Move isDefaultSetup to actions-util.ts and change implementation

src/actions-util.ts

@@ -472,6 +472,11 @@ export function isSelfHostedRunner() {
   return process.env.RUNNER_ENVIRONMENT === "self-hosted";
 }
 
+/** Determines whether we are running in default setup. */
+export function isDefaultSetup(): boolean {
+  return getWorkflowEventName() === "dynamic";
+}
+
 export function prettyPrintInvocation(cmd: string, args: string[]): string {
   return [cmd, ...args].map((x) => (x.includes(" ") ? `'${x}'` : x)).join(" ");
 }

src/init-action.ts

@@ -13,6 +13,7 @@ import {
   getRequiredInput,
   getTemporaryDirectory,
   persistInputs,
+  isDefaultSetup,
 } from "./actions-util";
 import { getGitHubVersion } from "./api-client";
 import { CodeQL } from "./codeql";
@@ -723,13 +724,6 @@ async function recordZstdAvailability(
   );
 }
 
-/** Determines whether we are running in default setup. */
-function isDefaultSetup(): boolean {
-  // This is set to something in default setup runs.
-  // TODO: replace with something better, if there's something.
-  return process.env["CODE_SCANNING_WORKFLOW_FILE"] !== undefined;
-}
-
 /** Determines whether dependency caching is enabled. */
 function getDependencyCachingEnabled(): boolean {
   // If the workflow specified something always respect that