feat(sc-30416): add support for user mapping file to resolve Slack user by GitHub login

- Introduce `user_mapping_filepath` input in `action.yml` to optionally
  provide a mapping file for Slack user details by GitHub login.

- Update `getMessageAuthorFactory` and related logic to use the mapping
  file if provided, avoiding Slack and GitHub API calls when possible.

- Add fallback and error handling for mapping file usage.

- Refactor main entry to pass `user_mapping_filepath` to author
  resolution.

Signed-off-by: Jake Schurch <[email protected]>

Author: jakeschurch

src/getMessageAuthorFactory.ts

@@ -13,24 +13,26 @@ export type GetMessageAuthor = (
   options?: GetMessageAuthorOptions
 ) => Promise<MessageAuthor | null>
 
-interface GetMessageAuthorOptions {
+interface GetMessageAuthorOptions extends GetMessageAuthorFactoryOptions {
   /** `false` falls back to GitHub username, skipping a conservatively rate-limited Slack API call */
-  withSlackUserId: boolean
-  userMappingFilepath: string
+  withSlackUserId?: boolean
+}
+
+interface GetMessageAuthorFactoryOptions {
+  userMappingFilepath?: string
 }
 
 export function getMessageAuthorFactory(
   octokit: OctokitClient,
   slack: SlackClient,
-  options: GetMessageAuthorOptions = {
-    withSlackUserId: false,
-    userMappingFilepath: ''
+  options: GetMessageAuthorFactoryOptions = {
+    userMappingFilepath: undefined
   }
 ): GetMessageAuthor {
   return async (
-    messageAuthorOptions: GetMessageAuthorOptions = options
+    {withSlackUserId}: GetMessageAuthorOptions = {withSlackUserId: false}
   ): Promise<MessageAuthor | null> => {
-    return getMessageAuthor(octokit, slack, messageAuthorOptions)
+    return getMessageAuthor(octokit, slack, {withSlackUserId, ...options})
   }
 }
 

src/main.ts

@@ -58,7 +58,9 @@ async function notifySlack(
   octokit: OctokitClient,
   slack: SlackClient
 ): Promise<void> {
-  const getMessageAuthor = getMessageAuthorFactory(octokit, slack, {userMappingFilepath: getInput(user_mapping_filepath)})
+  const getMessageAuthor = getMessageAuthorFactory(octokit, slack, {
+    userMappingFilepath: getInput('user_mapping_filepath')
+  })
   const ts = await postMessage({octokit, slack, getMessageAuthor})
 
   if (ts) {