[apex] Cannot load ruleset for custom rule ExcessiveClassLength

[aruntyagiTutu]

Affects PMD Version:

PMD 7.0.0

Description:

Method List loadRuleSetsWithoutException(List rulesetPaths) is throwing expection for custom ruleset xml for depricated rule (ex: ExcessiveClassLength), earlier versions were supposed to throw a warning not excpetion.

Exception Stacktrace:

"Cannot load ruleset /var/folders/4n/_s0xwt010hd08x07cjfcy1mc0000gn/T/junit-15737253256320483705/excessive-classlength.xml: PMD threw an unexpected exception:
Warning at /var/folders/4n/_s0xwt010hd08x07cjfcy1mc0000gn/T/junit-15737253256320483705/excessive-classlength.xml:7:5
 5|     <description>Sample Custom PMD Rules Description</description>
 6|     <rule ref="category/apex/design.xml"/>
 7|     <rule ref="category/apex/design.xml/ExcessiveClassLength">
        ^^^^^ Discontinue using Rule name category/apex/design.xml/ExcessiveClassLength as it is scheduled for removal from PMD. PMD 8.0.0 will remove support for this Rule.

 8|       <properties>
 9|         <property name="minimum" value="100"/>"

Code Sample demonstrating the issue:

    @Test
    void whenDescribeRulesIsGivenCustomRulesetThatOverridesExcessiveClassLength_thenCustomWins(@TempDir Path tempDir) throws Exception {
        String xml = """
            <?xml version="1.0" encoding="UTF-8"?>
            <ruleset name="Custom PMD Rules"
                     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 http://pmd.sourceforge.net/ruleset_2_0_0.xsd">
              <description>Custom PMD rules for Code Analyzer</description>
              <rule ref="category/apex/design.xml"/>
              <rule ref="category/apex/design.xml/ExcessiveClassLength">
                <properties>
                  <property name="minimum" value="100"/>
                </properties>
              </rule>
            </ruleset>
            """;
        Path rulesetFile = tempDir.resolve("excessive-classlength.xml");
        Files.writeString(rulesetFile, xml);

        List<PmdRuleInfo> ruleInfoList = ruleDescriber.describeRulesFor(
                List.of(rulesetFile.toAbsolutePath().toString()),
                Set.of("apex"));

        PmdRuleInfo ruleInfo = assertContainsOneRuleWithNameAndLanguage(ruleInfoList, "ExcessiveClassLength", "apex");
        assertThat(ruleInfo.ruleSetFile, is(rulesetFile.toAbsolutePath().toString()));
        assertThat(ruleInfo.ruleSets, hasItems("Custom PMD Rules", "Design"));
        assertThat(ruleInfo.externalInfoUrl, allOf(startsWith("https://"), endsWith(".html#excessiveclasslength")));
    }

Steps to reproduce:

Please provide detailed steps for how we can reproduce the bug.

1. for custom pmd.xml with depecricated apex rule engine is throwing error
2. ...

Running PMD through: [Gradle]

[adangel]

Thanks for reporting. However, I can't reproduce the problem.

I've created a small test project here, but I only get a warning and no exception, when I load the ruleset. This is the correct behavior. See https://github.com/adangel/scratchpad/blob/master/pmd-issue-6395/src/test/java/net/sourceforge/pmd/it/issue6395deprecatedrules/RuleSetLoaderTest.java

earlier versions were supposed to throw a warning not excpetion.

Note: only exceptions can be thrown, warnings cannot. Warnings are logged.

I don't know the class PmdRuleInfo or the ruleDescriber. Can you give more info, where these classes are coming from?

[aruntyagiTutu]

Here is a java testcase which can help you repro

@Test
    void whenCallingMainWithDescribeWithDeprecatedExcessiveClassLengthRuleset_thenRuleAppearsInDescribe(@TempDir Path tempDir) throws Exception {
        // Create a minimal ruleset that references Apex ExcessiveClassLength (design)
        String rulesetXml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
                "<ruleset name=\"Ruleset for ExcessiveClassLength\"\n" +
                "    xmlns=\"http://pmd.sourceforge.net/ruleset/2.0.0\"\n" +
                "    xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n" +
                "    xsi:schemaLocation=\"http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd\">\n" +
                "    <description>Include Apex ExcessiveClassLength</description>\n" +
                "    <rule ref=\"category/apex/design.xml/ExcessiveClassLength\" />\n" +"    <rule ref=\"category/apex/design.xml/NcssCount\" />\n" +
                "</ruleset>";
        Path excessiveClassLengthRuleset = tempDir.resolve("excessive-class-length-ruleset.xml");
        Files.write(excessiveClassLengthRuleset, rulesetXml.getBytes());

        // Prepare describe args with a custom rulesets list file
        Path outputFile = tempDir.resolve("describe-output.json");
        Path rulesetsList = tempDir.resolve("customRulesetsList.txt");
        Files.write(rulesetsList, (excessiveClassLengthRuleset.toAbsolutePath().toString() + "\n").getBytes());

        String[] args = {"describe", outputFile.toAbsolutePath().toString(),
                rulesetsList.toAbsolutePath().toString(), "apex"};
        callPmdWrapper(args);

        // Parse output and assert ExcessiveClassLength is present and references our ruleset file
        String fileContents = Files.readString(outputFile);
        Gson gson = new Gson();
        Type pmdRuleInfoListType = new TypeToken<List<PmdRuleInfo>>(){}.getType();
        List<PmdRuleInfo> pmdRuleInfoList = gson.fromJson(fileContents, pmdRuleInfoListType);
        PmdRuleInfo ruleInfo = assertContainsOneRuleWithNameAndLanguage(pmdRuleInfoList, "ExcessiveClassLength", "apex");
        assertThat(ruleInfo.ruleSetFile, is(excessiveClassLengthRuleset.toAbsolutePath().toString()));
    }

where it is failing - Class RuleSetFactory.class

 if (warnDeprecated && referencedRule.isDeprecated()) {
            if (referencedRule instanceof RuleReference) {

in case of deprecated rule excessiveClassLength referencedRule is not instanceof RuleReference
that is why it is throwing error

err.at(ruleNode).warn(
                    "Discontinue using Rule name {0} as it is scheduled for removal from PMD."
                        + " PMD {1} will remove support for this Rule.",
                    otherRuleSetReferenceId, PMDVersion.getNextMajorRelease());

[adangel]

Can you show me your code for callPmdWrapper?

[aruntyagiTutu]

thank you for the response @adangel
here is callwrapper code

private static String callPmdWrapper(String[] args) {
        try (StdOutCaptor stdoutCaptor = new StdOutCaptor()) {
            PmdWrapper.main(args);
            return stdoutCaptor.getCapturedOutput();
        }
    }

[adangel]

After searching github for PmdWrapper I finally found the project you are trying to fix: It's https://github.com/forcedotcom/code-analyzer-core

More specifically, here are the implementations your are testing with your unit test:

• https://github.com/forcedotcom/code-analyzer-core/blob/dev/packages/code-analyzer-pmd-engine/pmd-cpd-wrappers/src/main/java/com/salesforce/sfca/pmdwrapper/PmdWrapper.java
• https://github.com/forcedotcom/code-analyzer-core/blob/dev/packages/code-analyzer-pmd-engine/pmd-cpd-wrappers/src/main/java/com/salesforce/sfca/pmdwrapper/PmdRuleDescriber.java

The problem is, that the PmdErrorListener throws exceptions instead of logging them, e.g.
https://github.com/forcedotcom/code-analyzer-core/blob/db8332951c9fdf8a616563669db3ee0a28adb6dd/packages/code-analyzer-pmd-engine/pmd-cpd-wrappers/src/main/java/com/salesforce/sfca/pmdwrapper/PmdRuleDescriber.java#L173

throw new RuntimeException("PMD threw an unexpected exception:\n" + message);

From my point of few, there is a bug in this PmdErrorListener, that it should not throw an exception if it is just a warning. This can be fixed by adding the following lines:

                         }
                     }
                     throw new RuntimeException("PMD threw an unexpected exception:\n" + message, throwable);
+                } else if (level == Level.WARN && s != null) {
+                    System.out.println("[Warn] " + s);
                 } else if (s != null) {
                     String message = MessageFormat.format(s, objects);
                     throw new RuntimeException("PMD threw an unexpected exception:\n" + message);
                 }

If the exception is thrown there, then this RuntimeException is rethrown by PMD as a RuleSetLoadException (see

pmd/pmd-core/src/main/java/net/sourceforge/pmd/lang/rule/RuleSetLoader.java

Line 252 in cdf317f

throw new RuleSetLoadException(ruleSetReferenceId, e);

) which in turn is then again caught by this PmdErrorListener and rethrown again ...

I now also found your PR -> forcedotcom/code-analyzer-core#403

But I think, this is a bug in PmdRuleDescriber.PmdErrorListener. It appears to be that case since 2 years... @stephen-carter-at-sf Wdyt?

[aruntyagiTutu]

thanks @adangel , this is helpful.