Added option for local config file (#77)

* Added option for local config file

* Updated readme

* Moved error message to new file constants.js

* Updated README per suggestion

* Minor typo fix

Co-authored-by: Brian Duffey <bduff9@gmail.com>

.eslintrc.js

@@ -1,6 +1,6 @@
 module.exports = {
   parserOptions: {
-    ecmaVersion: 2018,
+    ecmaVersion: 2020,
   },
   env: {
     es6: true,

README.md

@@ -199,6 +199,12 @@ jobs:
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           config: .github/reviewers.yml # Config file location override
+          # Look for config locally during run instead of in repo.
+          # For instance, if you'd like to use a config file stored in external storage,
+          # you can fetch it before you run this action, then let this action pick it up with `use_local: true`.
+          # This defaults to false if not specified.
+          # See https://github.com/necojackarc/auto-request-review/issues/76 for more details.
+          use_local: true
 ```
 
 ### (Optional) GitHub Personal Access Token

action.yml

@@ -9,6 +9,9 @@ inputs:
   config:
     required: false
     default: '.github/auto_request_review.yml'
+  use_local:
+    required: false
+    default: 'false'
 runs:
   using: 'node16'
   main: 'dist/index.js'

src/constants.js

@@ -0,0 +1,5 @@
+const LOCAL_FILE_MISSING = 'Local file missing';
+
+module.exports = {
+  LOCAL_FILE_MISSING,
+};

src/github.js

@@ -1,9 +1,11 @@
 'use strict';
 
 const core = require('@actions/core');
+const fs = require('fs');
 const github = require('@actions/github');
 const partition = require('lodash/partition');
 const yaml = require('yaml');
+const { LOCAL_FILE_MISSING } = require('./constants');
 
 class PullRequest {
   // ref: https://developer.github.com/v3/pulls/#get-a-pull-request
@@ -36,15 +38,32 @@ async function fetch_config() {
   const context = get_context();
   const octokit = get_octokit();
   const config_path = get_config_path();
+  const useLocal = get_use_local();
+  let content = '';
 
-  const { data: response_body } = await octokit.repos.getContent({
-    owner: context.repo.owner,
-    repo: context.repo.repo,
-    path: config_path,
-    ref: context.ref,
-  });
+  if (!useLocal) {
+    const { data: response_body } = await octokit.repos.getContent({
+      owner: context.repo.owner,
+      repo: context.repo.repo,
+      path: config_path,
+      ref: context.ref,
+    });
+
+    content = Buffer.from(response_body.content, response_body.encoding).toString();
+  } else {
+    try {
+      content = fs.readFileSync(config_path).toString();
+
+      if (!content) {
+        throw new Error();
+      }
+    } catch (error) {
+      core.debug(`Error when reading local file: ${error}`);
+
+      throw new Error(LOCAL_FILE_MISSING);
+    }
+  }
 
-  const content = Buffer.from(response_body.content, response_body.encoding).toString();
   return yaml.parse(content);
 }
 
@@ -98,6 +117,7 @@ async function assign_reviewers(reviewers) {
 let context_cache;
 let token_cache;
 let config_path_cache;
+let use_local_cache;
 let octokit_cache;
 
 function get_context() {
@@ -112,6 +132,10 @@ function get_config_path() {
   return config_path_cache || (config_path_cache = core.getInput('config'));
 }
 
+function get_use_local() {
+  return use_local_cache ?? (use_local_cache = core.getInput('use_local') === 'true');
+}
+
 function get_octokit() {
   if (octokit_cache) {
     return octokit_cache;

src/index.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const core = require('@actions/core');
+const { LOCAL_FILE_MISSING } = require('./constants');
 const github = require('./github'); // Don't destructure this object to stub with sinon in tests
 
 const {
@@ -24,6 +25,12 @@ async function run() {
       core.warning('No configuration file is found in the base branch; terminating the process');
       return;
     }
+
+    if (error.message === LOCAL_FILE_MISSING) {
+      core.warning('No configuration file is found locally; terminating the process');
+      return;
+    }
+
     throw error;
   }