Add optional base_url input to support GitHub Enterprise Octokit endpoints (#176)

Octokit currently defaults to `https://api.github.com`, which breaks API
calls against GitHub Enterprise Server unless `baseUrl` is set
explicitly.
This PR introduces an action-level configuration for API base URL and
threads it through the sub-actions that instantiate Octokit.

- **New action input**
  - Added optional `base_url` to root `action.yml`.
  - Intended format for GHE: `https://HOSTNAME/api/v3`.

- **Input propagation through composite action**
  - Forwarded `inputs.base_url` from the root action into:
    - `.github/actions/file`
    - `.github/actions/fix`

- **Octokit configuration updates**
- In `file/src/index.ts` and `fix/src/index.ts`, read `base_url` via
`core.getInput('base_url', {required: false})`.
  - Pass `baseUrl` into `new OctokitWithThrottling({...})`.
  - Keep existing behavior unchanged when `base_url` is omitted.

- **Docs update**
  - Added `base_url` to README action input table and workflow example.

- **Focused coverage**
- Added unit tests for both `file` and `fix` action entrypoints to
assert:
    - explicit `base_url` is passed as Octokit `baseUrl`
    - omitted `base_url` leaves Octokit on default API base URL behavior

```yaml
# workflow usage
- uses: github/accessibility-scanner@v2
  with:
    token: ${{ secrets.GH_TOKEN }}
    base_url: https://ghe.example.com/api/v3
```

```ts
const baseUrl = core.getInput('base_url', {required: false}) || undefined

const octokit = new OctokitWithThrottling({
  auth: token,
  baseUrl,
  throttle: { ... },
})
```

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Author: JoyceZhu

.github/actions/file/action.yml

@@ -11,6 +11,9 @@ inputs:
   token:
     description: "Token with fine-grained permission 'issues: write'"
     required: true
+  base_url:
+    description: "Optional base URL to pass into Octokit for the GitHub API (for example, `https://YOUR_HOSTNAME/api/v3` for GitHub Enterprise Server)"
+    required: false
   cached_filings_file:
     description: "Path to a JSON file containing cached filings from previous runs. Without this, duplicate issues may be filed."
     required: false

.github/actions/file/src/index.ts

@@ -22,6 +22,7 @@ export default async function () {
   const findings: Finding[] = JSON.parse(fs.readFileSync(findingsFile, 'utf8'))
   const repoWithOwner = core.getInput('repository', {required: true})
   const token = core.getInput('token', {required: true})
+  const baseUrl = core.getInput('base_url', {required: false})
   const screenshotRepo = core.getInput('screenshot_repository', {required: false}) || repoWithOwner
   const cachedFilingsFile = core.getInput('cached_filings_file', {required: false})
   const cachedFilings: (ResolvedFiling | RepeatedFiling)[] = cachedFilingsFile
@@ -30,12 +31,14 @@ export default async function () {
   const shouldOpenGroupedIssues = core.getBooleanInput('open_grouped_issues')
   core.debug(`Input: 'findings_file: ${findingsFile}'`)
   core.debug(`Input: 'repository: ${repoWithOwner}'`)
+  core.debug(`Input: 'base_url: ${baseUrl ?? '(default)'}'`)
   core.debug(`Input: 'screenshot_repository: ${screenshotRepo}'`)
   core.debug(`Input: 'cached_filings_file: ${cachedFilingsFile}'`)
   core.debug(`Input: 'open_grouped_issues: ${shouldOpenGroupedIssues}'`)
 
   const octokit = new OctokitWithThrottling({
     auth: token,
+    baseUrl,
     throttle: {
       onRateLimit: (retryAfter, options, octokit, retryCount) => {
         octokit.log.warn(`Request quota exhausted for request ${options.method} ${options.url}`)

.github/actions/fix/action.yml

@@ -11,6 +11,9 @@ inputs:
   token:
     description: "Personal access token (PAT) with fine-grained permissions 'issues: write' and 'pull_requests: write'"
     required: true
+  base_url:
+    description: "Optional base URL to pass into Octokit for the GitHub API (for example, `https://YOUR_HOSTNAME/api/v3` for GitHub Enterprise Server)"
+    required: false
 
 outputs:
   fixings_file:

.github/actions/fix/src/index.ts

@@ -17,11 +17,14 @@ export default async function () {
   const issues: IssueInput[] = JSON.parse(fs.readFileSync(issuesFile, 'utf8'))
   const repoWithOwner = core.getInput('repository', {required: true})
   const token = core.getInput('token', {required: true})
+  const baseUrl = core.getInput('base_url', {required: false}) || undefined
   core.debug(`Input: 'issues_file: ${issuesFile}'`)
   core.debug(`Input: 'repository: ${repoWithOwner}'`)
+  core.debug(`Input: 'base_url: ${baseUrl ?? '(default)'}'`)
 
   const octokit = new OctokitWithThrottling({
     auth: token,
+    baseUrl,
     throttle: {
       onRateLimit: (retryAfter, options, octokit, retryCount) => {
         octokit.log.warn(`Request quota exhausted for request ${options.method} ${options.url}`)

README.md

@@ -47,6 +47,7 @@ jobs:
           repository: REPLACE_THIS/REPLACE_THIS # Provide a repository name-with-owner (in the format "primer/primer-docs"). This is where issues will be filed and where Copilot will open PRs; more information below.
           token: ${{ secrets.GH_TOKEN }} # This token must have write access to the repo above (contents, issues, and PRs); more information below. Note: GitHub Actions' GITHUB_TOKEN cannot be used here.
           cache_key: REPLACE_THIS # Provide a filename that will be used when caching results. We recommend including the name or domain of the site being scanned.
+          # base_url: https://REPLACE_THIS # Optional: GitHub API base URL to pass into Octokit (required for GitHub Enterprise Server)
           # login_url: # Optional: URL of the login page if authentication is required
           # username: # Optional: Username for authentication
           # password: ${{ secrets.PASSWORD }} # Optional: Password for authentication (use secrets!)
@@ -118,6 +119,7 @@ Trigger the workflow manually or automatically based on your configuration. The
 | `repository`              | Yes      | Repository (with owner) for issues and PRs                                                                                                                                                          | `primer/primer-docs`                                        |
 | `token`                   | Yes      | PAT with write permissions (see above)                                                                                                                                                              | `${{ secrets.GH_TOKEN }}`                                   |
 | `cache_key`               | Yes      | Key for caching results across runs<br>Allowed: `A-Za-z0-9._/-`                                                                                                                                     | `cached_results-primer.style-main.json`                     |
+| `base_url`                | No       | GitHub API base URL used by Octokit. Set this for GitHub Enterprise Server (format: `https://HOSTNAME/api/v3`). Defaults to `https://api.github.com`                                              | `https://ghe.example.com/api/v3`                            |
 | `login_url`               | No       | If scanned pages require authentication, the URL of the login page                                                                                                                                  | `https://github.com/login`                                  |
 | `username`                | No       | If scanned pages require authentication, the username to use for login                                                                                                                              | `some-user`                                                 |
 | `password`                | No       | If scanned pages require authentication, the password to use for login                                                                                                                              | `${{ secrets.PASSWORD }}`                                   |

action.yml

@@ -12,6 +12,9 @@ inputs:
   token:
     description: "Personal access token (PAT) with fine-grained permissions 'contents: write', 'issues: write', and 'pull_requests: write'"
     required: true
+  base_url:
+    description: "Optional base URL for the GitHub API (for example, 'https://HOSTNAME/api/v3' for GitHub Enterprise Server)"
+    required: false
   cache_key:
     description: 'Key for caching results across runs'
     required: true
@@ -118,6 +121,7 @@ runs:
         findings_file: ${{ steps.find.outputs.findings_file }}
         repository: ${{ inputs.repository }}
         token: ${{ inputs.token }}
+        base_url: ${{ inputs.base_url }}
         cached_filings_file: ${{ steps.normalize_cache.outputs.cached_filings_file }}
         screenshot_repository: ${{ github.repository }}
         open_grouped_issues: ${{ inputs.open_grouped_issues }}
@@ -137,6 +141,7 @@ runs:
         issues_file: ${{ steps.get_issues_from_filings.outputs.issues_file }}
         repository: ${{ inputs.repository }}
         token: ${{ inputs.token }}
+        base_url: ${{ inputs.base_url }}
     - name: Set results output
       id: results
       shell: bash