improve edit summary usage

README.md

@@ -25,7 +25,8 @@ jobs:
       # Run build and ensure tests are passing before deployment
       - run: npm run --if-present build
       - run: npm run --if-present test
-      - uses: wikimedia-gadgets/deploy-action@v1
+      - name: Deploy to Wikipedia 
+        uses: wikimedia-gadgets/deploy-action@v1
         with:
           paths: 'src/myscript.js User:SD0001/myscript.js'
           apiUrl: 'https://en.wikipedia.org/w/api.php'
@@ -34,6 +35,12 @@ jobs:
           ### OR ###
           username: ${{ secrets.USERNAME }}
           password: ${{ secrets.PASSWORD }}
+
+          # Optional, defaults to "Updating from repo at $BRANCH ($SHA)"
+          # If provided, $BRANCH will be expanded to branch name, $SHA to 8-character SHA1, 
+          # and $SOURCE to the source file path.
+          # You can also use values from the context (https://docs.github.com/en/actions/learn-github-actions/contexts#github-context) such as ${{github.repository}}
+          editSummary: ''
 ```
 This action as written above will be triggered every time a commit is pushed to master branch. For alternative trigger mechanisms (such as triggering when a release is published), refer to [GitHub docs](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#on).
 

action.yml

@@ -3,8 +3,8 @@ description: 'Deploy user scripts or gadgets to Wikimedia sites'
 author: 'Siddharth VP'
 inputs:
   apiUrl:
-    required: true
     description: 'API URL of the wiki, eg. https://en.wikipedia.org/w/api.php'
+    required: true
   username:
     description: 'Username for use with BotPassword authentication'
   password:
@@ -13,8 +13,10 @@ inputs:
     description: 'Access token for use with OAuth2 authentication'
   paths:
     description: 'Paths to sync with wiki pages. Can be multiple lines. Each line should be path-to-file-in-repo <space> wiki-page-title. Note the local file path must not contain spaces.'
+    required: true
   editSummary:
     description: 'Edit summary to use while updating pages'
+    default: 'Updating from repo at $BRANCH ($SHA)'
 runs:
   using: 'node16'
   main: 'dist/index.js'

src/index.ts

@@ -24,14 +24,15 @@ export async function run(): Promise<void> {
       )
     }
 
-    const context = github.context
-    const paths = await processPaths(core.getMultilineInput('paths'))
-    const editSummary =
-      core.getInput('editSummary') || `Updating from repo at ${context.ref}`
+    const paths = await processPaths(
+      core.getMultilineInput('paths', {required: true})
+    )
 
+    const editSummaryRaw =
+      core.getInput('editSummary') || 'Updating from repo at $BRANCH ($SHA)'
     const baseRequestParams = {apiUrl, username, password, oauth2Token}
 
-    await requestEdits(baseRequestParams, paths, editSummary)
+    await requestEdits(baseRequestParams, paths, editSummaryRaw)
   } catch (error) {
     if (error instanceof Error) core.setFailed(error.message)
   }
@@ -68,11 +69,15 @@ export async function processPath(
 export function requestEdits(
   baseParams: Record<string, string>,
   paths: Array<[string, string]>,
-  editSummary: string
+  editSummaryRaw: string
 ) {
   return Promise.all(
     paths.map(async path => {
       let [sourceFile, wikiPage] = path
+      const editSummary = editSummaryRaw
+        .replace(/\$BRANCH/, github.context.ref.replace(/^refs\/heads\//, ''))
+        .replace(/\$SHA/, github.context.sha.slice(0, 8))
+        .replace(/\$SOURCE/, sourceFile)
       let requestParams = {
         ...baseParams,
         page: wikiPage,