Change detection via git + rename `githubToken` to `token` (#9)

.github/filters.yml

@@ -1,2 +1,4 @@
+error:
+  - not_existing_path/**/*
 any:
   - "**/*"

.github/workflows/pull-request-verification.yml

@@ -16,7 +16,23 @@ jobs:
         npm install
         npm run all
 
-  test:
+  test-inline:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: ./
+      id: filter
+      with:
+        filters: |
+          error:
+            - not_existing_path/**/*
+          any:
+            - "**/*"
+    - name: filter-test
+      if: steps.filter.outputs.any != 'true' || steps.filter.outputs.error == 'true'
+      run: exit 1
+
+  test-external:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
@@ -24,16 +40,19 @@ jobs:
       id: filter
       with:
         filters: '.github/filters.yml'
-    - uses: ./
-      id: inlineFilter
-      with:
-        filters: |
-          src:
-            - src/**/*
-          tests:
-            - __tests__/**/*
-          any:
-            - "**/*"
     - name: filter-test
-      if: steps.filter.outputs.any != 'true' || steps.inlineFilter.outputs.any != 'true'
+      if: steps.filter.outputs.any != 'true' || steps.filter.outputs.error == 'true'
+      run: exit 1
+
+  test-without-token:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: ./
+      id: filter
+      with:
+        token: ''
+        filters: '.github/filters.yml'
+    - name: filter-test
+      if: steps.filter.outputs.any != 'true' || steps.filter.outputs.error == 'true'
       run: exit 1

README.md

@@ -21,7 +21,7 @@ Corresponding output variable will be created to indicate if there's a changed f
 Output variables can be later used in the `if` clause to conditionally run specific steps.
 
 ### Inputs
-- **`githubToken`**: GitHub Access Token - defaults to `${{ github.token }}`
+- **`token`**: GitHub Access Token - defaults to `${{ github.token }}`
 - **`filters`**: Path to the configuration file or directly embedded string in YAML format. Filter configuration is a dictionary, where keys specifies rule names and values are lists of file path patterns.
 
 ### Outputs
@@ -78,10 +78,11 @@ jobs:
 
 ## How it works
 
-1. Required inputs are checked (`githubToken` & `filters`)
-2. Provided access token is used to fetch list of changed files.
-3. For each filter rule it checks if there is any matching file
-4. Output variables are set
+1. Required inputs are checked (`filters`)
+2. If token was provided, it's used to fetch list of changed files from Github API.
+3. If token was not provided, base branch is fetched and changed files are detected using `git diff-index` command.
+4. For each filter rule it checks if there is any matching file
+5. Output variables are set
 
 ## Difference from related projects:
 

action.yml

@@ -2,9 +2,9 @@ name: 'Pull request changed files filter'
 description: 'Enables conditional execution of workflow job steps considering which files are modified by a pull request.'
 author: 'Michal Dorner <dorner.michal@gmail.com>'
 inputs:
-  githubToken:
+  token:
     description: 'GitHub Access Token'
-    required: true
+    required: false
     default: ${{ github.token }}
   filters:
     description: 'Path to the configuration file or YAML string with filters definition'

package-lock.json

@@ -9,6 +9,14 @@
       "resolved": "https://registry.npmjs.org/@actions/core/-/core-1.2.4.tgz",
       "integrity": "sha512-YJCEq8BE3CdN8+7HPZ/4DxJjk/OkZV2FFIf+DlZTC/4iBlzYCD5yjRR6eiOS5llO11zbRltIRuKAjMKaWTE6cg=="
     },
+    "@actions/exec": {
+      "version": "1.0.4",
+      "resolved": "https://registry.npmjs.org/@actions/exec/-/exec-1.0.4.tgz",
+      "integrity": "sha512-4DPChWow9yc9W3WqEbUj8Nr86xkpyE29ZzWjXucHItclLbEW6jr80Zx4nqv18QL6KK65+cifiQZXvnqgTV6oHw==",
+      "requires": {
+        "@actions/io": "^1.0.1"
+      }
+    },
     "@actions/github": {
       "version": "2.2.0",
       "resolved": "https://registry.npmjs.org/@actions/github/-/github-2.2.0.tgz",
@@ -27,6 +35,11 @@
         "tunnel": "0.0.6"
       }
     },
+    "@actions/io": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/@actions/io/-/io-1.0.2.tgz",
+      "integrity": "sha512-J8KuFqVPr3p6U8W93DOXlXW6zFvrQAJANdS+vw0YhusLIq+bszW8zmK2Fh1C2kDPX8FMvwIl1OUcFgvJoXLbAg=="
+    },
     "@babel/code-frame": {
       "version": "7.5.5",
       "resolved": "https://registry.npmjs.org/@babel/code-frame/-/code-frame-7.5.5.tgz",

package.json

@@ -26,6 +26,7 @@
   "license": "MIT",
   "dependencies": {
     "@actions/core": "^1.2.4",
+    "@actions/exec": "^1.0.4",
     "@actions/github": "^2.2.0",
     "@octokit/webhooks": "^7.6.2",
     "minimatch": "^3.0.4"

src/git.ts

@@ -0,0 +1,26 @@
+import {exec} from '@actions/exec'
+
+export async function fetchBranch(base: string): Promise<void> {
+  const exitCode = await exec('git', ['fetch', '--depth=1', 'origin', base])
+  if (exitCode !== 0) {
+    throw new Error(`Fetching branch ${base} failed, exiting`)
+  }
+}
+
+export async function getChangedFiles(base: string): Promise<string[]> {
+  let output = ''
+  const exitCode = await exec('git', ['diff-index', '--name-only', base], {
+    listeners: {
+      stdout: (data: Buffer) => (output += data.toString())
+    }
+  })
+
+  if (exitCode !== 0) {
+    throw new Error(`Couldn't determine changed files, exiting`)
+  }
+
+  return output
+    .split('\n')
+    .map(s => s.trim())
+    .filter(s => s.length > 0)
+}

src/main.ts

@@ -4,16 +4,14 @@ import * as github from '@actions/github'
 import {Webhooks} from '@octokit/webhooks'
 
 import Filter from './filter'
+import * as git from './git'
 
 async function run(): Promise<void> {
   try {
-    const token = core.getInput('githubToken', {required: true})
+    const token = core.getInput('token', {required: false})
     const filtersInput = core.getInput('filters', {required: true})
-
     const filtersYaml = isPathInput(filtersInput) ? getConfigFileContent(filtersInput) : filtersInput
 
-    const client = new github.GitHub(token)
-
     if (github.context.eventName !== 'pull_request') {
       core.setFailed('This action can be triggered only by pull_request event')
       return
@@ -21,7 +19,8 @@ async function run(): Promise<void> {
 
     const pr = github.context.payload.pull_request as Webhooks.WebhookPayloadPullRequestPullRequest
     const filter = new Filter(filtersYaml)
-    const files = await getChangedFiles(client, pr)
+    const files = token ? await getChangedFilesFromApi(token, pr) : await getChangedFilesFromGit(pr)
+
     const result = filter.match(files)
     for (const key in result) {
       core.setOutput(key, String(result[key]))
@@ -47,11 +46,21 @@ function getConfigFileContent(configPath: string): string {
   return fs.readFileSync(configPath, {encoding: 'utf8'})
 }
 
+// Fetch base branch and use `git diff` to determine changed files
+async function getChangedFilesFromGit(pullRequest: Webhooks.WebhookPayloadPullRequestPullRequest): Promise<string[]> {
+  core.debug('Fetching base branch and using `git diff-index` to determine changed files')
+  const baseRef = pullRequest.base.ref
+  await git.fetchBranch(baseRef)
+  return await git.getChangedFiles(pullRequest.base.sha)
+}
+
 // Uses github REST api to get list of files changed in PR
-async function getChangedFiles(
-  client: github.GitHub,
+async function getChangedFilesFromApi(
+  token: string,
   pullRequest: Webhooks.WebhookPayloadPullRequestPullRequest
 ): Promise<string[]> {
+  core.debug('Fetching list of modified files from Github API')
+  const client = new github.GitHub(token)
   const pageSize = 100
   const files: string[] = []
   for (let page = 0; page * pageSize < pullRequest.changed_files; page++) {