feat: add additional input to define how to fail the action

README.md

@@ -12,6 +12,7 @@ Let's suppose you have a workflow with a job in it that at the end uploads an ar
 
 ```yaml
 - name: Download artifact
+  id: download-artifact
   uses: dawidd6/action-download-artifact@v2
   with:
     # Optional, GitHub token, a Personal Access Token with `public_repo` scope if needed
@@ -59,4 +60,21 @@ Let's suppose you have a workflow with a job in it that at the end uploads an ar
     # Optional, choose to skip unpacking the downloaded artifact(s)
     # default false
     skip_unpack: false
+    # Optional, choose how to exit the action if no artifact is found
+    # can be one of:
+    #  "fail", "warn", "ignore"
+    # default ignore
+    if_no_artifact_found: fail
 ```
+
+## Output
+
+The `found_artifact` step output contains a boolean value indicating whether an artifact was found.
+```yaml
+steps:
+  - id: download-artifact
+    uses: dawidd6/action-download-artifact@v2
+
+  - name: 'use artifact'
+    if: steps.download-artifact.found_artifact
+    run: echo "Found artifact"

action.yml

@@ -63,11 +63,17 @@ inputs:
   dry_run:
     description: Check the existence of artifact(s) without downloading.
     required: false
+  if_no_artifact_found:
+    required: false
+    description: choose how to exit the action if no artifact is found
+    default: "fail"
 outputs:
   error_message:
     description: The error message, if an error occurs
   dry_run:
     description: Boolean output which is true if the dry run was successful and false otherwise.
+  found_artifact:
+    description: Boolean output which is true if the artifact was found and false otherwise.
 runs:
   using: node16
   main: main.js

main.js

@@ -16,6 +16,7 @@ async function main() {
         const path = core.getInput("path", { required: true })
         const name = core.getInput("name")
         const skipUnpack = core.getInput("skip_unpack")
+        const ifNoArtifactFound = core.getInput("if_no_artifact_found")
         let workflow = core.getInput("workflow")
         let workflowConclusion = core.getInput("workflow_conclusion")
         let pr = core.getInput("pr")
@@ -39,7 +40,7 @@ async function main() {
                 owner: owner,
                 repo: repo,
                 run_id: runID || github.context.runId,
-            });
+            })
             workflow = run.data.workflow_id
         }
 
@@ -140,7 +141,8 @@ async function main() {
         }
 
         if (!runID) {
-            throw new Error("no matching workflow run found with any artifacts?")
+            setExitMessage(ifNoArtifactFound, "no matching workflow run found with any artifacts?")
+            return
         }
 
         let artifacts = await client.paginate(client.rest.actions.listWorkflowRunArtifacts, {
@@ -167,11 +169,13 @@ async function main() {
         if (dryRun) {
             if (artifacts.length == 0) {
                 core.setOutput("dry_run", false)
+                core.setOutput("found_artifact", false)
                 return
             } else {
                 core.setOutput("dry_run", true)
+                core.setOutput("found_artifact", true)
                 core.info('==> (found) Artifacts')
-                for (const artifact of artifacts){
+                for (const artifact of artifacts) {
                     const size = filesize(artifact.size_in_bytes, { base: 10 })
                     core.info(`\t==> Artifact:`)
                     core.info(`\t==> ID: ${artifact.id}`)
@@ -183,10 +187,13 @@ async function main() {
         }
 
         if (artifacts.length == 0) {
-            throw new Error("no artifacts found")
+            setExitMessage(ifNoArtifactFound, "no artifacts found")
+            return
         }
 
+        core.setOutput("found_artifact", true)
         for (const artifact of artifacts) {
+
             core.info(`==> Artifact: ${artifact.id}`)
 
             const size = filesize(artifact.size_in_bytes, { base: 10 })
@@ -224,9 +231,26 @@ async function main() {
             core.endGroup()
         }
     } catch (error) {
+        core.setOutput("found_artifact", false)
         core.setOutput("error_message", error.message)
         core.setFailed(error.message)
     }
+
+    function setExitMessage(ifNoArtifactFound, message) {
+        core.setOutput("found_artifact", false)
+        switch (ifNoArtifactFound) {
+            case "fail":
+                core.setFailed(message)
+                break
+            case "warn":
+                core.warning(message)
+                break
+            case "ignore":
+            default:
+                core.info(message)
+                break
+        }
+    }
 }
 
 main()