Do not fail if the workflow has been deleted

src/actions-util.test.ts

@@ -186,17 +186,6 @@ test("validateWorkflow() when on.push is mismatched for pull_request", (t) => {
   t.deepEqual(errors, [actionsutil.ErrMismatchedBranches]);
 });
 
-test("validateWorkflow() when on.pull_request for every branch but push specifies branches", (t) => {
-  const errors = actionsutil.validateWorkflow({
-    on: {
-      push: { branches: ["main"] },
-      pull_request: null,
-    },
-  });
-
-  t.deepEqual(errors, [actionsutil.ErrMismatchedBranches]);
-});
-
 test("validateWorkflow() when HEAD^2 is checked out", (t) => {
   const errors = actionsutil.validateWorkflow({
     on: ["push", "pull_request"],

src/actions-util.ts

@@ -190,19 +190,13 @@ export function validateWorkflow(doc: Workflow): string[] {
       }
     }
 
-    if (doc.on.push) {
+    if (doc.on.push && doc.on.pull_request) {
       const push = doc.on.push.branches || [];
-      if (doc.on.pull_request) {
-        const pull_request = doc.on.pull_request.branches || [];
+      const pull_request = doc.on.pull_request.branches || [];
 
-        const intersects = pull_request.filter(
-          (value) => !push.includes(value)
-        );
+      const intersects = pull_request.filter((value) => !push.includes(value));
 
-        if (intersects.length > 0) {
-          errors.push(ErrMismatchedBranches);
-        }
-      } else if (push.length > 0) {
+      if (intersects.length > 0) {
         errors.push(ErrMismatchedBranches);
       }
     }
@@ -223,14 +217,37 @@ export function validateWorkflow(doc: Workflow): string[] {
   return errors;
 }
 
-export async function getWorkflow(): Promise<Workflow> {
+export async function getWorkflowError(): Promise<string | undefined> {
+  const workflow = await getWorkflow();
+
+  if (workflow === undefined) {
+    return undefined;
+  }
+
+  const workflowErrors = validateWorkflow(workflow);
+
+  if (workflowErrors.length === 0) {
+    return undefined;
+  }
+
+  return `${workflowErrors.length} issue${
+    workflowErrors.length === 1 ? " was" : "s were"
+  } detected with this workflow: ${workflowErrors.join(", ")}`;
+}
+
+export async function getWorkflow(): Promise<Workflow | undefined> {
   const relativePath = await getWorkflowPath();
   const absolutePath = path.join(
     getRequiredEnvParam("GITHUB_WORKSPACE"),
     relativePath
   );
 
-  return yaml.safeLoad(fs.readFileSync(absolutePath, "utf-8"));
+  try {
+    return yaml.safeLoad(fs.readFileSync(absolutePath, "utf-8"));
+  } catch (e) {
+    core.warning(`Could not read workflow: ${e.toString()}`);
+    return undefined;
+  }
 }
 
 /**

src/init-action.ts

@@ -96,19 +96,10 @@ async function run() {
   try {
     actionsUtil.prepareLocalRunEnvironment();
 
-    const workflowErrors = actionsUtil.validateWorkflow(
-      await actionsUtil.getWorkflow()
-    );
+    const workflowError = await actionsUtil.getWorkflowError();
 
-    const workflowErrorMessage =
-      workflowErrors.length > 0
-        ? `${workflowErrors.length} issue${
-            workflowErrors.length === 1 ? " was" : "s were"
-          } detected with this workflow: ${workflowErrors.join(", ")}`
-        : undefined;
-
-    if (workflowErrorMessage !== undefined) {
-      core.warning(workflowErrorMessage);
+    if (workflowError !== undefined) {
+      core.warning(workflowError);
     }
 
     if (
@@ -117,7 +108,7 @@ async function run() {
           "init",
           "starting",
           startedAt,
-          workflowErrorMessage
+          workflowError
         )
       ))
     ) {