Add dependency-graph-file as step output

Fixes #804

.github/workflows/integ-test-dependency-graph.yml

@@ -78,20 +78,18 @@ jobs:
       uses: ./
       with:
         dependency-graph: generate
-    - name: Run assemble
+    - id: gradle-assemble
       run: ./gradlew assemble
       working-directory: .github/workflow-samples/groovy-dsl
-      env:
+    - id: gradle-build
-        GITHUB_JOB_CORRELATOR: job-correlator
-    - name: Run build
       run: ./gradlew build
       working-directory: .github/workflow-samples/groovy-dsl
-      env:
-        GITHUB_JOB_CORRELATOR: job-correlator
     - name: Check generated dependency graphs
       run: |
+        echo "gradle-assemble report file: ${{ steps.gradle-assemble.outputs.dependency-graph-file }}"
+        echo "gradle-build report file: ${{ steps.gradle-build.outputs.dependency-graph-file }}"
         ls -l dependency-graph-reports
-        if ([ ! -e dependency-graph-reports/job-correlator.json ] || [ ! -e dependency-graph-reports/job-correlator-1.json ])
+        if ([ ! -e ${{ steps.gradle-assemble.outputs.dependency-graph-file }} ] || [ ! -e ${{ steps.gradle-build.outputs.dependency-graph-file }} ])
         then
             echo "Did not find expected dependency graph files"
             exit 1

src/resources/init-scripts/github-dependency-graph.init.gradle

@@ -15,14 +15,20 @@ if (GradleVersion.current().baseVersion < GradleVersion.version("5.0")) {
 // This is only required for top-level builds
 def isTopLevelBuild = gradle.getParent() == null
 if (isTopLevelBuild) {
-  def jobCorrelator = ensureUniqueJobCorrelator(System.env.GITHUB_JOB_CORRELATOR)
+  def reportFile = getUniqueReportFile(System.env.GITHUB_JOB_CORRELATOR)
 
-  if (jobCorrelator == null) {
+  if (reportFile == null) {
-    println "::warning::No dependency snapshot generated for step: report file for '${jobCorrelator}' created in earlier step. Each build invocation requires a unique job correlator: specify GITHUB_JOB_CORRELATOR var for this step."
+    println "::warning::No dependency snapshot generated for step. Could not determine unique job correlator - specify GITHUB_JOB_CORRELATOR var for this step."
     return
   }
 
-  println "Generating dependency graph for '${jobCorrelator}'"
+  def githubOutput = System.getenv("GITHUB_OUTPUT")
+  if (githubOutput) {
+      new File(githubOutput) << "dependency-graph-file=${reportFile.absolutePath}\n"
+  }
+
+
+  println "Generating dependency graph into '${reportFile}'"
 }
 
 apply from: 'github-dependency-graph-gradle-plugin-apply.groovy'
@@ -33,10 +39,10 @@ apply from: 'github-dependency-graph-gradle-plugin-apply.groovy'
  * - If so, tries to find a unique value that does not yet have a corresponding report file.
  * - When found, this value is set as a System property override.
  */
-String ensureUniqueJobCorrelator(String jobCorrelator) {
+File getUniqueReportFile(String jobCorrelator) {
     def reportDir = System.env.DEPENDENCY_GRAPH_REPORT_DIR
     def reportFile = new File(reportDir, jobCorrelator + ".json")
-    if (!reportFile.exists()) return jobCorrelator
+    if (!reportFile.exists()) return reportFile
 
     // Try at most 100 suffixes
     for (int i = 1; i < 100; i++) {
@@ -44,7 +50,7 @@ String ensureUniqueJobCorrelator(String jobCorrelator) {
         def candidateFile = new File(reportDir, candidateCorrelator + ".json")
         if (!candidateFile.exists()) {
            System.properties['GITHUB_JOB_CORRELATOR'] = candidateCorrelator
-           return candidateCorrelator
+           return candidateFile
         }
     }
 

test/init-scripts/src/test/groovy/com/gradle/gradlebuildaction/TestDependencyGraph.groovy

@@ -29,9 +29,10 @@ class TestDependencyGraph extends BaseInitScriptTest {
 
         then:
         assert reportFile.exists()
+        assert gitHubOutputFile.text == "dependency-graph-file=${reportFile.absolutePath}\n"
 
         where:
-        testGradleVersion << DEPENDENCY_GRAPH_VERSIONS
+        testGradleVersion << GRADLE_8_X
     }
 
     // Dependency-graph plugin doesn't support config-cache for 8.0 of Gradle
@@ -114,7 +115,8 @@ class TestDependencyGraph extends BaseInitScriptTest {
             GITHUB_REF: "main",
             GITHUB_SHA: "123456",
             GITHUB_WORKSPACE: testProjectDir.absolutePath,
-            DEPENDENCY_GRAPH_REPORT_DIR: reportsDir.absolutePath
+            DEPENDENCY_GRAPH_REPORT_DIR: reportsDir.absolutePath,
+            GITHUB_OUTPUT: gitHubOutputFile.absolutePath
         ]
     }
 
@@ -125,4 +127,8 @@ class TestDependencyGraph extends BaseInitScriptTest {
     def getReportFile() {
         return new File(reportsDir, "CORRELATOR.json")
     }
+
+    def getGitHubOutputFile() {
+        return new File(testProjectDir, "GITHUB_OUTPUT")
+    }
 }