Refactor artifact suffix computation into getArtifactSuffix

Author: mbg

lib/analyze-action-post.js

@@ -246,6 +246,33 @@ export async function tryUploadAllAvailableDebugArtifacts(
   }
 }
 
+/**
+ * When a build matrix is used, multiple different jobs arising from the matrix may attempt to upload
+ * workflow artifacts with the same base name. In that case, only one of the uploads will succeed and
+ * the others will fail. This function inspects the matrix object to compute a suffix for the artifact
+ * name that uniquely identifies the matrix values of the current job to avoid name clashes.
+ *
+ * @param matrix A stringified JSON value, usually the value of the `matrix` input.
+ * @returns A suffix that uniquely identifies the `matrix` value for the current job, or `""` if there
+ * is no matrix value.
+ */
+export function getArtifactSuffix(matrix: string | undefined): string {
+  let suffix = "";
+  if (matrix) {
+    try {
+      for (const [, matrixVal] of Object.entries(
+        JSON.parse(matrix) as any[][],
+      ).sort())
+        suffix += `-${matrixVal}`;
+    } catch {
+      core.info(
+        "Could not parse user-specified `matrix` input into JSON. The debug artifact will not be named with the user's `matrix` input.",
+      );
+    }
+  }
+  return suffix;
+}
+
 export async function uploadDebugArtifacts(
   logger: Logger,
   toUpload: string[],
@@ -279,21 +306,7 @@ export async function uploadDebugArtifacts(
     core.exportVariable("CODEQL_ACTION_ARTIFACT_SCAN_FINISHED", "true");
   }
 
-  let suffix = "";
-  const matrix = getOptionalInput("matrix");
-  if (matrix) {
-    try {
-      for (const [, matrixVal] of Object.entries(
-        JSON.parse(matrix) as any[][],
-      ).sort())
-        suffix += `-${matrixVal}`;
-    } catch {
-      core.info(
-        "Could not parse user-specified `matrix` input into JSON. The debug artifact will not be named with the user's `matrix` input.",
-      );
-    }
-  }
-
+  const suffix = getArtifactSuffix(getOptionalInput("matrix"));
   const artifactUploader = await getArtifactUploaderClient(logger, ghVariant);
 
   try {