImmutableSet.of("foo".equals("bar"), "baz".equals("qux"), "quuz".equals("quux"));
   }
 
-  boolean testEqualsRhsNullable() {
-    return "foo".equals("bar");
-  }
-
-  boolean testEqualsLhsAndRhsNullable() {
+  boolean testObjectsEquals() {
     return Objects.equals("foo", "bar");
   }
 }

From 6c857d6388fa16febd7007c1b9ea3b556b24b16b Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Sat, 2 Sep 2023 18:46:39 +0200
Subject: [PATCH 3/8] Rename check

---
 ...ameterOrder.java => RefasterMethodParameterOrder.java} | 8 ++++----
 ...derTest.java => RefasterMethodParameterOrderTest.java} | 6 +++---
 2 files changed, 7 insertions(+), 7 deletions(-)
 rename error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/{RefasterParameterOrder.java => RefasterMethodParameterOrder.java} (95%)
 rename error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/{RefasterParameterOrderTest.java => RefasterMethodParameterOrderTest.java} (94%)

diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrder.java
similarity index 95%
rename from error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java
rename to error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrder.java
index 16e2578740..ff92688bf8 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrder.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrder.java
@@ -50,18 +50,18 @@
 @AutoService(BugChecker.class)
 @BugPattern(
     summary = "Refaster template parameters should be listed in a canonical order",
-    link = BUG_PATTERNS_BASE_URL + "RefasterParameterOrder",
+    link = BUG_PATTERNS_BASE_URL + "RefasterMethodParameterOrder",
     linkType = CUSTOM,
     severity = SUGGESTION,
     tags = STYLE)
-public final class RefasterParameterOrder extends BugChecker implements ClassTreeMatcher {
+public final class RefasterMethodParameterOrder extends BugChecker implements ClassTreeMatcher {
   private static final long serialVersionUID = 1L;
   private static final Matcher<Tree> BEFORE_TEMPLATE_METHOD = hasAnnotation(BeforeTemplate.class);
   private static final Matcher<Tree> BEFORE_OR_AFTER_TEMPLATE_METHOD =
       anyOf(BEFORE_TEMPLATE_METHOD, hasAnnotation(AfterTemplate.class));
 
-  /** Instantiates a new {@link RefasterParameterOrder} instance. */
-  public RefasterParameterOrder() {}
+  /** Instantiates a new {@link RefasterMethodParameterOrder} instance. */
+  public RefasterMethodParameterOrder() {}
 
   @Override
   public Description matchClass(ClassTree tree, VisitorState state) {
diff --git a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrderTest.java b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
similarity index 94%
rename from error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrderTest.java
rename to error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
index b8e1f82be3..d0d5aa1b3c 100644
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterParameterOrderTest.java
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
@@ -5,10 +5,10 @@
 import com.google.errorprone.CompilationTestHelper;
 import org.junit.jupiter.api.Test;
 
-final class RefasterParameterOrderTest {
+final class RefasterMethodParameterOrderTest {
   @Test
   void identification() {
-    CompilationTestHelper.newInstance(RefasterParameterOrder.class, getClass())
+    CompilationTestHelper.newInstance(RefasterMethodParameterOrder.class, getClass())
         .addSourceLines(
             "A.java",
             "import static com.google.errorprone.refaster.ImportPolicy.STATIC_IMPORT_ALWAYS;",
@@ -45,7 +45,7 @@ void identification() {
 
   @Test
   void replacement() {
-    BugCheckerRefactoringTestHelper.newInstance(RefasterParameterOrder.class, getClass())
+    BugCheckerRefactoringTestHelper.newInstance(RefasterMethodParameterOrder.class, getClass())
         .addInputLines(
             "A.java",
             "import com.google.errorprone.refaster.annotation.AfterTemplate;",

From 474f36e487dcb5351181330e53cec1da0ad5f372 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Sun, 8 Oct 2023 15:21:56 +0200
Subject: [PATCH 4/8] Post-rebase fix

---
 .../bugpatterns/RefasterMethodParameterOrder.java  |  2 ++
 .../errorprone/refasterrules/ReactorRules.java     | 14 +++++++-------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrder.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrder.java
index ff92688bf8..46575300b3 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrder.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrder.java
@@ -47,6 +47,8 @@
  * {@code @AfterTemplate} method. Ties are broken by preferring the order dictated by methods with a
  * larger number of parameters.
  */
+// XXX: This check can introduce suggestions that are incompatible with Error Prone's
+// `InconsistentOverloads` check. Review whether/how to improve this.
 @AutoService(BugChecker.class)
 @BugPattern(
     summary = "Refaster template parameters should be listed in a canonical order",
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
index 959a9085b8..927adb4217 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
@@ -437,10 +437,12 @@ Flux<T> after(Flux<T> flux, T object) {
   static final class FluxEmpty<T, S extends Comparable<? super S>> {
     @BeforeTemplate
     Flux<T> before(
-        int prefetch,
         Function<? super Object[], ? extends T> combinator,
+        int prefetch,
         Comparator<? super T> comparator) {
       return Refaster.anyOf(
+          Flux.zip(combinator),
+          Flux.zip(combinator, prefetch),
           Flux.concat(),
           Flux.concatDelayError(),
           Flux.firstWithSignal(),
@@ -456,13 +458,11 @@ Flux<T> before(
           Flux.mergePriorityDelayError(prefetch, comparator),
           Flux.mergeSequential(),
           Flux.mergeSequential(prefetch),
-          Flux.mergeSequentialDelayError(prefetch),
-          Flux.zip(combinator),
-          Flux.zip(combinator, prefetch));
+          Flux.mergeSequentialDelayError(prefetch));
     }
 
     @BeforeTemplate
-    Flux<T> before(int prefetch, Function<Object[], T> combinator) {
+    Flux<T> before(Function<Object[], T> combinator, int prefetch) {
       return Refaster.anyOf(
           Flux.combineLatest(combinator), Flux.combineLatest(combinator, prefetch));
     }
@@ -1125,9 +1125,9 @@ Flux<T> before(
         Function<? super S, P> function,
         @Matches(IsIdentityOperation.class)
             Function<? super P, ? extends Publisher<? extends T>> identityOperation,
+        int prefetch,
         boolean delayUntilEnd,
-        int maxConcurrency,
-        int prefetch) {
+        int maxConcurrency) {
       return Refaster.anyOf(
           mono.map(function).flatMapMany(identityOperation),
           mono.flux().concatMap(function),

From 4e9bff6455d979bf0f22e787f131c66b7cf1fb21 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Wed, 10 Jan 2024 20:03:02 +0100
Subject: [PATCH 5/8] Work around `rewrite-templating` limitation

---
 .../bugpatterns/RefasterMethodParameterOrderTest.java  | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
index d0d5aa1b3c..501d1840ed 100644
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
@@ -45,9 +45,13 @@ void identification() {
 
   @Test
   void replacement() {
+    // XXX: Drop the package declaration once OpenRewrite properly handles Refaster rules in the
+    // unnamed package.
     BugCheckerRefactoringTestHelper.newInstance(RefasterMethodParameterOrder.class, getClass())
         .addInputLines(
-            "A.java",
+            "pkg/A.java",
+            "package pkg;",
+            "",
             "import com.google.errorprone.refaster.annotation.AfterTemplate;",
             "import com.google.errorprone.refaster.annotation.BeforeTemplate;",
             "",
@@ -82,7 +86,9 @@ void replacement() {
             "  }",
             "}")
         .addOutputLines(
-            "A.java",
+            "pkg/A.java",
+            "package pkg;",
+            "",
             "import com.google.errorprone.refaster.annotation.AfterTemplate;",
             "import com.google.errorprone.refaster.annotation.BeforeTemplate;",
             "",

From 95b2c6eabf07d0ec74b0fa377456a708f08a76e5 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Wed, 10 Jan 2024 22:30:22 +0100
Subject: [PATCH 6/8] Link PR

---
 .../bugpatterns/RefasterMethodParameterOrderTest.java           | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
index 501d1840ed..c6beec5997 100644
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
@@ -46,7 +46,7 @@ void identification() {
   @Test
   void replacement() {
     // XXX: Drop the package declaration once OpenRewrite properly handles Refaster rules in the
-    // unnamed package.
+    // unnamed package. See https://github.com/openrewrite/rewrite-templating/pull/64.
     BugCheckerRefactoringTestHelper.newInstance(RefasterMethodParameterOrder.class, getClass())
         .addInputLines(
             "pkg/A.java",

From d6690cfc8d72a5d1b1b84070f8dabd8ab27c0931 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Wed, 10 Jan 2024 22:40:12 +0100
Subject: [PATCH 7/8] Address PR feedback

---
 .../bugpatterns/RefasterMethodParameterOrderTest.java    | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
index c6beec5997..b16a5ed6a1 100644
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
@@ -39,6 +39,15 @@ void identification() {
             "      assertThat(map).containsValue(value);",
             "    }",
             "  }",
+            "",
+            "  // BUG: Diagnostic contains:",
+            "  class UnusedLexicographicallyUnorderedParameters {",
+            "    @BeforeTemplate",
+            "    void foo(int a, int b) {}",
+            "",
+            "    @BeforeTemplate",
+            "    void bar(int b, int a) {}",
+            "  }",
             "}")
         .doTest();
   }

From 4984efaf25618cacda24464e9b0d4d9f49639a70 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Thu, 11 Jan 2024 07:35:06 +0100
Subject: [PATCH 8/8] Drop workaround

---
 .../bugpatterns/RefasterMethodParameterOrderTest.java  | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
index b16a5ed6a1..6ac21f65ab 100644
--- a/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
+++ b/error-prone-contrib/src/test/java/tech/picnic/errorprone/bugpatterns/RefasterMethodParameterOrderTest.java
@@ -54,13 +54,9 @@ void identification() {
 
   @Test
   void replacement() {
-    // XXX: Drop the package declaration once OpenRewrite properly handles Refaster rules in the
-    // unnamed package. See https://github.com/openrewrite/rewrite-templating/pull/64.
     BugCheckerRefactoringTestHelper.newInstance(RefasterMethodParameterOrder.class, getClass())
         .addInputLines(
-            "pkg/A.java",
-            "package pkg;",
-            "",
+            "A.java",
             "import com.google.errorprone.refaster.annotation.AfterTemplate;",
             "import com.google.errorprone.refaster.annotation.BeforeTemplate;",
             "",
@@ -95,9 +91,7 @@ void replacement() {
             "  }",
             "}")
         .addOutputLines(
-            "pkg/A.java",
-            "package pkg;",
-            "",
+            "A.java",
             "import com.google.errorprone.refaster.annotation.AfterTemplate;",
             "import com.google.errorprone.refaster.annotation.BeforeTemplate;",
             "",