Add new option to clear dependency-graph

When changing workflow names or when changing to the new 'dependency-submission'
action, it can be useful to clear existing dependency graph snapshots from previous
submissions. While the old graphs will eventually "age out", the 'clear' option will
submit an empty dependency graph for an existing Job correlator, ensuring that old
dependency graphs don't linger.

action.yml

@@ -69,7 +69,7 @@ inputs:
     default: true
 
   dependency-graph:
-    description: Specifies if a GitHub dependency snapshot should be generated for each Gradle build, and if so, how. Valid values are 'disabled' (default), 'generate', 'generate-and-submit' and 'download-and-submit'.
+    description: Specifies if a GitHub dependency snapshot should be generated for each Gradle build, and if so, how. Valid values are 'disabled' (default), 'generate', 'generate-and-submit', 'download-and-submit' and 'clear'.
     required: false
     default: 'disabled'
 

src/dependency-graph.ts

@@ -36,6 +36,12 @@ export async function setup(option: DependencyGraphOption): Promise<void> {
         'DEPENDENCY_GRAPH_REPORT_DIR',
         path.resolve(layout.workspaceDirectory(), 'dependency-graph-reports')
     )
+
+    // To clear the dependency graph, we generate an empty graph by excluding all projects and configurations
+    if (option === DependencyGraphOption.Clear) {
+        core.exportVariable('DEPENDENCY_GRAPH_INCLUDE_PROJECTS', '')
+        core.exportVariable('DEPENDENCY_GRAPH_INCLUDE_CONFIGURATIONS', '')
+    }
 }
 
 export async function complete(option: DependencyGraphOption): Promise<void> {
@@ -47,6 +53,7 @@ export async function complete(option: DependencyGraphOption): Promise<void> {
             await uploadDependencyGraphs()
             return
         case DependencyGraphOption.GenerateAndSubmit:
+        case DependencyGraphOption.Clear: // Submit the empty dependency graph
             await submitDependencyGraphs(await uploadDependencyGraphs())
             return
     }

src/input-params.ts

@@ -82,6 +82,8 @@ export function getDependencyGraphOption(): DependencyGraphOption {
             return DependencyGraphOption.GenerateAndSubmit
         case 'download-and-submit':
             return DependencyGraphOption.DownloadAndSubmit
+        case 'clear':
+            return DependencyGraphOption.Clear
     }
     throw TypeError(
         `The value '${val} is not valid for 'dependency-graph. Valid values are: [disabled, generate-and-upload, generate-and-submit, download-and-submit]. The default value is 'disabled'.`
@@ -122,5 +124,6 @@ export enum DependencyGraphOption {
     Disabled,
     Generate,
     GenerateAndSubmit,
-    DownloadAndSubmit
+    DownloadAndSubmit,
+    Clear
 }