warn when spring plugin not present

pitest-entry/src/main/java/org/pitest/mutationtest/verify/KotlinVerifierFactory.java

@@ -31,7 +31,7 @@ class KotlinVerifier implements BuildVerifier {
     @Override
     public List<String> verify() {
         if (kotlinIsOnClassPath() && !kotlinPluginIsPresent() && kotlinClassesToBeMutated()) {
-            return asList("Project uses kotlin, but the Arcmutate kotlin plugin is not on classpath (https://docs.arcmutate.com/docs/kotlin.html)");
+            return asList("Project uses kotlin, but the Arcmutate kotlin plugin is not present (https://docs.arcmutate.com/docs/kotlin.html)");
         }
 
         return Collections.emptyList();

pitest-entry/src/main/java/org/pitest/mutationtest/verify/SpringVerifierFactory.java

@@ -0,0 +1,48 @@
+package org.pitest.mutationtest.verify;
+
+import org.pitest.classinfo.ClassName;
+import org.pitest.classpath.CodeSource;
+
+import java.util.Collections;
+import java.util.List;
+
+import static java.util.Arrays.asList;
+
+public class SpringVerifierFactory implements BuildVerifierFactory {
+    @Override
+    public BuildVerifier create(CodeSource code) {
+        return new SpringVerifier(code);
+    }
+
+    @Override
+    public String description() {
+        return "Detect missing spring plugin";
+    }
+}
+
+class SpringVerifier implements BuildVerifier {
+
+    private final CodeSource code;
+
+    SpringVerifier(CodeSource code) {
+        this.code = code;
+    }
+
+    @Override
+    public List<String> verify() {
+        if (springIsOnClassPath() && !springPluginIsPresent()) {
+            return asList("Project uses Spring, but the Arcmutate Spring plugin is not present (https://docs.arcmutate.com/docs/spring.html)");
+        }
+
+        return Collections.emptyList();
+    }
+
+
+    private boolean springPluginIsPresent() {
+        return code.fetchClassBytes(ClassName.fromString("com.groupcdg.arcmutate.spring.PluginMarker")).isPresent();
+    }
+
+    private boolean springIsOnClassPath() {
+        return code.fetchClassBytes(ClassName.fromString("org.springframework.core.SpringVersion")).isPresent();
+    }
+}

pitest-entry/src/main/resources/META-INF/services/org.pitest.mutationtest.verify.BuildVerifierFactory

@@ -1,4 +1,5 @@
 org.pitest.mutationtest.verify.DefaultBuildVerifierFactory
 org.pitest.mutationtest.verify.MissingJUnit5PluginVerifierFactory
 org.pitest.mutationtest.verify.MissingTestNGPluginVerifierFactory
-org.pitest.mutationtest.verify.KotlinVerifierFactory
+org.pitest.mutationtest.verify.KotlinVerifierFactory
+org.pitest.mutationtest.verify.SpringVerifierFactory

pitest-entry/src/test/java/org/pitest/mutationtest/verify/SpringVerifierFactoryTest.java

@@ -0,0 +1,59 @@
+package org.pitest.mutationtest.verify;
+
+import org.junit.Test;
+import org.pitest.bytecode.analysis.ClassTree;
+import org.pitest.classinfo.ClassName;
+import org.pitest.verifier.interceptors.BuildVerifierVerifier;
+
+import static org.pitest.verifier.interceptors.BuildVerifierVerifier.aValidClass;
+import static org.pitest.verifier.interceptors.BuildVerifierVerifier.codeSourceForClasses;
+import static org.pitest.verifier.interceptors.BuildVerifierVerifier.codeSourceReturning;
+
+public class SpringVerifierFactoryTest {
+    BuildVerifierVerifier v = BuildVerifierVerifier.confirmFactory(new SpringVerifierFactory());
+
+    @Test
+    public void isOnChain() {
+        v.isOnChain();
+    }
+
+    @Test
+    public void doesNotDisplayMessageWhenSpringNotPresent() {
+        v.withCodeSource(codeSourceReturning(ClassName.fromString("not.relevant.Foo")))
+                .issues()
+                .isEmpty();
+    }
+
+    @Test
+    public void displaysWarningWhenSpringPresentWithoutPlugin() {
+        ClassTree springMarker = aValidClass();
+        springMarker.rawNode().name = "org.springframework.core.SpringVersion";
+
+
+        ClassTree clientCode = aValidClass();
+        clientCode.rawNode().name = "com.example.Foo";
+        clientCode.rawNode().sourceFile = "Foo.kt";
+
+        v.withCodeSource(codeSourceForClasses(springMarker, clientCode))
+                .issues()
+                .isNotEmpty();
+    }
+
+    @Test
+    public void doesNotDisplayWarningWhenPluginPresent() {
+        ClassTree springMarker = aValidClass();
+        springMarker.rawNode().name = "org.springframework.core.SpringVersion";
+
+        ClassTree pluginMarker = aValidClass();
+        pluginMarker.rawNode().name = "com.groupcdg.arcmutate.spring.PluginMarker";
+
+        ClassTree clientCode = aValidClass();
+        clientCode.rawNode().name = "com.example.Foo";
+        clientCode.rawNode().sourceFile = "Foo.kt";
+
+        v.withCodeSource(codeSourceForClasses(springMarker, pluginMarker, clientCode))
+                .issues()
+                .isEmpty();
+    }
+}
+