Add more tests for pmd incremental analysis

subprojects/code-quality/src/integTest/groovy/org/gradle/api/plugins/quality/PmdPluginIncrementalAnalysisIntegrationTest.groovy

@@ -16,7 +16,13 @@
 package org.gradle.api.plugins.quality
 
 import org.gradle.integtests.fixtures.AbstractIntegrationSpec
+import org.gradle.util.Matchers
 import org.gradle.util.TestPrecondition
+import org.gradle.util.VersionNumber
+
+import static org.gradle.util.Matchers.containsLine
+import static org.hamcrest.Matchers.containsString
+import static org.hamcrest.Matchers.not
 
 class PmdPluginIncrementalAnalysisIntegrationTest extends AbstractIntegrationSpec {
     def setup() {
@@ -39,22 +45,122 @@ class PmdPluginIncrementalAnalysisIntegrationTest extends AbstractIntegrationSpe
     }
 
     def "incremental analysis can be enabled"() {
+        given:
         goodCode()
-        buildFile << '''
-        pmd {
-            incrementalAnalysis = true
-        }
-'''
+        buildFile << 'pmd { incrementalAnalysis = true }'
 
-        expect:
-        succeeds("check")
+        when:
+        args('--info')
+        succeeds("pmdMain")
         file("build/pmd-cache/pmdMain.cache").exists()
+
+        then:
+        output.contains('Analysis cache invalidated, rulesets changed')
+
+        when:
+        args('--rerun-tasks', '--info')
+        succeeds("pmdMain")
+
+        then:
+        !output.contains('Analysis cache invalidated, rulesets changed')
+    }
+
+    def 'incremental analysis is transparent'() {
+        given:
+        buildFile << 'pmd { incrementalAnalysis = true }'
+        goodCode()
+        badCode()
+
+        when:
+        fails('pmdMain')
+
+        then:
+        file("build/reports/pmd/main.xml").assertContents(Matchers.containsText('BadClass'))
+
+        when:
+        file('src/main/java/org/gradle/BadClass.java').delete()
+        succeeds('pmdMain')
+
+        then:
+        file("build/reports/pmd/main.xml").
+            assertContents(not(containsLine(containsString('BadClass'))))
+    }
+
+    def 'incremental analysis invalidated when #reason'() {
+        given:
+        goodCode()
+        customRuleSet()
+        buildFile << 'pmd { incrementalAnalysis = true }'
+
+        when:
+        succeeds('pmdMain')
+        buildFile << "\npmd{${code}}"
+        succeeds('pmdMain', '--info')
+
+        then:
+        outputContains("Analysis cache invalidated, ${reason}")
+
+
+        where:
+        reason                | code
+        'PMD version changed' | 'toolVersion="5.8.0"'
+        'rulesets changed'    | 'ruleSetFiles = files("customRuleSet.xml")'
+    }
+
+    def "incremental analysis is available in 5.6.0+"() {
+        given:
+        buildFile << """
+pmd { 
+    incrementalAnalysis = true
+    toolVersion = '${version}'
+}    
+"""
+        goodCode()
+
+        when:
+        supportIncrementalAnalysis(version) ? succeeds('pmdMain') : fails('pmdMain')
+
+        then:
+        supportIncrementalAnalysis(version) ? failure == null : failure.error.contains('Incremental analysis only supports Pmd 5.6.0+')
+
+        where:
+        _ | version
+        _ | '4.3'
+        _ | '5.0.5'
+        _ | '5.1.1'
+        _ | '5.3.3'
+        _ | '5.6.0'
+        _ | PmdPlugin.DEFAULT_PMD_VERSION
+    }
+
+    private supportIncrementalAnalysis(String version) {
+        return VersionNumber.parse(version) >= VersionNumber.parse('5.6.0')
     }
 
     private goodCode() {
-        file("src/main/java/org/gradle/Class1.java") <<
-            "package org.gradle; class Class1 { public boolean isFoo(Object arg) { return true; } }"
-        file("src/test/java/org/gradle/Class1Test.java") <<
-            "package org.gradle; class Class1Test { public boolean isFoo(Object arg) { return true; } }"
+        file("src/main/java/org/gradle/GoodClass.java") <<
+            "package org.gradle; class GoodClass { public boolean isFoo(Object arg) { return true; } }"
+    }
+
+    private badCode() {
+        // PMD Lvl 2 Warning BooleanInstantiation
+        // PMD Lvl 3 Warning OverrideBothEqualsAndHashcode
+        file("src/main/java/org/gradle/BadClass.java") <<
+            "package org.gradle; class BadClass { public boolean equals(Object arg) { return java.lang.Boolean.valueOf(true); } }"
+    }
+
+    private customRuleSet() {
+        file("customRuleSet.xml") << """
+            <ruleset name="custom"
+                xmlns="http://pmd.sf.net/ruleset/1.0.0"
+                xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+                xsi:schemaLocation="http://pmd.sf.net/ruleset/1.0.0 http://pmd.sf.net/ruleset_xml_schema.xsd"
+                xsi:noNamespaceSchemaLocation="http://pmd.sf.net/ruleset_xml_schema.xsd">
+
+                <description>Custom rule set</description>
+
+                <rule ref="rulesets/java/braces.xml"/>
+            </ruleset>
+        """
     }
 }

subprojects/code-quality/src/main/groovy/org/gradle/api/plugins/quality/PmdExtension.java

@@ -198,7 +198,7 @@ public void setConsoleOutput(boolean consoleOutput) {
     /**
      * Retrieves wether to use incremental analysis or not.
      *
-     * This is only supported for PMD 5.6.0 or better.
+     * This is only supported for PMD 5.6.0 or better. See <a href="https://pmd.github.io/pmd-5.6.0/overview/changelog.html#Incremental_Analysis"></a> for more details.
      *
      * @since 4.3
      */
@@ -210,7 +210,7 @@ public boolean isIncrementalAnalysis() {
     /**
      * Configures wether to use incremental analysis or not.
      *
-     * This is only supported for PMD 5.6.0 or better.
+     * This is only supported for PMD 5.6.0 or better.See <a href="https://pmd.github.io/pmd-5.6.0/overview/changelog.html#Incremental_Analysis"></a> for more details.
      *
      * @param incrementalAnalysis True to enable incremental analysis.
      *

subprojects/code-quality/src/main/groovy/org/gradle/api/plugins/quality/internal/PmdInvoker.groovy

@@ -51,23 +51,29 @@ abstract class PmdInvoker {
         def postPmd56 = pmdVersion >= VersionNumber.parse('5.6.0')
 
         def antPmdArgs = [failOnRuleViolation: false, failuresPropertyName: "pmdFailureCount"]
-        if (prePmd5) {
-            // NOTE: PMD 5.0.2 apparently introduces an element called "language" that serves the same purpose
-            // http://sourceforge.net/p/pmd/bugs/1004/
-            // http://java-pmd.30631.n5.nabble.com/pmd-pmd-db05bc-pmd-AntTask-support-for-language-td5710041.html
-            antPmdArgs["targetjdk"] = targetJdk.name
 
-            // fallback to basic on pre 5.0 for backwards compatible
-            if (ruleSets == ["java-basic"]) {
-                ruleSets = ['basic']
-                pmdTask.setRuleSets(ruleSets)
-            }
-        } else if (postPmd56) {
+        if (postPmd56) {
             // PMD 5.6.0 added an incremental analysis cache
             // https://pmd.github.io/pmd-5.7.0/overview/changelog-old.html#Incremental_Analysis
             if (incrementalAnalysis) {
                 antPmdArgs["cacheLocation"] = new File(buildDir.path + "/pmd-cache", taskName + ".cache")
             }
+        } else {
+            if(incrementalAnalysis){
+                throw new GradleException("Incremental analysis only supports Pmd 5.6.0+")
+            }
+            if (prePmd5) {
+                // NOTE: PMD 5.0.2 apparently introduces an element called "language" that serves the same purpose
+                // http://sourceforge.net/p/pmd/bugs/1004/
+                // http://java-pmd.30631.n5.nabble.com/pmd-pmd-db05bc-pmd-AntTask-support-for-language-td5710041.html
+                antPmdArgs["targetjdk"] = targetJdk.name
+
+                // fallback to basic on pre 5.0 for backwards compatible
+                if (ruleSets == ["java-basic"]) {
+                    ruleSets = ['basic']
+                    pmdTask.setRuleSets(ruleSets)
+                }
+            }
         }
 
         antPmdArgs["minimumPriority"] = rulePriority