phoedos/pmd
1
1 Fork 1
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge pull request #2959 from recdevs:feat/apex-equals-hashcode

Browse Source 
[apex] New Rule: override equals and hashcode rule #2959
This commit is contained in:
Andreas Dangel committed 2021-01-17 18:43:44 +01:00
2 parents 9b3fc1da8d 7443b5acc2
commit e114910048
7 files changed
+318 -13
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

docs/pages/release_notes.md
+7
View File
@@ -14,6 +14,12 @@ This is a {{ site.pmd.release_type }} release.
### New and noteworthy
#### New Rules
* The new Apex rule {% rule "apex/errorprone/OverrideBothEqualsAndHashcode" %} brings the well known Java rule
to Apex. In Apex the same principle applies: `equals` and `hashCode` should always be overridden
together to ensure collection classes such as Maps and Sets work as expected.
### Fixed Issues
* core
@@ -28,6 +34,7 @@ This is a {{ site.pmd.release_type }} release.
### External Contributions
* [#2959](https://github.com/pmd/pmd/pull/2959): \[apex] New Rule: override equals and hashcode rule - [recdevs](https://github.com/recdevs)
* [#2964](https://github.com/pmd/pmd/pull/2964): \[cs] Update C# grammar for additional C# 7 and C# 8 features - [Maikel Steneker](https://github.com/maikelsteneker)
* [#2983](https://github.com/pmd/pmd/pull/2983): \[java] LiteralsFirstInComparisons should consider constant fields - [Ozan Gulle](https://github.com/ozangulle)
* [#2994](https://github.com/pmd/pmd/pull/2994): \[core] Fix code climate severity strings - [Vincent Maurin](https://github.com/vmaurin)
pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/rule/errorprone/OverrideBothEqualsAndHashcodeRule.java
+68
View File
@@ -0,0 +1,68 @@
/*
* BSD-style license; for more info see http://pmd.sourceforge.net/license.html
*/
package net.sourceforge.pmd.lang.apex.rule.errorprone;
import net.sourceforge.pmd.lang.apex.ast.ASTMethod;
import net.sourceforge.pmd.lang.apex.ast.ASTParameter;
import net.sourceforge.pmd.lang.apex.ast.ASTUserClass;
import net.sourceforge.pmd.lang.apex.ast.ApexNode;
import net.sourceforge.pmd.lang.apex.rule.AbstractApexRule;
public class OverrideBothEqualsAndHashcodeRule extends AbstractApexRule {
public OverrideBothEqualsAndHashcodeRule() {
addRuleChainVisit(ASTUserClass.class);
}
@Override
public Object visit(ASTUserClass node, Object data) {
ApexNode<?> equalsNode = null;
ApexNode<?> hashNode = null;
for (ASTMethod method : node.findChildrenOfType(ASTMethod.class)) {
if (equalsNode == null && isEquals(method)) {
equalsNode = method;
}
if (hashNode == null && isHashCode(method)) {
hashNode = method;
}
if (hashNode != null && equalsNode != null) {
break;
}
}
if (equalsNode != null && hashNode == null) {
addViolation(data, equalsNode);
} else if (hashNode != null && equalsNode == null) {
addViolation(data, hashNode);
}
return data;
}
private boolean isEquals(ASTMethod node) {
int numParams = 0;
String paramType = null;
for (int ix = 0; ix < node.getNumChildren(); ix++) {
ApexNode<?> sn = node.getChild(ix);
if (sn instanceof ASTParameter) {
numParams++;
paramType = ((ASTParameter) sn).getType();
}
}
return numParams == 1 && "equals".equalsIgnoreCase(node.getImage()) && "Object".equalsIgnoreCase(paramType);
}
private boolean isHashCode(ASTMethod node) {
int numParams = 0;
for (int ix = 0; ix < node.getNumChildren(); ix++) {
ApexNode<?> sn = node.getChild(ix);
if (sn instanceof ASTParameter) {
numParams++;
}
}
return numParams == 0 && "hashCode".equalsIgnoreCase(node.getImage());
}
}
pmd-apex/src/main/resources/category/apex/errorprone.xml
+52 -13
View File
@@ -111,6 +111,30 @@ public without sharing class Foo {
</example>
</rule>
<rule name="AvoidNonExistentAnnotations"
language="apex"
since="6.5.0"
message="Use of non existent annotations will lead to broken Apex code which will not compile in the future."
class="net.sourceforge.pmd.lang.apex.rule.errorprone.AvoidNonExistentAnnotationsRule"
externalInfoUrl="${pmd.website.baseurl}/pmd_rules_apex_errorprone.html#avoidnonexistentannotations">
<description>
Apex supported non existent annotations for legacy reasons.
In the future, use of such non-existent annotations could result in broken apex code that will not compile.
This will prevent users of garbage annotations from being able to use legitimate annotations added to Apex in the future.
A full list of supported annotations can be found at https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_classes_annotation.htm
</description>
<priority>3</priority>
<example>
<![CDATA[
@NonExistentAnnotation public class ClassWithNonexistentAnnotation {
@NonExistentAnnotation public void methodWithNonExistentAnnotation() {
// ...
}
}
]]>
</example>
</rule>
<rule name="EmptyCatchBlock"
language="apex"
since="6.0.0"
@@ -317,24 +341,39 @@ public class MyClass {
</example>
</rule>
<rule name="AvoidNonExistentAnnotations"
<rule name="OverrideBothEqualsAndHashcode"
language="apex"
since="6.5.0"
message="Use of non existent annotations will lead to broken Apex code which will not compile in the future."
class="net.sourceforge.pmd.lang.apex.rule.errorprone.AvoidNonExistentAnnotationsRule"
externalInfoUrl="${pmd.website.baseurl}/pmd_rules_apex_errorprone.html#avoidnonexistentannotations">
since="6.31.0"
message="Ensure you override both equals() and hashCode()"
class="net.sourceforge.pmd.lang.apex.rule.errorprone.OverrideBothEqualsAndHashcodeRule"
externalInfoUrl="${pmd.website.baseurl}/pmd_rules_apex_errorprone.html#overridebothequalsandhashcode">
<description>
Apex supported non existent annotations for legacy reasons.
In the future, use of such non-existent annotations could result in broken apex code that will not compile.
This will prevent users of garbage annotations from being able to use legitimate annotations added to Apex in the future.
A full list of supported annotations can be found at https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_classes_annotation.htm
Override both `public Boolean equals(Object obj)`, and `public Integer hashCode()`, or override neither.
Even if you are inheriting a hashCode() from a parent class, consider implementing hashCode and explicitly
delegating to your superclass.
This is especially important when [Using Custom Types in Map Keys and Sets](https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/langCon_apex_collections_maps_keys_userdefined.htm).
</description>
<priority>3</priority>
<example>
<![CDATA[@NonExistentAnnotation public class ClassWithNonexistentAnnotation {
@NonExistentAnnotation public void methodWithNonExistentAnnotation() {
// ...
}
<![CDATA[
public class Bar { // poor, missing a hashCode() method
public Boolean equals(Object o) {
// do some comparison
}
}
public class Baz { // poor, missing an equals() method
public Integer hashCode() {
// return some hash value
}
}
public class Foo { // perfect, both methods provided
public Boolean equals(Object other) {
// do some comparison
}
public Integer hashCode() {
// return some hash value
}
}
]]>
</example>
pmd-apex/src/main/resources/rulesets/apex/quickstart.xml
+1
View File
@@ -472,5 +472,6 @@
</properties>
</rule>
<!-- <rule ref="category/apex/bestpractices.xml/UnusedLocalVariable"/> -->
<!-- <rule ref="category/apex/errorprone.xml/OverrideBothEqualsAndHashcode" /> -->
</ruleset>
pmd-apex/src/test/java/net/sourceforge/pmd/lang/apex/rule/errorprone/OverrideBothEqualsAndHashcodeTest.java
+11
View File
@@ -0,0 +1,11 @@
/**
* BSD-style license; for more info see http://pmd.sourceforge.net/license.html
*/
package net.sourceforge.pmd.lang.apex.rule.errorprone;
import net.sourceforge.pmd.testframework.PmdRuleTst;
public class OverrideBothEqualsAndHashcodeTest extends PmdRuleTst {
// no additional unit tests
}
pmd-apex/src/test/resources/net/sourceforge/pmd/lang/apex/rule/errorprone/xml/OverrideBothEqualsAndHashcode.xml
+166
View File
@@ -0,0 +1,166 @@
<?xml version="1.0" encoding="UTF-8"?>
<test-data
xmlns="http://pmd.sourceforge.net/rule-tests"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://pmd.sourceforge.net/rule-tests http://pmd.sourceforge.net/rule-tests_1_0_0.xsd">
<test-code>
<description>hash code only</description>
<expected-problems>1</expected-problems>
<code><![CDATA[
public class Foo {
public Integer hashCode() {}
}
]]></code>
</test-code>
<test-code>
<description>nested hash code only</description>
<expected-problems>1</expected-problems>
<code><![CDATA[
public class Foo {
public class Bar {
public Integer hashCode() {}
}
}
]]></code>
</test-code>
<test-code>
<description>equals only</description>
<expected-problems>1</expected-problems>
<code><![CDATA[
public class Foo {
public boolean equals(Object other) {}
}
]]></code>
</test-code>
<test-code>
<description>nested equals only, checking case insensitiveness</description>
<expected-problems>1</expected-problems>
<code><![CDATA[
public class Foo {
public class Bar {
public Integer eQuAlS(Object other) {}
}
}
]]></code>
</test-code>
<test-code>
<description>overrides both</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public class Foo {
public boolean equals(Object other) {}
public Integer hashCode() {}
}
]]></code>
</test-code>
<test-code>
<description>nested overrides both</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public class Foo {
public class Bar {
public boolean equals(Object other) {}
public Integer hashCode() {}
}
}
]]></code>
</test-code>
<test-code>
<description>overrides neither</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public class Foo {}
]]></code>
</test-code>
<test-code>
<description>equals sig uses String, not Object</description>
<expected-problems>1</expected-problems>
<code><![CDATA[
public class Foo {
public boolean equals(String o) {
return true;
}
public Integer hashCode() {
return 0;
}
}
]]></code>
</test-code>
<test-code>
<description>interface</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public interface Foo {
boolean equals(Object o);
}
]]></code>
</test-code>
<test-code>
<description>implements equals but with 2 args, hashCode overloaded as well</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public class Foo {
public boolean equals(java.lang.Object o1, java.lang.Object o2) {
return true;
}
public Integer hashCode(java.lang.Object o) {
return 0;
}
}
]]></code>
</test-code>
<test-code>
<description>overloaded hashCode</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public class Foo {
public Integer hashCode(Object o1) { return false; }
}
]]></code>
</test-code>
<test-code>
<description>overloaded both</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public class Foo {
public boolean equals(Object o1, Object o2) { return false; }
public Integer hashCode(Object o1) { return false; }
}
]]></code>
</test-code>
<test-code>
<description>overloaded hashCode, should fail on equals</description>
<expected-problems>1</expected-problems>
<code><![CDATA[
public class Foo {
public boolean equals(Object o1) { return false; }
public Integer hashCode(Object o1) { return false; }
}
]]></code>
</test-code>
<test-code>
<description>implements hashCode but with args</description>
<expected-problems>0</expected-problems>
<code><![CDATA[
public class Foo {
public Integer hashCode(List<Decimal> a) {
return 0;
}
}
]]></code>
</test-code>
</test-data>
pmd-core/src/main/resources/rulesets/releases/6310.xml
+13
View File
@@ -0,0 +1,13 @@
<?xml version="1.0"?>
<ruleset name="6310"
xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">
<description>
This ruleset contains links to rules that are new in PMD v6.31.0
</description>
<rule ref="category/apex/errorprone.xml/OverrideBothEqualsAndHashcode" />
</ruleset>