Suggestions

error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/EqualityRules.java

@@ -21,8 +21,8 @@ final class EqualityRules {
   private EqualityRules() {}
 
   /** Prefer reference-based equality for enums. */
-  // Primitive value comparisons are not listed, because Error Prone flags those out of the box.
-  static final class PrimitiveOrReferenceEquality<T extends Enum<T>> {
+  // Primitive value comparisons are not matched, because Error Prone flags those out of the box.
+  static final class EnumReferenceEquality<T extends Enum<T>> {
     /**
      * Enums can be compared by reference. It is safe to do so even in the face of refactorings,
      * because if the type is ever converted to a non-enum, then Error-Prone will complain about any
@@ -44,16 +44,16 @@ boolean after(T a, T b) {
     }
   }
 
-  /** Prefer reference-based equality for enums over more contrived equality checks. */
-  static final class EnumsReferenceEqualityLambda<T extends Enum<T>> {
+  /** Prefer reference-based equality for enums. */
+  static final class EnumReferenceEqualityLambda<T extends Enum<T>> {
     @BeforeTemplate
-    Predicate<T> before(T a) {
-      return Refaster.anyOf(isEqual(a), a::equals);
+    Predicate<T> before(T e) {
+      return Refaster.anyOf(isEqual(e), e::equals);
     }
 
     @AfterTemplate
-    Predicate<T> after(T a) {
-      return v -> v == a;
+    Predicate<T> after(T e) {
+      return v -> v == e;
     }
   }
 

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestInput.java

@@ -18,7 +18,7 @@ public ImmutableSet<Object> elidedTypesAndStaticImports() {
     return ImmutableSet.of(Objects.class, Optional.class, isEqual(null), not(null));
   }
 
-  ImmutableSet<Boolean> testPrimitiveOrReferenceEquality() {
+  ImmutableSet<Boolean> testEnumReferenceEquality() {
     return ImmutableSet.of(
         RoundingMode.UP.equals(RoundingMode.DOWN),
         Objects.equals(RoundingMode.UP, RoundingMode.DOWN),
@@ -28,18 +28,16 @@ ImmutableSet<Boolean> testPrimitiveOrReferenceEquality() {
         RoundingMode.UP.ordinal() != RoundingMode.DOWN.ordinal());
   }
 
+  ImmutableSet<Predicate<RoundingMode>> testEnumReferenceEqualityLambda() {
+    return ImmutableSet.of(isEqual(RoundingMode.DOWN), RoundingMode.UP::equals);
+  }
+
   boolean testEqualsPredicate() {
     // XXX: When boxing is involved this rule seems to break. Example:
     // Stream.of(1).anyMatch(e -> Integer.MIN_VALUE.equals(e));
     return Stream.of("foo").anyMatch(s -> "bar".equals(s));
   }
 
-  ImmutableSet<Boolean> testEnumsReferenceEqualityLambda() {
-    return ImmutableSet.of(
-        Stream.of(RoundingMode.UP).anyMatch(isEqual(RoundingMode.DOWN)),
-        Stream.of(RoundingMode.UP).anyMatch(RoundingMode.DOWN::equals));
-  }
-
   boolean testDoubleNegation() {
     return !!Boolean.TRUE;
   }

error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/EqualityRulesTestOutput.java

@@ -18,7 +18,7 @@ public ImmutableSet<Object> elidedTypesAndStaticImports() {
     return ImmutableSet.of(Objects.class, Optional.class, isEqual(null), not(null));
   }
 
-  ImmutableSet<Boolean> testPrimitiveOrReferenceEquality() {
+  ImmutableSet<Boolean> testEnumReferenceEquality() {
     return ImmutableSet.of(
         RoundingMode.UP == RoundingMode.DOWN,
         RoundingMode.UP == RoundingMode.DOWN,
@@ -28,18 +28,16 @@ ImmutableSet<Boolean> testPrimitiveOrReferenceEquality() {
         RoundingMode.UP != RoundingMode.DOWN);
   }
 
+  ImmutableSet<Predicate<RoundingMode>> testEnumReferenceEqualityLambda() {
+    return ImmutableSet.of(v -> v == RoundingMode.DOWN, v -> v == RoundingMode.UP);
+  }
+
   boolean testEqualsPredicate() {
     // XXX: When boxing is involved this rule seems to break. Example:
     // Stream.of(1).anyMatch(e -> Integer.MIN_VALUE.equals(e));
     return Stream.of("foo").anyMatch("bar"::equals);
   }
 
-  ImmutableSet<Boolean> testEnumsReferenceEqualityLambda() {
-    return ImmutableSet.of(
-        Stream.of(RoundingMode.UP).anyMatch(v -> v == RoundingMode.DOWN),
-        Stream.of(RoundingMode.UP).anyMatch(v -> v == RoundingMode.DOWN));
-  }
-
   boolean testDoubleNegation() {
     return Boolean.TRUE;
   }