support simple mutator exclusion for #954

README.md

@@ -10,7 +10,8 @@ Read all about it at http://pitest.org
 
 ### 1.7.3 (unreleased)
 
-* #952 Mutate map return to emptyMap instead of null
+* #952 Mutate map return to `emptyMap` instead of null
+* #954 Allow mutators to be excluded
 
 ### 1.7.2 
 

pitest-entry/src/test/java/org/pitest/mutationtest/build/MutationDiscoveryTest.java

@@ -1,6 +1,5 @@
 package org.pitest.mutationtest.build;
 
-import com.example.HasPrivateStreamMethodUsedOnlyInSingleFlatMap;
 import org.junit.Before;
 import org.junit.Test;
 import org.pitest.classinfo.ClassByteArraySource;

pitest/src/main/java/org/pitest/mutationtest/engine/gregor/config/GregorEngineFactory.java

@@ -34,7 +34,7 @@ public MutationEngine createEngine(EngineArguments args) {
            createMutatorListFromArrayOrUseDefaults(args.mutators()));
   }
 
-  public MutationEngine createEngineWithMutators(
+  MutationEngine createEngineWithMutators(
       final Collection<String> excludedMethods,
       final Collection<? extends MethodMutatorFactory> mutators) {
 

pitest/src/main/java/org/pitest/mutationtest/engine/gregor/config/Mutator.java

@@ -123,8 +123,23 @@ public static Collection<MethodMutatorFactory> byName(final String name) {
   public static Collection<MethodMutatorFactory> fromStrings(
       final Collection<String> names) {
 
+    List<String> exclusions = names.stream()
+            .filter(s -> s.startsWith("-"))
+            .map(s -> s.substring(1))
+            .collect(Collectors.toList());
+
+    List<String> inclusions = names.stream()
+            .filter(s -> !s.startsWith("-"))
+            .collect(Collectors.toList());
+
     final Set<MethodMutatorFactory> unique = new TreeSet<>(compareId());
-    FCollection.flatMapTo(names, fromString(MUTATORS), unique);
+    FCollection.flatMapTo(inclusions, fromString(MUTATORS), unique);
+
+    final Set<MethodMutatorFactory> excluded = new TreeSet<>(compareId());
+    FCollection.flatMapTo(exclusions, fromString(MUTATORS), excluded);
+
+    unique.removeAll(excluded);
+
     return unique;
   }
 

pitest/src/test/java/org/pitest/mutationtest/engine/gregor/config/GregorEngineFactoryTest.java

@@ -0,0 +1,48 @@
+package org.pitest.mutationtest.engine.gregor.config;
+
+import org.junit.Test;
+import org.pitest.mutationtest.EngineArguments;
+import org.pitest.mutationtest.engine.MutationEngine;
+
+import java.util.List;
+
+import static java.util.Arrays.asList;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class GregorEngineFactoryTest  {
+
+    GregorEngineFactory underTest = new GregorEngineFactory();
+
+    @Test
+    public void parsesSingleMutatorString() {
+          MutationEngine actual = parseMutators(asList("NULL_RETURNS"));
+
+        assertThat(actual.getMutatorNames()).contains("NULL_RETURNS");
+    }
+
+    @Test
+    public void parsesGroups() {
+        MutationEngine actual = parseMutators(asList("STRONGER"));
+
+        assertThat(actual.getMutatorNames()).contains("NULL_RETURNS", "REMOVE_CONDITIONALS_EQUAL_ELSE");
+    }
+
+    @Test
+    public void parsesExclusions() {
+        MutationEngine excluded = parseMutators(asList("STRONGER", "-REMOVE_CONDITIONALS_EQUAL_ELSE"));
+
+        assertThat(excluded.getMutatorNames()).doesNotContain("REMOVE_CONDITIONALS_EQUAL_ELSE");
+        assertThat(excluded.getMutatorNames()).isNotEmpty();
+    }
+
+    @Test
+    public void excludesGroups() {
+        MutationEngine excluded = parseMutators(asList("ALL", "-ALL"));
+        assertThat(excluded.getMutatorNames()).isEmpty();
+    }
+
+    private MutationEngine parseMutators(List<String> mutators) {
+        return underTest.createEngine(EngineArguments.arguments().withMutators(mutators));
+    }
+
+}

pitest/src/test/java/org/pitest/mutationtest/engine/gregor/config/MutatorTest.java

@@ -22,6 +22,7 @@
 import java.util.List;
 
 import org.junit.Test;
+import org.pitest.mutationtest.engine.MutationEngine;
 import org.pitest.mutationtest.engine.gregor.MethodMutatorFactory;
 import org.pitest.mutationtest.engine.gregor.mutators.experimental.ArgumentPropagationMutator;
 import org.pitest.mutationtest.engine.gregor.mutators.InvertNegsMutator;
@@ -290,6 +291,17 @@ public void overlappingGroupsDoNotCauseDuplicates() {
             .hasSameSizeAs(parseStrings("DEFAULTS", "INCREMENTS"));
   }
 
+  @Test
+  public void parsesExclusions() {
+    assertThat(parseStrings("DEFAULTS", "-INCREMENTS"))
+            .noneMatch(m -> m.getName().equals("INCREMENTS"));
+  }
+
+  @Test
+  public void excludesGroups() {
+    assertThat(parseStrings("DEFAULTS", "STRONGER", "-ALL")).isEmpty();
+  }
+
   private Collection<MethodMutatorFactory> parseStrings(final String... s) {
     return Mutator.fromStrings(asList(s));
   }