Restrict Gradle integration tests locally

The full set of integration tests with several
Gradle versions will only be executed in CI (GH Action).
Locally only the latest version is checked
to improve test throughput
while still checking that
the test cases are working.

htmlSanityCheck-gradle-plugin/README.adoc

@@ -321,12 +321,24 @@ htmlSanityCheck {
 
 The Plugin has been tested with the following Gradle versions:
 
-[source]
+[source,groovy]
 .Tested Gradle versions
 ----
 include::src/test/groovy/org/aim42/htmlsanitycheck/gradle/HtmlSanityCheckTaskFunctionalSpec.groovy[tag=tested-gradle-versions,indent=0]
 ----
 
+[NOTE]
+====
+The full range of Gradle versions is only tested in CI (GitHub action).
+The local test only tests the latest Gradle version:
+
+[source,groovy]
+.Restricting versions to the latest versions locally
+----
+include::src/test/groovy/org/aim42/htmlsanitycheck/gradle/HtmlSanityCheckTaskFunctionalSpec.groovy[tag=restrict-gradle-versions-locally,indent=0]
+----
+====
+
 [[sec:development-versions]]
 == Development versions
 

htmlSanityCheck-gradle-plugin/src/test/groovy/org/aim42/htmlsanitycheck/gradle/HtmlSanityCheckTaskFunctionalSpec.groovy

@@ -4,18 +4,37 @@ package org.aim42.htmlsanitycheck.gradle
 import org.gradle.testkit.runner.GradleRunner
 import org.jsoup.Jsoup
 import org.jsoup.nodes.Element
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
 import spock.lang.Unroll
 
 import static org.gradle.testkit.runner.TaskOutcome.FAILED
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
 class HtmlSanityCheckTaskFunctionalSpec extends HtmlSanityCheckBaseSpec {
-    private final static GRADLE_VERSIONS = [ // 6.x or older does not work!
-                                             '7.6.3', // latest 7.x
-                                             '8.0.2', '8.1.1', '8.2.1', '8.3', '8.4',
-                                             '8.5', '8.6', '8.7', '8.8', '8.9',
-                                             '8.10.1' // all 8.x (latest patches)
-    ]
+
+    // @Slf4j does not initialize logger for static initializer
+    private static final Logger log = LoggerFactory.getLogger(HtmlSanityCheckTaskFunctionalSpec)
+
+    private final static List<String> getVersions(List<String> versions) {
+        // tag::restrict-gradle-versions-locally[]
+        def result = System.getenv("GITHUB_ACTION") ? versions : [versions[-1]]
+        // end::restrict-gradle-versions-locally[]
+        log.warn("Testing HSC Gradle plugin with versions '{}'", result)
+        return result
+    }
+
+    private final static String[] GRADLE_VERSIONS = getVersions([
+            // tag::tested-gradle-versions[]
+            // Test execution in CI will execute all versions.
+            // Local test is restricted to latest version
+            // 6.x or older does not work!
+            '7.6.3', // latest 7.x
+            '8.0.2', '8.1.1', '8.2.1', '8.3', '8.4',
+            '8.5', '8.6', '8.7', '8.8', '8.9',
+            '8.10.1' // all 8.x minor versions (latest patch release)
+            // end::tested-gradle-versions[]
+    ])
 
     @Unroll
     def "can execute htmlSanityCheck task with Gradle version #gradleVersion"() {
@@ -24,7 +43,7 @@ class HtmlSanityCheckTaskFunctionalSpec extends HtmlSanityCheckBaseSpec {
         createBuildFile()
 
         when:
-        def result = runnerForHtmlSanityCheckTask(gradleVersion).build()
+        def result = runnerForHtmlSanityCheckTask(gradleVersion as String).build()
 
         then:
         result.task(":htmlSanityCheck").outcome == SUCCESS
@@ -43,7 +62,7 @@ class HtmlSanityCheckTaskFunctionalSpec extends HtmlSanityCheckBaseSpec {
 
         when:
 
-        def result = runnerForHtmlSanityCheckTask(gradleVersion).buildAndFail()
+        def result = runnerForHtmlSanityCheckTask(gradleVersion as String).buildAndFail()
 
         then:
         result.task(":htmlSanityCheck").outcome == FAILED
@@ -66,7 +85,7 @@ class HtmlSanityCheckTaskFunctionalSpec extends HtmlSanityCheckBaseSpec {
         """)
 
         when:
-        def result = runnerForHtmlSanityCheckTask(gradleVersion).build()
+        def result = runnerForHtmlSanityCheckTask(gradleVersion as String).build()
 
         then:
         result.task(":htmlSanityCheck").outcome == SUCCESS
@@ -84,7 +103,7 @@ class HtmlSanityCheckTaskFunctionalSpec extends HtmlSanityCheckBaseSpec {
         """)
 
         when:
-        runnerForHtmlSanityCheckTask(gradleVersion).build()
+        runnerForHtmlSanityCheckTask(gradleVersion as String).build()
         def htmlReportFile = new File(testProjectDir.root, "build/index.html")
 
         then: