Only write dependency-graph on build success

Fixes #115

plugin-test/src/test/groovy/org/gradle/github/dependencygraph/BaseExtractorTest.groovy

@@ -99,6 +99,16 @@ abstract class BaseExtractorTest extends Specification {
         return result
     }
 
+    protected BuildResult runAndFail() {
+        return runAndFail("ForceDependencyResolutionPlugin_resolveAllDependencies")
+    }
+
+    protected BuildResult runAndFail(String... names) {
+        executer.withTasks(names)
+        result = getExecuter().runWithFailure()
+        return result
+    }
+
     @CompileDynamic
     protected void applyDependencyGraphPlugin() {
         File pluginJar = TEST_CONFIG.asFile("extractorPlugin.jar.path")

plugin-test/src/test/groovy/org/gradle/github/dependencygraph/DependencyExtractorConfigTest.groovy

@@ -52,6 +52,17 @@ class DependencyExtractorConfigTest extends BaseExtractorTest {
         assert job.id == environmentVars.jobId
     }
 
+    def "fails gracefully if configuration values not set"() {
+        when:
+        def envVars = environmentVars.asEnvironmentMap()
+        envVars.remove("GITHUB_DEPENDENCY_GRAPH_JOB_CORRELATOR")
+        executer.withEnvironmentVars(envVars)
+        def result = executer.runWithFailure()
+
+        then:
+        result.output.contains("> The configuration parameter 'GITHUB_DEPENDENCY_GRAPH_JOB_CORRELATOR' must be set")
+    }
+
     @IgnoreIf({
         // There is an issue where BuildService is closed too early in Gradle 8.0,
         // resulting in empty dependency graph.
@@ -88,14 +99,38 @@ class DependencyExtractorConfigTest extends BaseExtractorTest {
         !dependencyGraphFile.exists()
     }
 
-    def "fails gracefully if configuration values not set"() {
+    def "does not generate dependency-graph on configuration failure"() {
+        given:
+        buildFile << """
+        throw new RuntimeException("Failure during configuration")
+        """
+
         when:
-        def envVars = environmentVars.asEnvironmentMap()
-        envVars.remove("GITHUB_DEPENDENCY_GRAPH_JOB_CORRELATOR")
-        executer.withEnvironmentVars(envVars)
-        def result = executer.runWithFailure()
+        def buildResult = runAndFail()
 
         then:
-        result.output.contains("> The configuration parameter 'GITHUB_DEPENDENCY_GRAPH_JOB_CORRELATOR' must be set")
+        buildResult.output.contains("Gradle Build did not complete successfully: Dependency Graph file will not be generated.")
+        !dependencyGraphFile.exists()
+    }
+
+    def "does not generate dependency-graph on task failure"() {
+        given:
+        buildFile << """
+            tasks.register("taskThatSucceeds") {
+              doLast {}
+            }
+            tasks.register("taskThatFails") {
+              doLast {
+                throw new RuntimeException("Failure in task")
+              }
+            }
+        """
+
+        when:
+        def buildResult = runAndFail("taskThatSucceeds", "taskThatFails")
+
+        then:
+        buildResult.output.contains("Gradle Build did not complete successfully: Dependency Graph file will not be generated.")
+        !dependencyGraphFile.exists()
     }
 }

plugin/src/main/kotlin/org/gradle/dependencygraph/extractor/DependencyExtractor.kt

@@ -10,7 +10,8 @@ import org.gradle.api.logging.Logging
 import org.gradle.dependencygraph.DependencyGraphRenderer
 import org.gradle.dependencygraph.model.*
 import org.gradle.dependencygraph.model.DependencyScope.*
-import org.gradle.dependencygraph.util.*
+import org.gradle.dependencygraph.util.PluginParameters
+import org.gradle.execution.RunRootBuildWorkBuildOperationType
 import org.gradle.initialization.EvaluateSettingsBuildOperationType
 import org.gradle.initialization.LoadProjectsBuildOperationType
 import org.gradle.internal.exceptions.DefaultMultiCauseException
@@ -38,6 +39,8 @@ abstract class DependencyExtractor :
     private val pluginParameters = PluginParameters()
 
     private var settingsEvaluated = false
+    private var buildWorkCompleted = false
+    private var buildWorkFailure = false
 
     private val resolvedConfigurations = Collections.synchronizedList(mutableListOf<ResolvedConfiguration>())
 
@@ -60,6 +63,7 @@ abstract class DependencyExtractor :
     abstract fun getRendererClassName(): String
 
     override fun started(buildOperation: BuildOperationDescriptor, startEvent: OperationStartEvent) {
+        println("Got started operation: $buildOperation --- $startEvent")
         // This method will never be called when registered in a `BuildServiceRegistry` (i.e. Gradle 6.1 & higher)
         // No-op
     }
@@ -70,6 +74,7 @@ abstract class DependencyExtractor :
     }
 
     override fun finished(buildOperation: BuildOperationDescriptor, finishEvent: OperationFinishEvent) {
+
         handleBuildOperationType<
             ResolveConfigurationDependenciesBuildOperationType.Details,
             ResolveConfigurationDependenciesBuildOperationType.Result
@@ -82,6 +87,10 @@ abstract class DependencyExtractor :
         handleBuildOperationType<
             EvaluateSettingsBuildOperationType.Details,
             EvaluateSettingsBuildOperationType.Result>(buildOperation, finishEvent) { details, _ -> extractSettings(details) }
+
+        if (buildOperation.details is RunRootBuildWorkBuildOperationType.Details) {
+            handleRunWorkCompleted(finishEvent)
+        }
     }
 
     private inline fun <reified D, reified R> handleBuildOperationType(
@@ -341,6 +350,13 @@ abstract class DependencyExtractor :
         )
     }
 
+    private fun handleRunWorkCompleted(finishEvent: OperationFinishEvent) {
+        buildWorkCompleted = true
+        if (finishEvent.failure != null) {
+            buildWorkFailure = true
+        }
+    }
+
     override fun close() {
         if (thrownExceptions.isNotEmpty()) {
             throw DefaultMultiCauseException(
@@ -358,6 +374,13 @@ abstract class DependencyExtractor :
             )
             return
         }
+        // We use the absence of Settings Evaluated to determine if the build was loaded from the configuration-cache
+        if (!buildWorkCompleted || buildWorkFailure) {
+            LOGGER.lifecycle(
+                "Gradle Build did not complete successfully: Dependency Graph file will not be generated."
+            )
+            return
+        }
         try {
             writeDependencyGraph()
         } catch (e: RuntimeException) {