diff --git a/build-logic/build-parameters/build.gradle.kts b/build-logic/build-parameters/build.gradle.kts
index 8ae8c48961..43e35e4023 100644
--- a/build-logic/build-parameters/build.gradle.kts
+++ b/build-logic/build-parameters/build.gradle.kts
@@ -49,4 +49,8 @@ buildParameters {
         defaultValue.set(true)
         description.set("Fail build on javadoc warnings")
     }
+    bool("skipErrorProne") {
+        defaultValue.set(false)
+        description.set("Skip Error Prone verifications")
+    }
 }
diff --git a/build-logic/code-quality/build.gradle.kts b/build-logic/code-quality/build.gradle.kts
index 7441054169..9fba6ad0f3 100644
--- a/build-logic/code-quality/build.gradle.kts
+++ b/build-logic/code-quality/build.gradle.kts
@@ -7,4 +7,5 @@ dependencies {
     api(projects.basics)
     api("org.sonarqube:org.sonarqube.gradle.plugin:4.4.1.3373")
     api("com.github.autostyle:autostyle-plugin-gradle:4.0")
+    api("net.ltgt.gradle:gradle-errorprone-plugin:3.1.0")
 }
diff --git a/build-logic/code-quality/src/main/kotlin/testng.errorprone.gradle.kts b/build-logic/code-quality/src/main/kotlin/testng.errorprone.gradle.kts
new file mode 100644
index 0000000000..6b8ad6908a
--- /dev/null
+++ b/build-logic/code-quality/src/main/kotlin/testng.errorprone.gradle.kts
@@ -0,0 +1,14 @@
+import net.ltgt.gradle.errorprone.errorprone
+
+plugins {
+    id("net.ltgt.errorprone")
+    id("build-logic.build-params")
+}
+
+dependencies {
+    errorprone("com.google.errorprone:error_prone_core:2.20.0")
+}
+
+tasks.withType<JavaCompile>().configureEach {
+    options.errorprone.disableWarningsInGeneratedCode.set(true)
+}
diff --git a/build-logic/jvm/src/main/kotlin/testng.java.gradle.kts b/build-logic/jvm/src/main/kotlin/testng.java.gradle.kts
index 677df7d681..361ad11b4a 100644
--- a/build-logic/jvm/src/main/kotlin/testng.java.gradle.kts
+++ b/build-logic/jvm/src/main/kotlin/testng.java.gradle.kts
@@ -42,3 +42,7 @@ tasks.configureEach<Test> {
     inputs.property("java.vm.version", System.getProperty("java.vm.version"))
     inputs.property("java.vm.vendor", System.getProperty("java.vm.vendor"))
 }
+
+if (!buildParameters.skipErrorProne) {
+    apply(plugin = "testng.errorprone")
+}
diff --git a/testng-asserts/src/test/java/org/testng/AssertTest.java b/testng-asserts/src/test/java/org/testng/AssertTest.java
index dff81b4b91..9034a5a504 100644
--- a/testng-asserts/src/test/java/org/testng/AssertTest.java
+++ b/testng-asserts/src/test/java/org/testng/AssertTest.java
@@ -305,22 +305,10 @@ public void compareUnEqualDoubleArraysWithDelta() {
     Assert.assertEquals(actual, expected, 0.1d);
   }
 
-  @SuppressWarnings("serial")
   @Test(expectedExceptions = AssertionError.class)
   public void assertEqualsMapShouldFail() {
-    Map<String, String> mapActual =
-        new HashMap<String, String>() {
-          {
-            put("a", "1");
-          }
-        };
-    Map<String, String> mapExpected =
-        new HashMap<String, String>() {
-          {
-            put("a", "1");
-            put("b", "2");
-          }
-        };
+    Map<String, String> mapActual = Map.of("a", "1");
+    Map<String, String> mapExpected = Map.of("a", "1", "b", "2");
 
     Assert.assertEquals(mapActual, mapExpected);
   }
@@ -654,6 +642,11 @@ static class BrokenEqualsTrue {
     public boolean equals(Object o) {
       return true; // broken implementation
     }
+
+    @Override
+    public int hashCode() {
+      return 0;
+    }
   }
 
   static class BrokenEqualsFalse {
@@ -661,5 +654,10 @@ static class BrokenEqualsFalse {
     public boolean equals(Object o) {
       return false; // broken implementation
     }
+
+    @Override
+    public int hashCode() {
+      return 0;
+    }
   }
 }
diff --git a/testng-core/src/main/java/org/testng/SuiteResult.java b/testng-core/src/main/java/org/testng/SuiteResult.java
index 982978e077..d10a300262 100644
--- a/testng-core/src/main/java/org/testng/SuiteResult.java
+++ b/testng-core/src/main/java/org/testng/SuiteResult.java
@@ -6,7 +6,7 @@
 import org.testng.xml.XmlSuite;
 
 /** This class logs the result of an entire Test Suite (defined by a property file). */
-class SuiteResult implements ISuiteResult, Comparable<ISuiteResult> {
+class SuiteResult implements ISuiteResult, Comparable<SuiteResult> {
   private final XmlSuite m_suite;
   private final ITestContext m_testContext;
 
@@ -26,7 +26,7 @@ public XmlSuite getSuite() {
   }
 
   @Override
-  public int compareTo(@Nonnull ISuiteResult other) {
+  public int compareTo(@Nonnull SuiteResult other) {
     int result = 0;
     try {
       String n1 = getTestContext().getName();
diff --git a/testng-core/src/main/java/org/testng/internal/ClonedMethod.java b/testng-core/src/main/java/org/testng/internal/ClonedMethod.java
index a72c48e665..55830f3d54 100644
--- a/testng-core/src/main/java/org/testng/internal/ClonedMethod.java
+++ b/testng-core/src/main/java/org/testng/internal/ClonedMethod.java
@@ -138,7 +138,7 @@ public boolean hasMoreInvocation() {
 
   @Override
   public Class<?> getRealClass() {
-    return m_javaMethod.getClass();
+    return m_javaMethod.getDeclaringClass();
   }
 
   @Override
diff --git a/testng-core/src/main/java/org/testng/internal/Graph.java b/testng-core/src/main/java/org/testng/internal/Graph.java
index 7be39f3dc7..a50ec5cdc5 100644
--- a/testng-core/src/main/java/org/testng/internal/Graph.java
+++ b/testng-core/src/main/java/org/testng/internal/Graph.java
@@ -1,9 +1,11 @@
 package org.testng.internal;
 
+import java.util.ArrayDeque;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Comparator;
+import java.util.Deque;
 import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -190,9 +192,9 @@ public List<T> findPredecessors(T o) {
     // already encountered.  "queue" is the queue of items whose
     // predecessors we haven't yet explored.
 
-    LinkedList<T> result = new LinkedList<>();
+    Deque<T> result = new ArrayDeque<>();
     Set<T> visited = new HashSet<>();
-    LinkedList<T> queue = new LinkedList<>();
+    Deque<T> queue = new ArrayDeque<>();
     visited.add(o);
     queue.addLast(o);
 
@@ -206,7 +208,7 @@ public List<T> findPredecessors(T o) {
       }
     }
 
-    return result;
+    return new ArrayList<>(result);
   }
 
   @Override
diff --git a/testng-core/src/main/java/org/testng/internal/Tarjan.java b/testng-core/src/main/java/org/testng/internal/Tarjan.java
index 2880746f50..1111be0f55 100644
--- a/testng-core/src/main/java/org/testng/internal/Tarjan.java
+++ b/testng-core/src/main/java/org/testng/internal/Tarjan.java
@@ -1,9 +1,9 @@
 package org.testng.internal;
 
+import java.util.ArrayDeque;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Stack;
 import org.testng.collections.Lists;
 import org.testng.collections.Maps;
 
@@ -14,13 +14,13 @@
  */
 public class Tarjan<T> {
   int m_index = 0;
-  private final Stack<T> stack;
+  private final ArrayDeque<T> stack;
   Map<T, Integer> visitedNodes = Maps.newHashMap();
   Map<T, Integer> m_lowlinks = Maps.newHashMap();
   private List<T> m_cycle;
 
   public Tarjan(Graph<T> graph, T start) {
-    stack = new Stack<>();
+    stack = new ArrayDeque<>();
     run(graph, start);
   }
 
diff --git a/testng-core/src/main/java/org/testng/internal/annotations/JDK15TagFactory.java b/testng-core/src/main/java/org/testng/internal/annotations/JDK15TagFactory.java
index 37d603e291..000180101d 100644
--- a/testng-core/src/main/java/org/testng/internal/annotations/JDK15TagFactory.java
+++ b/testng-core/src/main/java/org/testng/internal/annotations/JDK15TagFactory.java
@@ -644,7 +644,7 @@ private Object invokeMethod(Annotation test, String methodName) {
     Object result = null;
     try {
       // Note:  we should cache methods already looked up
-      Method m = test.getClass().getMethod(methodName);
+      Method m = test.annotationType().getMethod(methodName);
       result = m.invoke(test);
     } catch (Exception e) {
       Logger.getLogger(JDK15TagFactory.class).error(e.getMessage(), e);
diff --git a/testng-core/src/test/java/NoPackageTest.java b/testng-core/src/test/java/NoPackageTest.java
index d5185ce5a9..f7f8cf2455 100644
--- a/testng-core/src/test/java/NoPackageTest.java
+++ b/testng-core/src/test/java/NoPackageTest.java
@@ -1,3 +1,5 @@
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.AfterMethod;
 import org.testng.annotations.Test;
 
@@ -12,6 +14,6 @@ public void test() {
 
   @AfterMethod(groups = {"nopackage"})
   public void after() {
-    assert m_run : "test method was not run";
+    assertTrue(m_run, "test method was not run");
   }
 }
diff --git a/testng-core/src/test/java/test/ClassConfigurations.java b/testng-core/src/test/java/test/ClassConfigurations.java
index 144710f14a..bfe477267c 100644
--- a/testng-core/src/test/java/test/ClassConfigurations.java
+++ b/testng-core/src/test/java/test/ClassConfigurations.java
@@ -1,5 +1,7 @@
 package test;
 
+import static org.testng.Assert.assertEquals;
+
 import org.testng.annotations.AfterTest;
 import org.testng.annotations.BeforeClass;
 import org.testng.annotations.Test;
@@ -29,22 +31,19 @@ public void afterTestClass() {
 
   @Test
   public void testOne() {
-    //    System.out.println("testOne");
-    assert beforeCount == 1;
-    assert afterCount == 0;
+    assertEquals(beforeCount, 1);
+    assertEquals(afterCount, 0);
   }
 
   @Test
   public void testTwo() {
-    //    System.out.println("testTwo");
-    assert beforeCount == 1;
-    assert afterCount == 0;
+    assertEquals(beforeCount, 1);
+    assertEquals(afterCount, 0);
   }
 
   @Test
   public void testThree() {
-    //    System.out.println("testThree");
-    assert beforeCount == 1;
-    assert afterCount == 0;
+    assertEquals(beforeCount, 1);
+    assertEquals(afterCount, 0);
   }
 }
diff --git a/testng-core/src/test/java/test/CtorCalledOnce.java b/testng-core/src/test/java/test/CtorCalledOnce.java
index eeb4aa381d..2df5bd6f07 100644
--- a/testng-core/src/test/java/test/CtorCalledOnce.java
+++ b/testng-core/src/test/java/test/CtorCalledOnce.java
@@ -1,5 +1,7 @@
 package test;
 
+import static org.testng.Assert.assertEquals;
+
 import org.testng.annotations.AfterTest;
 import org.testng.annotations.Test;
 
@@ -16,17 +18,17 @@ public CtorCalledOnce() {
 
   @Test
   public void testMethod1() {
-    assert instantiated == 1 : "Expected 1, was invoked " + instantiated + " times";
+    assertEquals(instantiated, 1, "Expected 1, was invoked " + instantiated + " times");
   }
 
   @Test
   public void testMethod2() {
-    assert instantiated == 1 : "Expected 1, was invoked " + instantiated + " times";
+    assertEquals(instantiated, 1, "Expected 1, was invoked " + instantiated + " times");
   }
 
   @Test
   public void testMethod3() {
-    assert instantiated == 1 : "Expected 1, was invoked " + instantiated + " times";
+    assertEquals(instantiated, 1, "Expected 1, was invoked " + instantiated + " times");
   }
 
   @AfterTest
diff --git a/testng-core/src/test/java/test/Exclude.java b/testng-core/src/test/java/test/Exclude.java
index cbbe0f18a4..23fafd1364 100644
--- a/testng-core/src/test/java/test/Exclude.java
+++ b/testng-core/src/test/java/test/Exclude.java
@@ -1,5 +1,7 @@
 package test;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.Test;
 
 public class Exclude {
@@ -32,14 +34,15 @@ public void excluded2() {
       dependsOnGroups = {"group1"},
       groups = {"group2"})
   public void verify() {
-    assert m_included1 && m_included2 && m_excluded1 && m_excluded2
-        : "Should all be true: "
+    assertTrue(
+        m_included1 && m_included2 && m_excluded1 && m_excluded2,
+        "Should all be true: "
             + m_included1
             + " "
             + m_included2
             + " "
             + m_excluded1
             + " "
-            + m_excluded2;
+            + m_excluded2);
   }
 }
diff --git a/testng-core/src/test/java/test/MethodTest.java b/testng-core/src/test/java/test/MethodTest.java
index 10effb2a40..dbd261068e 100644
--- a/testng-core/src/test/java/test/MethodTest.java
+++ b/testng-core/src/test/java/test/MethodTest.java
@@ -1,5 +1,7 @@
 package test;
 
+import static org.testng.AssertJUnit.assertEquals;
+
 import org.testng.Assert;
 import org.testng.annotations.Test;
 import test.sample.Sample2;
@@ -36,7 +38,7 @@ public void excludeMethodsOnly() {
   @Test
   public void excludePackage() {
     addClass(CLASS_NAME);
-    assert 1 == getTest().getXmlClasses().size();
+    assertEquals(getTest().getXmlClasses().size(), 1);
     addExcludedMethod(CLASS_NAME, ".*");
     run();
     String[] passed = {};
diff --git a/testng-core/src/test/java/test/NestedStaticTest.java b/testng-core/src/test/java/test/NestedStaticTest.java
index 02ef058501..1d2870bdc0 100644
--- a/testng-core/src/test/java/test/NestedStaticTest.java
+++ b/testng-core/src/test/java/test/NestedStaticTest.java
@@ -1,6 +1,5 @@
 package test;
 
-import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import org.testng.Assert;
@@ -19,13 +18,7 @@ public void nestedClassShouldBeIncluded() {
     tng.addListener(tla);
     tng.run();
 
-    Set<String> expected =
-        new HashSet<String>() {
-          {
-            add("nested");
-            add("f");
-          }
-        };
+    Set<String> expected = Set.of("nested", "f");
     Set<String> actual = Sets.newHashSet();
     List<ITestResult> passedTests = tla.getPassedTests();
     for (ITestResult t : passedTests) {
diff --git a/testng-core/src/test/java/test/SampleInheritance.java b/testng-core/src/test/java/test/SampleInheritance.java
index 31e2ba6581..139980f69f 100644
--- a/testng-core/src/test/java/test/SampleInheritance.java
+++ b/testng-core/src/test/java/test/SampleInheritance.java
@@ -1,5 +1,8 @@
 package test;
 
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.BeforeClass;
 import org.testng.annotations.Test;
 import test.sample.BaseSampleInheritance;
@@ -17,9 +20,9 @@ public void configuration0() {
       groups = "final",
       dependsOnGroups = {"configuration1"})
   public void configuration2() {
-    assert m_configurations.size() == 2 : "Expected size 2 found " + m_configurations.size();
-    assert "configuration0".equals(m_configurations.get(0)) : "Expected configuration0 to be run";
-    assert "configuration1".equals(m_configurations.get(1)) : "Expected configuration1 to be run";
+    assertEquals(m_configurations.size(), 2, "Expected size 2 found " + m_configurations.size());
+    assertEquals(m_configurations.get(0), "configuration0", "Expected configuration0 to be run");
+    assertEquals(m_configurations.get(1), "configuration1", "Expected configuration1 to be run");
     addConfiguration("configuration2");
   }
 
@@ -27,15 +30,15 @@ public void configuration2() {
       groups = "final",
       dependsOnGroups = {"inheritedTestMethod"})
   public void inheritedMethodsWereCalledInOrder() {
-    assert m_invokedBaseMethod : "Didn't invoke test method in base class";
-    assert m_invokedBaseConfiguration : "Didn't invoke configuration method in base class";
+    assertTrue(m_invokedBaseMethod, "Didn't invoke test method in base class");
+    assertTrue(m_invokedBaseConfiguration, "Didn't invoke configuration method in base class");
   }
 
   @Test(groups = "final2", dependsOnGroups = "final")
   public void configurationsWereCalledInOrder() {
-    assert m_configurations.size() == 3;
-    assert "configuration0".equals(m_configurations.get(0)) : "Expected configuration0 to be run";
-    assert "configuration1".equals(m_configurations.get(1)) : "Expected configuration1 to be run";
-    assert "configuration2".equals(m_configurations.get(2)) : "Expected configuration1 to be run";
+    assertEquals(m_configurations.size(), 3);
+    assertEquals(m_configurations.get(0), "configuration0", "Expected configuration0 to be run");
+    assertEquals(m_configurations.get(1), "configuration1", "Expected configuration1 to be run");
+    assertEquals(m_configurations.get(2), "configuration2", "Expected configuration1 to be run");
   }
 }
diff --git a/testng-core/src/test/java/test/classgroup/Second.java b/testng-core/src/test/java/test/classgroup/Second.java
index 78f11af8ab..a6ffa31f58 100644
--- a/testng-core/src/test/java/test/classgroup/Second.java
+++ b/testng-core/src/test/java/test/classgroup/Second.java
@@ -1,5 +1,7 @@
 package test.classgroup;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.Test;
 
 @Test(dependsOnGroups = {"first"})
@@ -7,6 +9,6 @@ public class Second {
 
   @Test
   public void verify() {
-    assert First.allRun() : "Methods for class First should have been invoked first.";
+    assertTrue(First.allRun(), "Methods for class First should have been invoked first.");
   }
 }
diff --git a/testng-core/src/test/java/test/configuration/issue2729/BeforeConfigTestSample.java b/testng-core/src/test/java/test/configuration/issue2729/BeforeConfigTestSample.java
index ad73df8199..ee232b6554 100644
--- a/testng-core/src/test/java/test/configuration/issue2729/BeforeConfigTestSample.java
+++ b/testng-core/src/test/java/test/configuration/issue2729/BeforeConfigTestSample.java
@@ -9,6 +9,7 @@
 public class BeforeConfigTestSample {
   @BeforeClass
   public void beforeClass() {
+    @SuppressWarnings("ConstantOverflow")
     int i = 5 / 0;
   }
 
diff --git a/testng-core/src/test/java/test/custom/CustomAttributesTransformer.java b/testng-core/src/test/java/test/custom/CustomAttributesTransformer.java
index 831ba5d875..8f5e45071c 100644
--- a/testng-core/src/test/java/test/custom/CustomAttributesTransformer.java
+++ b/testng-core/src/test/java/test/custom/CustomAttributesTransformer.java
@@ -3,6 +3,8 @@
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
+import java.util.Arrays;
+import java.util.Objects;
 import org.testng.IAnnotationTransformer;
 import org.testng.annotations.CustomAttribute;
 import org.testng.annotations.ITestAnnotation;
@@ -41,5 +43,20 @@ public String[] values() {
     public Class<? extends Annotation> annotationType() {
       return CustomAttribute.class;
     }
+
+    @Override
+    public boolean equals(Object o) {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+      MoreAttribute that = (MoreAttribute) o;
+      return Objects.equals(key, that.key) && Arrays.equals(values, that.values);
+    }
+
+    @Override
+    public int hashCode() {
+      int result = Objects.hash(key);
+      result = 31 * result + Arrays.hashCode(values);
+      return result;
+    }
   }
 }
diff --git a/testng-core/src/test/java/test/dataprovider/issue2327/TestClassSample.java b/testng-core/src/test/java/test/dataprovider/issue2327/TestClassSample.java
index bc4d643bb0..11e778f1f3 100644
--- a/testng-core/src/test/java/test/dataprovider/issue2327/TestClassSample.java
+++ b/testng-core/src/test/java/test/dataprovider/issue2327/TestClassSample.java
@@ -1,8 +1,9 @@
 package test.dataprovider.issue2327;
 
 import java.lang.reflect.Method;
+import java.util.ArrayList;
 import java.util.Iterator;
-import java.util.LinkedList;
+import java.util.List;
 import org.testng.annotations.BeforeMethod;
 import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
@@ -16,7 +17,7 @@ public void setup(Method method, Object[] params) {
 
   @DataProvider(name = "dp", parallel = true)
   public Iterator<Object> dp() {
-    LinkedList<Object> objects = new LinkedList<>();
+    List<Object> objects = new ArrayList<>();
     objects.add("Dataset1");
     objects.add("Dataset2");
     return objects.iterator();
diff --git a/testng-core/src/test/java/test/dataprovider/issue2565/SampleTestUsingFunction.java b/testng-core/src/test/java/test/dataprovider/issue2565/SampleTestUsingFunction.java
index 4da351119c..834a4384f2 100644
--- a/testng-core/src/test/java/test/dataprovider/issue2565/SampleTestUsingFunction.java
+++ b/testng-core/src/test/java/test/dataprovider/issue2565/SampleTestUsingFunction.java
@@ -12,7 +12,7 @@ public class SampleTestUsingFunction {
 
   @Test(dataProvider = "dp")
   public void testMethod(Function<String, String> data) {
-    data.apply("Bumble_Bee");
+    String ignored = data.apply("Bumble_Bee");
   }
 
   @DataProvider(name = "dp")
diff --git a/testng-core/src/test/java/test/dataprovider/issue2565/SampleTestUsingPredicate.java b/testng-core/src/test/java/test/dataprovider/issue2565/SampleTestUsingPredicate.java
index 2311414d87..7315b10fe1 100644
--- a/testng-core/src/test/java/test/dataprovider/issue2565/SampleTestUsingPredicate.java
+++ b/testng-core/src/test/java/test/dataprovider/issue2565/SampleTestUsingPredicate.java
@@ -11,7 +11,7 @@ public class SampleTestUsingPredicate {
 
   @Test(dataProvider = "dp")
   public void testMethod(Predicate<String> data) {
-    data.test("IronHide");
+    boolean ignored = data.test("IronHide");
   }
 
   @DataProvider(name = "dp")
diff --git a/testng-core/src/test/java/test/dependent/BaseOrderMethodTest.java b/testng-core/src/test/java/test/dependent/BaseOrderMethodTest.java
index 235f41ec93..d3b86b5b37 100644
--- a/testng-core/src/test/java/test/dependent/BaseOrderMethodTest.java
+++ b/testng-core/src/test/java/test/dependent/BaseOrderMethodTest.java
@@ -1,5 +1,7 @@
 package test.dependent;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.Test;
 
 /**
@@ -30,13 +32,14 @@ public void third0() {
 
   protected void verifyGroup(int groupNumber, boolean[] group) {
     for (int i = 0; i < group.length; i++) {
-      assert group[i]
-          : "Error while running group "
+      assertTrue(
+          group[i],
+          "Error while running group "
               + groupNumber
               + ": "
               + " index "
               + i
-              + " of previous group should have been run before.";
+              + " of previous group should have been run before.");
     }
   }
 }
diff --git a/testng-core/src/test/java/test/dependent/SampleDependentConfigurationMethods.java b/testng-core/src/test/java/test/dependent/SampleDependentConfigurationMethods.java
index a90c7e5d53..2855f952d7 100644
--- a/testng-core/src/test/java/test/dependent/SampleDependentConfigurationMethods.java
+++ b/testng-core/src/test/java/test/dependent/SampleDependentConfigurationMethods.java
@@ -1,5 +1,7 @@
 package test.dependent;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.BeforeMethod;
 import org.testng.annotations.Test;
 
@@ -14,13 +16,13 @@ public void createInstance() {
 
   @BeforeMethod(dependsOnMethods = {"createInstance"})
   public void firstInvocation() {
-    assert m_create : "createInstance() was never called";
+    assertTrue(m_create, "createInstance() was never called");
     m_first = true;
   }
 
   @Test
   public void verifyDependents() {
-    assert m_create : "createInstance() was never called";
-    assert m_first : "firstInvocation() was never called";
+    assertTrue(m_create, "createInstance() was never called");
+    assertTrue(m_first, "firstInvocation() was never called");
   }
 }
diff --git a/testng-core/src/test/java/test/dependent/SampleDependentMethods.java b/testng-core/src/test/java/test/dependent/SampleDependentMethods.java
index 24fb3c3bab..f0754a020a 100644
--- a/testng-core/src/test/java/test/dependent/SampleDependentMethods.java
+++ b/testng-core/src/test/java/test/dependent/SampleDependentMethods.java
@@ -1,5 +1,8 @@
 package test.dependent;
 
+import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.AfterClass;
 import org.testng.annotations.Test;
 
@@ -16,7 +19,7 @@ public class SampleDependentMethods {
 
   @Test
   public void oneA() {
-    assert !m_secondA : "secondA shouldn't have been run yet";
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
     m_oneA = true;
   }
 
@@ -25,32 +28,32 @@ public void canBeRunAnytime() {}
 
   @Test(dependsOnMethods = {"oneA", "oneB"})
   public void secondA() {
-    assert m_oneA : "oneA wasn't run";
-    assert m_oneB : "oneB wasn't run";
-    assert !m_secondA : "secondA shouldn't have been run yet";
+    assertTrue(m_oneA, "oneA wasn't run");
+    assertTrue(m_oneB, "oneB wasn't run");
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
     m_secondA = true;
   }
 
   @Test(dependsOnMethods = {"secondA"})
   public void thirdA() {
-    assert m_oneA : "oneA wasn't run";
-    assert m_oneB : "oneB wasn't run";
-    assert m_secondA : "secondA wasn't run";
-    assert !m_thirdA : "thirdA shouldn't have been run yet";
+    assertTrue(m_oneA, "oneA wasn't run");
+    assertTrue(m_oneB, "oneB wasn't run");
+    assertTrue(m_secondA, "secondA wasn't run");
+    assertFalse(m_thirdA, "thirdA shouldn't have been run yet");
     m_thirdA = true;
   }
 
   @Test
   public void oneB() {
-    assert !m_secondA : "secondA shouldn't have been run yet";
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
     m_oneB = true;
   }
 
   @AfterClass
   public void tearDown() {
-    assert m_oneA : "oneA wasn't run";
-    assert m_oneB : "oneB wasn't run";
-    assert m_secondA : "secondA wasn't run";
-    assert m_thirdA : "thirdA wasn't run";
+    assertTrue(m_oneA, "oneA wasn't run");
+    assertTrue(m_oneB, "oneB wasn't run");
+    assertTrue(m_secondA, "secondA wasn't run");
+    assertTrue(m_thirdA, "thirdA wasn't run");
   }
 }
diff --git a/testng-core/src/test/java/test/dependent/SampleDependentMethods2.java b/testng-core/src/test/java/test/dependent/SampleDependentMethods2.java
index 709e356fbc..5cfaafc215 100644
--- a/testng-core/src/test/java/test/dependent/SampleDependentMethods2.java
+++ b/testng-core/src/test/java/test/dependent/SampleDependentMethods2.java
@@ -1,5 +1,8 @@
 package test.dependent;
 
+import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.AfterClass;
 import org.testng.annotations.Test;
 
@@ -16,7 +19,7 @@ public class SampleDependentMethods2 {
 
   @Test(groups = {"one"})
   public void oneA() {
-    assert !m_secondA : "secondA shouldn't have been run yet";
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
     m_oneA = true;
   }
 
@@ -25,32 +28,32 @@ public void canBeRunAnytime() {}
 
   @Test(dependsOnGroups = {"one"})
   public void secondA() {
-    assert m_oneA : "oneA wasn't run";
-    assert m_oneB : "oneB wasn't run";
-    assert !m_secondA : "secondA shouldn't have been run yet";
+    assertTrue(m_oneA, "oneA wasn't run");
+    assertTrue(m_oneB, "oneB wasn't run");
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
     m_secondA = true;
   }
 
   @Test(dependsOnMethods = {"secondA"})
   public void thirdA() {
-    assert m_oneA : "oneA wasn't run";
-    assert m_oneB : "oneB wasn't run";
-    assert m_secondA : "secondA wasn't run";
-    assert !m_thirdA : "thirdA shouldn't have been run yet";
+    assertTrue(m_oneA, "oneA wasn't run");
+    assertTrue(m_oneB, "oneB wasn't run");
+    assertTrue(m_secondA, "secondA wasn't run");
+    assertFalse(m_thirdA, "thirdA shouldn't have been run yet");
     m_thirdA = true;
   }
 
   @Test(groups = {"one"})
   public void oneB() {
-    assert !m_secondA : "secondA shouldn't have been run yet";
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
     m_oneB = true;
   }
 
   @AfterClass
   public void tearDown() {
-    assert m_oneA : "oneA wasn't run";
-    assert m_oneB : "oneB wasn't run";
-    assert m_secondA : "secondA wasn't run";
-    assert m_thirdA : "thirdA wasn't run";
+    assertTrue(m_oneA, "oneA wasn't run");
+    assertTrue(m_oneB, "oneB wasn't run");
+    assertTrue(m_secondA, "secondA wasn't run");
+    assertTrue(m_thirdA, "thirdA wasn't run");
   }
 }
diff --git a/testng-core/src/test/java/test/dependent/SampleDependentMethods3.java b/testng-core/src/test/java/test/dependent/SampleDependentMethods3.java
index 5c023827cd..3f141a1e08 100644
--- a/testng-core/src/test/java/test/dependent/SampleDependentMethods3.java
+++ b/testng-core/src/test/java/test/dependent/SampleDependentMethods3.java
@@ -1,5 +1,9 @@
 package test.dependent;
 
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.AfterClass;
 import org.testng.annotations.Parameters;
 import org.testng.annotations.Test;
@@ -16,30 +20,30 @@ public class SampleDependentMethods3 {
 
   @Test
   public void one() {
-    assert !m_secondA : "secondA shouldn't have been run yet";
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
     m_oneA = true;
   }
 
   @Parameters({"foo"})
   @Test
   public void one(String s) {
-    assert !m_secondA : "secondA shouldn't have been run yet";
-    assert "Cedric".equals(s) : "Expected parameter value Cedric but got " + s;
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
+    assertEquals(s, "Cedric", "Expected parameter value Cedric but got " + s);
     m_oneB = true;
   }
 
   @Test(dependsOnMethods = {"one"})
   public void secondA() {
-    assert m_oneA : "oneA wasn't run";
-    assert m_oneB : "oneB wasn't run";
-    assert !m_secondA : "secondA shouldn't have been run yet";
+    assertTrue(m_oneA, "oneA wasn't run");
+    assertTrue(m_oneB, "oneB wasn't run");
+    assertFalse(m_secondA, "secondA shouldn't have been run yet");
     m_secondA = true;
   }
 
   @AfterClass
   public void tearDown() {
-    assert m_oneA : "oneA wasn't run";
-    assert m_oneB : "oneB wasn't run";
-    assert m_secondA : "secondA wasn't run";
+    assertTrue(m_oneA, "oneA wasn't run");
+    assertTrue(m_oneB, "oneB wasn't run");
+    assertTrue(m_secondA, "secondA wasn't run");
   }
 }
diff --git a/testng-core/src/test/java/test/factory/FactoryInSeparateClassTest.java b/testng-core/src/test/java/test/factory/FactoryInSeparateClassTest.java
index d85ce198a3..7876b84713 100644
--- a/testng-core/src/test/java/test/factory/FactoryInSeparateClassTest.java
+++ b/testng-core/src/test/java/test/factory/FactoryInSeparateClassTest.java
@@ -1,5 +1,7 @@
 package test.factory;
 
+import static org.testng.Assert.assertEquals;
+
 import org.testng.annotations.BeforeTest;
 import org.testng.annotations.Factory;
 import org.testng.annotations.Test;
@@ -34,9 +36,11 @@ public Object[] createObjects() {
       dependsOnGroups = {"MySample"})
   public void checkSum() {
     m_wasRun = true;
-    assert (m_checkSum == 6)
-        : "Test instances made by factory did not invoke their test methods correctly.  expected 6 but got "
-            + m_checkSum;
+    assertEquals(
+        m_checkSum,
+        6,
+        "Test instances made by factory did not invoke their test methods correctly.  expected 6 but got "
+            + m_checkSum);
   }
 
   public static boolean wasRun() {
diff --git a/testng-core/src/test/java/test/factory/FactoryInterleavingTest.java b/testng-core/src/test/java/test/factory/FactoryInterleavingTest.java
index 3dd9211ec1..f66c0c45e9 100644
--- a/testng-core/src/test/java/test/factory/FactoryInterleavingTest.java
+++ b/testng-core/src/test/java/test/factory/FactoryInterleavingTest.java
@@ -1,7 +1,8 @@
 package test.factory;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 import java.util.List;
-import org.testng.Assert;
 import org.testng.TestNG;
 import org.testng.annotations.Test;
 import org.testng.collections.Lists;
@@ -26,10 +27,8 @@ public void methodsShouldBeInterleaved() {
       10, 11, 12, 13,
     };
     Integer[] logArray = LOG.toArray(new Integer[0]);
-    if (!logArray.equals(valid1)) {
-      Assert.assertEquals(logArray, valid1);
-    } else if (!logArray.equals(valid2)) {
-      Assert.assertEquals(logArray, valid2);
-    }
+    assertThat(logArray)
+        .satisfiesAnyOf(
+            it -> assertThat(it).isEqualTo(valid1), it -> assertThat(it).isEqualTo(valid2));
   }
 }
diff --git a/testng-core/src/test/java/test/hook/issue2251/SampleTestCase.java b/testng-core/src/test/java/test/hook/issue2251/SampleTestCase.java
index f32e3e7872..3a84984eb7 100644
--- a/testng-core/src/test/java/test/hook/issue2251/SampleTestCase.java
+++ b/testng-core/src/test/java/test/hook/issue2251/SampleTestCase.java
@@ -14,6 +14,6 @@ public String toString() {
 
   @Test(timeOut = 1000000) // removing timeout fixes error output
   public void testError() throws Exception {
-    new NullExObj().toString();
+    String unused = new NullExObj().toString();
   }
 }
diff --git a/testng-core/src/test/java/test/junitreports/JUnitReportsTest.java b/testng-core/src/test/java/test/junitreports/JUnitReportsTest.java
index bd3c0deff6..d56e2ba25e 100644
--- a/testng-core/src/test/java/test/junitreports/JUnitReportsTest.java
+++ b/testng-core/src/test/java/test/junitreports/JUnitReportsTest.java
@@ -10,7 +10,6 @@
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Arrays;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Stream;
@@ -106,14 +105,7 @@ public void testTestCaseOrderingInJUnitReportReporterWhenPrioritiesDefined() thr
     tng.run();
     Testsuite suite = reportReporter.getTestsuite(Issue1262TestSample.class.getName());
     List<String> expected =
-        new LinkedList<String>() {
-          {
-            add("testRoles001_Post");
-            add("testRoles002_Post");
-            add("testRoles003_Post");
-            add("testRoles004_Post");
-          }
-        };
+        List.of("testRoles001_Post", "testRoles002_Post", "testRoles003_Post", "testRoles004_Post");
     List<String> actual = Lists.newLinkedList();
     for (Testcase testcase : suite.getTestcase()) {
       actual.add(testcase.getName().trim());
diff --git a/testng-core/src/test/java/test/junitreports/TestSuiteHandler.java b/testng-core/src/test/java/test/junitreports/TestSuiteHandler.java
index daa00cc359..fa214f9e93 100644
--- a/testng-core/src/test/java/test/junitreports/TestSuiteHandler.java
+++ b/testng-core/src/test/java/test/junitreports/TestSuiteHandler.java
@@ -1,16 +1,17 @@
 package test.junitreports;
 
+import java.util.ArrayDeque;
 import java.util.Arrays;
+import java.util.Deque;
 import java.util.List;
-import java.util.Stack;
 import org.xml.sax.Attributes;
 import org.xml.sax.helpers.DefaultHandler;
 
 public class TestSuiteHandler extends DefaultHandler {
   private static final List<String> tags = Arrays.asList("error", "skipped", "ignored", "failure");
   private final Testsuite testsuite = new Testsuite();
-  private final Stack<String> elementStack = new Stack<>();
-  private final Stack<Testcase> testcaseStack = new Stack<>();
+  private final Deque<String> elementStack = new ArrayDeque<>();
+  private final Deque<Testcase> testcaseStack = new ArrayDeque<>();
 
   @Override
   public void startElement(String uri, String localName, String qName, Attributes attributes) {
diff --git a/testng-core/src/test/java/test/junitreports/Testsuite.java b/testng-core/src/test/java/test/junitreports/Testsuite.java
index b4e61cb5ea..41449872c4 100644
--- a/testng-core/src/test/java/test/junitreports/Testsuite.java
+++ b/testng-core/src/test/java/test/junitreports/Testsuite.java
@@ -1,6 +1,6 @@
 package test.junitreports;
 
-import java.util.LinkedList;
+import java.util.ArrayList;
 import java.util.List;
 import org.xml.sax.Attributes;
 
@@ -92,5 +92,5 @@ public String toString() {
   private int failures;
   private int skipped;
   private int errors;
-  private List<Testcase> testcase = new LinkedList<>();
+  private List<Testcase> testcase = new ArrayList<>();
 }
diff --git a/testng-core/src/test/java/test/methods/SampleMethod1.java b/testng-core/src/test/java/test/methods/SampleMethod1.java
index 2f59a4a105..e7e020902c 100644
--- a/testng-core/src/test/java/test/methods/SampleMethod1.java
+++ b/testng-core/src/test/java/test/methods/SampleMethod1.java
@@ -1,5 +1,7 @@
 package test.methods;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.Test;
 
 /**
@@ -41,7 +43,8 @@ public void shouldNotRun2() {
   }
 
   public static void verify() {
-    assert m_ok1 && m_ok2 && m_ok3 && m_ok4
-        : "All booleans should be true: " + m_ok1 + " " + m_ok2 + " " + m_ok3 + " " + m_ok4;
+    assertTrue(
+        m_ok1 && m_ok2 && m_ok3 && m_ok4,
+        "All booleans should be true: " + m_ok1 + " " + m_ok2 + " " + m_ok3 + " " + m_ok4);
   }
 }
diff --git a/testng-core/src/test/java/test/objectfactory/ContextAwareObjectFactoryFactory.java b/testng-core/src/test/java/test/objectfactory/ContextAwareObjectFactoryFactory.java
index f55775cbec..4e4136b860 100644
--- a/testng-core/src/test/java/test/objectfactory/ContextAwareObjectFactoryFactory.java
+++ b/testng-core/src/test/java/test/objectfactory/ContextAwareObjectFactoryFactory.java
@@ -1,5 +1,7 @@
 package test.objectfactory;
 
+import static org.testng.Assert.assertNotNull;
+
 import org.testng.ITestContext;
 import org.testng.ITestObjectFactory;
 import org.testng.annotations.ObjectFactory;
@@ -11,7 +13,7 @@ public class ContextAwareObjectFactoryFactory {
 
   @ObjectFactory
   public ITestObjectFactory create(ITestContext context) {
-    assert context != null;
+    assertNotNull(context);
     invoked++;
     return new ObjectFactoryImpl();
   }
diff --git a/testng-core/src/test/java/test/priority/parallel/EfficientPriorityParallelizationTest2.java b/testng-core/src/test/java/test/priority/parallel/EfficientPriorityParallelizationTest2.java
index fa3931ce17..249b7a64a8 100644
--- a/testng-core/src/test/java/test/priority/parallel/EfficientPriorityParallelizationTest2.java
+++ b/testng-core/src/test/java/test/priority/parallel/EfficientPriorityParallelizationTest2.java
@@ -100,8 +100,6 @@ public void setUp() {
 
     suiteOneTestOneTestMethodLevelEventLogs =
         getTestMethodLevelEventLogsForTest(SUITE_A, SUITE_A_TEST_A);
-    suiteOneTestOneTestMethodLevelEventLogs.stream()
-        .filter(e -> e.getEvent() == TestNgRunEvent.LISTENER_TEST_METHOD_START);
 
     testEventLogsMap.put(SUITE_A_TEST_A, getTestLevelEventLogsForTest(SUITE_A, SUITE_A_TEST_A));
 
diff --git a/testng-core/src/test/java/test/sample/AfterClassCalledAtEnd.java b/testng-core/src/test/java/test/sample/AfterClassCalledAtEnd.java
index af4862b878..e42c170936 100644
--- a/testng-core/src/test/java/test/sample/AfterClassCalledAtEnd.java
+++ b/testng-core/src/test/java/test/sample/AfterClassCalledAtEnd.java
@@ -1,5 +1,8 @@
 package test.sample;
 
+import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.AfterClass;
 import org.testng.annotations.BeforeClass;
 import org.testng.annotations.Test;
@@ -22,28 +25,29 @@ public void before1Class() {
   @AfterClass(groups = {"someGroup"})
   public void afterClass() {
     m_afterClass = true;
-    assert m_test1 && m_test2 && m_test3
-        : "One of the test methods was not invoked: " + m_test1 + " " + m_test2 + " " + m_test3;
+    assertTrue(
+        m_test1 && m_test2 && m_test3,
+        "One of the test methods was not invoked: " + m_test1 + " " + m_test2 + " " + m_test3);
   }
 
   @Test(description = "Verify that beforeClass and afterClass are called correctly")
   public void test1() {
     m_test1 = true;
-    assert m_before1Class : "beforeClass configuration must be called before method";
-    assert !m_afterClass : "afterClass configuration must not be called before test method";
+    assertTrue(m_before1Class, "beforeClass configuration must be called before method");
+    assertFalse(m_afterClass, "afterClass configuration must not be called before test method");
   }
 
   @Test
   public void test2() {
     m_test2 = true;
-    assert m_before1Class : "beforeClass configuration must be called before method";
-    assert !m_afterClass : "afterClass configuration must not be called before test method";
+    assertTrue(m_before1Class, "beforeClass configuration must be called before method");
+    assertFalse(m_afterClass, "afterClass configuration must not be called before test method");
   }
 
   @Test
   public void test3() {
     m_test3 = true;
-    assert m_before1Class : "beforeClass configuration must be called before method";
-    assert !m_afterClass : "afterClass configuration must not be called before test method";
+    assertTrue(m_before1Class, "beforeClass configuration must be called before method");
+    assertFalse(m_afterClass, "afterClass configuration must not be called before test method");
   }
 }
diff --git a/testng-core/src/test/java/test/sample/BaseAfterClassCalledAtEnd.java b/testng-core/src/test/java/test/sample/BaseAfterClassCalledAtEnd.java
index de9d8241c5..17dbe70dc0 100644
--- a/testng-core/src/test/java/test/sample/BaseAfterClassCalledAtEnd.java
+++ b/testng-core/src/test/java/test/sample/BaseAfterClassCalledAtEnd.java
@@ -1,5 +1,7 @@
 package test.sample;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.AfterClass;
 
 public class BaseAfterClassCalledAtEnd {
@@ -7,6 +9,6 @@ public class BaseAfterClassCalledAtEnd {
 
   @AfterClass(dependsOnGroups = {".*"})
   public void baseAfterClass() {
-    assert m_afterClass : "This afterClass method should have been called last";
+    assertTrue(m_afterClass, "This afterClass method should have been called last");
   }
 }
diff --git a/testng-core/src/test/java/test/sample/BaseSampleInheritance.java b/testng-core/src/test/java/test/sample/BaseSampleInheritance.java
index d83a60b431..420b4adfea 100644
--- a/testng-core/src/test/java/test/sample/BaseSampleInheritance.java
+++ b/testng-core/src/test/java/test/sample/BaseSampleInheritance.java
@@ -1,5 +1,7 @@
 package test.sample;
 
+import static org.testng.Assert.assertTrue;
+
 import java.util.ArrayList;
 import java.util.List;
 import org.testng.annotations.BeforeClass;
@@ -38,7 +40,7 @@ public void configuration1() {
 
   @Test(dependsOnGroups = {"inheritedTestMethod"})
   public void testBooleans() {
-    assert m_invokedBaseMethod : "Didn't invoke test method in base class";
-    assert m_invokedBaseConfiguration : "Didn't invoke configuration method in base class";
+    assertTrue(m_invokedBaseMethod, "Didn't invoke test method in base class");
+    assertTrue(m_invokedBaseConfiguration, "Didn't invoke configuration method in base class");
   }
 }
diff --git a/testng-core/src/test/java/test/sample/Basic1.java b/testng-core/src/test/java/test/sample/Basic1.java
index f9a224520e..3834974ef4 100644
--- a/testng-core/src/test/java/test/sample/Basic1.java
+++ b/testng-core/src/test/java/test/sample/Basic1.java
@@ -1,5 +1,7 @@
 package test.sample;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.BeforeMethod;
 import org.testng.annotations.Test;
 
@@ -21,6 +23,6 @@ public void beforeTestMethod() {
 
   @Test(groups = {"basic1"})
   public void basic1() {
-    assert getCount() > 0 : "COUNT WAS NOT INCREMENTED";
+    assertTrue(getCount() > 0, "COUNT WAS NOT INCREMENTED");
   }
 }
diff --git a/testng-core/src/test/java/test/sample/Basic2.java b/testng-core/src/test/java/test/sample/Basic2.java
index d30b407339..b2bb688906 100644
--- a/testng-core/src/test/java/test/sample/Basic2.java
+++ b/testng-core/src/test/java/test/sample/Basic2.java
@@ -1,5 +1,8 @@
 package test.sample;
 
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.AfterClass;
 import org.testng.annotations.AfterTest;
 import org.testng.annotations.Test;
@@ -11,7 +14,7 @@ public class Basic2 {
   @Test(dependsOnGroups = {"basic1"})
   public void basic2() {
     m_basic2WasRun = true;
-    assert Basic1.getCount() > 0 : "COUNT WAS NOT INCREMENTED";
+    assertTrue(Basic1.getCount() > 0, "COUNT WAS NOT INCREMENTED");
   }
 
   @AfterTest
@@ -23,8 +26,8 @@ public void cleanUp() {
   @AfterClass
   public void checkTestAtClassLevelWasRun() {
     m_afterClass++;
-    assert m_basic2WasRun : "Class annotated with @Test didn't have its methods run.";
-    assert 1 == m_afterClass
-        : "After class should have been called exactly once, not " + m_afterClass;
+    assertTrue(m_basic2WasRun, "Class annotated with @Test didn't have its methods run.");
+    assertEquals(
+        m_afterClass, 1, "After class should have been called exactly once, not " + m_afterClass);
   }
 }
diff --git a/testng-core/src/test/java/test/sample/InvocationCountTest.java b/testng-core/src/test/java/test/sample/InvocationCountTest.java
index cde4fd19ce..c61609a57d 100644
--- a/testng-core/src/test/java/test/sample/InvocationCountTest.java
+++ b/testng-core/src/test/java/test/sample/InvocationCountTest.java
@@ -1,5 +1,7 @@
 package test.sample;
 
+import static org.testng.Assert.assertEquals;
+
 import org.testng.annotations.AfterClass;
 import org.testng.annotations.AfterSuite;
 import org.testng.annotations.Test;
@@ -69,7 +71,9 @@ public void successPercentageShouldFail() {
 
   @AfterClass(groups = {"invocationOnly"})
   public void verify() {
-    assert 10 == m_count
-        : "Method should have been invoked 10 times but was invoked " + m_count + " times";
+    assertEquals(
+        m_count,
+        10,
+        "Method should have been invoked 10 times but was invoked " + m_count + " times");
   }
 }
diff --git a/testng-core/src/test/java/test/sample/JUnitSample2.java b/testng-core/src/test/java/test/sample/JUnitSample2.java
index 34d26ef871..c6e1a35700 100644
--- a/testng-core/src/test/java/test/sample/JUnitSample2.java
+++ b/testng-core/src/test/java/test/sample/JUnitSample2.java
@@ -25,6 +25,6 @@ public void setUp() {
   }
 
   public void testSample2ThatSetUpWasRun() {
-    assert null != m_field : "setUp() wasn't run";
+    assertNotNull("setUp() wasn't run", m_field);
   }
 }
diff --git a/testng-core/src/test/java/test/sample/PartialGroupVerification.java b/testng-core/src/test/java/test/sample/PartialGroupVerification.java
index 3399abea72..0aeb6cfdf7 100644
--- a/testng-core/src/test/java/test/sample/PartialGroupVerification.java
+++ b/testng-core/src/test/java/test/sample/PartialGroupVerification.java
@@ -1,5 +1,7 @@
 package test.sample;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.Test;
 
 /**
@@ -10,7 +12,8 @@
 public class PartialGroupVerification {
   @Test
   public void verify() {
-    assert PartialGroupTest.m_successMethod && PartialGroupTest.m_successClass
-        : "test1 and test2 should have been invoked both";
+    assertTrue(
+        PartialGroupTest.m_successMethod && PartialGroupTest.m_successClass,
+        "test1 and test2 should have been invoked both");
   }
 }
diff --git a/testng-core/src/test/java/test/sample/Scope.java b/testng-core/src/test/java/test/sample/Scope.java
index 04b63fa29c..e725f2947d 100644
--- a/testng-core/src/test/java/test/sample/Scope.java
+++ b/testng-core/src/test/java/test/sample/Scope.java
@@ -1,5 +1,7 @@
 package test.sample;
 
+import static org.testng.Assert.assertEquals;
+
 import org.testng.annotations.Parameters;
 import org.testng.annotations.Test;
 
@@ -9,12 +11,12 @@ public class Scope {
   @Parameters({"parameter"})
   @Test(groups = {"outer-group"})
   public void outerDeprecated(String s) {
-    assert "out".equals(s) : "Expected out got " + s;
+    assertEquals(s, "out", "Expected out got " + s);
   }
 
   @Parameters({"parameter"})
   @Test(groups = {"inner-group"})
   public void innerDeprecated(String s) {
-    assert "in".equals(s) : "Expected in got " + s;
+    assertEquals(s, "in", "Expected in got " + s);
   }
 }
diff --git a/testng-core/src/test/java/test/superclass/BaseSampleTest3.java b/testng-core/src/test/java/test/superclass/BaseSampleTest3.java
index f3dc96cd57..febc1954ff 100644
--- a/testng-core/src/test/java/test/superclass/BaseSampleTest3.java
+++ b/testng-core/src/test/java/test/superclass/BaseSampleTest3.java
@@ -1,10 +1,12 @@
 package test.superclass;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.Test;
 
 public class BaseSampleTest3 {
   @Test
   public void base() {
-    assert true;
+    assertTrue(true);
   }
 }
diff --git a/testng-core/src/test/java/test/thread/parallelization/BaseParallelizationTest.java b/testng-core/src/test/java/test/thread/parallelization/BaseParallelizationTest.java
index 0d50aa2097..bb89aa905d 100644
--- a/testng-core/src/test/java/test/thread/parallelization/BaseParallelizationTest.java
+++ b/testng-core/src/test/java/test/thread/parallelization/BaseParallelizationTest.java
@@ -778,7 +778,7 @@ public static void verifyEventsForTestMethodsRunInTheSameThread(
       Annotation[] annotations = method.getDeclaredAnnotations();
 
       for (Annotation a : annotations) {
-        if (Test.class.isAssignableFrom(a.getClass())) {
+        if (Test.class.isAssignableFrom(a.annotationType())) {
           isTestMethod = true;
         }
       }
diff --git a/testng-core/src/test/java/test/tmp/Tmp.java b/testng-core/src/test/java/test/tmp/Tmp.java
index e2c828c329..b742ec527d 100644
--- a/testng-core/src/test/java/test/tmp/Tmp.java
+++ b/testng-core/src/test/java/test/tmp/Tmp.java
@@ -11,7 +11,7 @@ public void f() {
     debug("START " + Thread.currentThread().getId());
     try {
       Random r = new Random();
-      Thread.sleep(Math.abs(r.nextInt() % 300));
+      Thread.sleep(Math.abs(r.nextInt(300)));
     } catch (InterruptedException handled) {
       Thread.currentThread().interrupt();
       handled.printStackTrace();
diff --git a/testng-core/src/test/java/test/triangle/Child1.java b/testng-core/src/test/java/test/triangle/Child1.java
index 9e37cab1fe..83caae2e43 100644
--- a/testng-core/src/test/java/test/triangle/Child1.java
+++ b/testng-core/src/test/java/test/triangle/Child1.java
@@ -1,5 +1,7 @@
 package test.triangle;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.Test;
 
 /**
@@ -10,11 +12,11 @@
 public class Child1 extends Base {
   @Test
   public void child1() {
-    assert m_isInitialized : "Wasn't initialized correctly " + hashCode() + " " + getClass();
+    assertTrue(m_isInitialized, "Wasn't initialized correctly " + hashCode() + " " + getClass());
   }
 
   @Test
   public void child1a() {
-    assert m_isInitialized : "Wasn't initialized correctly " + hashCode() + " " + getClass();
+    assertTrue(m_isInitialized, "Wasn't initialized correctly " + hashCode() + " " + getClass());
   }
 }
diff --git a/testng-core/src/test/java/test/triangle/Child2.java b/testng-core/src/test/java/test/triangle/Child2.java
index 73eb1bce7b..3a9ba9b066 100644
--- a/testng-core/src/test/java/test/triangle/Child2.java
+++ b/testng-core/src/test/java/test/triangle/Child2.java
@@ -1,5 +1,7 @@
 package test.triangle;
 
+import static org.testng.Assert.assertTrue;
+
 import org.testng.annotations.Test;
 
 /**
@@ -11,6 +13,6 @@ public class Child2 extends Base {
 
   @Test
   public void child2() {
-    assert m_isInitialized : "Wasn't initialized correctly";
+    assertTrue(m_isInitialized, "Wasn't initialized correctly");
   }
 }
diff --git a/testng-runner-api/src/main/java/org/testng/internal/LiteWeightTestNGMethod.java b/testng-runner-api/src/main/java/org/testng/internal/LiteWeightTestNGMethod.java
index c5dee94eb4..06daa522dd 100644
--- a/testng-runner-api/src/main/java/org/testng/internal/LiteWeightTestNGMethod.java
+++ b/testng-runner-api/src/main/java/org/testng/internal/LiteWeightTestNGMethod.java
@@ -1,8 +1,8 @@
 package org.testng.internal;
 
 import java.lang.reflect.Method;
+import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Callable;
@@ -27,7 +27,7 @@ public class LiteWeightTestNGMethod implements ITestNGMethod {
   private String missingGroup;
   private final String[] beforeGroups;
   private final String[] afterGroups;
-  private final List<String> methodsDependedUpon = new LinkedList<>();
+  private final List<String> methodsDependedUpon = new ArrayList<>();
   private int priority;
   private int interceptedPriority;
   private final XmlTest xmlTest;