#315: support classes that have fields but don't override equals

jqno · Jun 11, 2020 · 7c85ef3 · 7c85ef3
1 parent 503babb
commit 7c85ef3
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Showing 3 changed files with 19 additions and 4 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -14,10 +14,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Initial support for Java 14's records and their [new equality invariant](https://docs.oracle.com/en/java/javase/14/docs/api/java.base/java/lang/Record.html).
 - Support for JSR305's `ParametersAreNonnullByDefault` annotation. ([Issue 308](https://github.com/jqno/equalsverifier/issues/308))
+
 ### Changed
 - Renames the project's main branch to `main`.
 - Replaces all references to the word 'black' to 'blue', including those in internal (but accessible) API's.
+
 ### Fixed
+- Testing a class with that has fields but doesn't override `equals` causes "Mutability: equals depends on mutable field" error. ([Issue 315](https://github.com/jqno/equalsverifier/issues/315))
 
 ## [3.3] - 2020-05-14
 ### Added

diff --git a/...ain/java/nl/jqno/equalsverifier/internal/checkers/fieldchecks/MutableStateFieldCheck.java b/...ain/java/nl/jqno/equalsverifier/internal/checkers/fieldchecks/MutableStateFieldCheck.java
@@ -31,11 +31,11 @@ public void execute(FieldAccessor referenceAccessor, FieldAccessor changedAccess
         Object reference = referenceAccessor.getObject();
         Object changed = changedAccessor.getObject();
 
+        boolean equalBefore = reference.equals(changed);
         changedAccessor.changeField(prefabValues, typeTag);
+        boolean equalAfter = reference.equals(changed);
 
-        boolean equalsChanged = !reference.equals(changed);
-
-        if (equalsChanged && !referenceAccessor.fieldIsFinal()) {
+        if (equalBefore && !equalAfter && !referenceAccessor.fieldIsFinal()) {
             fail(
                     Formatter.of(
                             "Mutability: equals depends on mutable field %%.",

diff --git a/...est/java/nl/jqno/equalsverifier/integration/extended_contract/DontOverrideEqualsTest.java b/...est/java/nl/jqno/equalsverifier/integration/extended_contract/DontOverrideEqualsTest.java
@@ -35,6 +35,15 @@ public void succeed_whenEqualsIsInheritedButNotFromObject() {
                 .verify();
     }
 
+    @Test
+    public void
+            succeed_whenClassIsAnExceptionAndEqualsIsInheritedDirectlyFromObject_givenDetailMessageIsIgnored() {
+        EqualsVerifier.forClass(SimpleException.class)
+                .suppress(Warning.INHERITED_DIRECTLY_FROM_OBJECT)
+                .suppress(Warning.ALL_FIELDS_SHOULD_BE_USED)
+                .verify();
+    }
+
     static final class NoEqualsNoHashCodeMethod {}
 
     static final class InheritedEqualsAndHashCodeMethod extends Point {
@@ -43,7 +52,7 @@ static final class InheritedEqualsAndHashCodeMethod extends Point {
         }
     }
 
-    public final class Pojo {
+    static final class Pojo {
         private String s;
 
         public void setS(String value) {
@@ -59,4 +68,7 @@ public String toString() {
             return getClass().getName() + " " + s;
         }
     }
+
+    @SuppressWarnings("serial")
+    static final class SimpleException extends Exception {}
 }