Assigns labels based on branch names

README.md

@@ -9,7 +9,7 @@
   </a>
 </p>
 
-Automatically label new pull requests based on the paths of files being changed.
+Automatically label new pull requests based on the paths of files being changed or the branch name.
 
 ## Usage
 
@@ -26,13 +26,15 @@ For more control over matching, you can provide a match object instead of a simp
 ```yml
 - any: ['list', 'of', 'globs']
   all: ['list', 'of', 'globs']
+  branch: ['list', 'of, 'globs']
 ```
 
-One or both fields can be provided for fine-grained matching. Unlike the top-level list, the list of path globs provided to `any` and `all` must ALL match against a path for the label to be applied.
+One or all fields can be provided for fine-grained matching. Unlike the top-level list, the list of path globs provided to `any` and `all` must ALL match against a path for the label to be applied.
 
 The fields are defined as follows:
 * `any`: match ALL globs against ANY changed path
 * `all`: match ALL globs against ALL changed paths
+* `branch`: match ANY glob against the branch name
 
 A simple path glob is the equivalent to `any: ['glob']`. More specifically, the following two configurations are equivalent:
 ```yml
@@ -61,6 +63,10 @@ label2: example2/*
 label3:
 - '**/*.txt'
 
+
+# Add 'label4' to any PR where the branch name starts with 'example4'
+label4:
+- branch: 'example4/**'
 ```
 
 #### Common Examples
@@ -87,6 +93,10 @@ source:
 frontend:
 - any: ['src/**/*.js']
   all: ['!src/main.js']
+
+ # Add 'feature' label to any branch that starts with `feature` or has a `feature` section in the name
+ feature:
+ - branch: ['feature/**', '*/feature/**']
 ```
 
 ### Create Workflow

__mocks__/@actions/github.ts

@@ -1,7 +1,13 @@
 export const context = {
   payload: {
     pull_request: {
-      number: 123
+      number: 123,
+      head: {
+        ref: 'head-branch-name'
+      },
+      base: {
+        ref: 'base-branch-name'
+      }
     }
   },
   repo: {

__tests__/branch.test.ts

@@ -0,0 +1,155 @@
+import {
+  getBranchName,
+  checkBranch,
+  toBranchMatchConfig,
+  BranchMatchConfig
+} from '../src/branch';
+import * as github from '@actions/github';
+
+jest.mock('@actions/core');
+jest.mock('@actions/github');
+
+describe('getBranchName', () => {
+  describe('when the pull requests base branch is requested', () => {
+    it('returns the base branch name', () => {
+      const result = getBranchName('base');
+      expect(result).toEqual('base-branch-name');
+    });
+  });
+
+  describe('when the pull requests head branch is requested', () => {
+    it('returns the head branch name', () => {
+      const result = getBranchName('head');
+      expect(result).toEqual('head-branch-name');
+    });
+  });
+
+  describe('when no branch is specified', () => {
+    it('returns the head branch name', () => {
+      const result = getBranchName();
+      expect(result).toEqual('head-branch-name');
+    });
+  });
+});
+
+describe('checkBranch', () => {
+  beforeEach(() => {
+    github.context.payload.pull_request!.head = {
+      ref: 'test/feature/123'
+    };
+    github.context.payload.pull_request!.base = {
+      ref: 'main'
+    };
+  });
+
+  describe('when a single pattern is provided', () => {
+    describe('and the pattern matches the head branch', () => {
+      it('returns true', () => {
+        const result = checkBranch(['^test']);
+        expect(result).toBe(true);
+      });
+    });
+
+    describe('and the pattern does not match the head branch', () => {
+      it('returns false', () => {
+        const result = checkBranch(['^feature/']);
+        expect(result).toBe(false);
+      });
+    });
+  });
+
+  describe('when multiple patterns are provided', () => {
+    describe('and at least one pattern matches', () => {
+      it('returns true', () => {
+        const result = checkBranch(['^test/', '^feature/']);
+        expect(result).toBe(true);
+      });
+    });
+
+    describe('and all patterns match', () => {
+      it('returns true', () => {
+        const result = checkBranch(['^test/', '/feature/']);
+        expect(result).toBe(true);
+      });
+    });
+
+    describe('and no patterns match', () => {
+      it('returns false', () => {
+        const result = checkBranch(['^feature/', '/test$']);
+        expect(result).toBe(false);
+      });
+    });
+  });
+
+  describe('when the branch to check is specified as the base branch', () => {
+    describe('and the pattern matches the base branch', () => {
+      it('returns true', () => {
+        const result = checkBranch(['^main$'], 'base');
+        expect(result).toBe(true);
+      });
+    });
+  });
+});
+
+describe('toBranchMatchConfig', () => {
+  describe('when there are no branch keys in the config', () => {
+    const config = {'changed-files': [{any: ['testing']}]};
+    it('returns an empty object', () => {
+      const result = toBranchMatchConfig(config);
+      expect(result).toMatchObject({});
+    });
+  });
+
+  describe('when the config contains a head-branch option', () => {
+    const config = {'head-branch': ['testing']};
+    it('sets headBranch in the matchConfig', () => {
+      const result = toBranchMatchConfig(config);
+      expect(result).toMatchObject<BranchMatchConfig>({
+        headBranch: ['testing']
+      });
+    });
+
+    describe('and the matching option is a string', () => {
+      const stringConfig = {'head-branch': 'testing'};
+
+      it('sets headBranch in the matchConfig', () => {
+        const result = toBranchMatchConfig(stringConfig);
+        expect(result).toMatchObject<BranchMatchConfig>({
+          headBranch: ['testing']
+        });
+      });
+    });
+  });
+
+  describe('when the config contains a base-branch option', () => {
+    const config = {'base-branch': ['testing']};
+    it('sets headBranch in the matchConfig', () => {
+      const result = toBranchMatchConfig(config);
+      expect(result).toMatchObject<BranchMatchConfig>({
+        baseBranch: ['testing']
+      });
+    });
+
+    describe('and the matching option is a string', () => {
+      const stringConfig = {'base-branch': 'testing'};
+
+      it('sets headBranch in the matchConfig', () => {
+        const result = toBranchMatchConfig(stringConfig);
+        expect(result).toMatchObject<BranchMatchConfig>({
+          baseBranch: ['testing']
+        });
+      });
+    });
+  });
+
+  describe('when the config contains both a base-branch and head-branch option', () => {
+    const config = {'base-branch': ['testing'], 'head-branch': ['testing']};
+    it('sets headBranch in the matchConfig', () => {
+      const result = toBranchMatchConfig(config);
+      expect(result).toMatchObject<BranchMatchConfig>({
+        baseBranch: ['testing'],
+        headBranch: ['testing']
+      });
+    });
+  });
+});

__tests__/fixtures/branches.yml

@@ -0,0 +1,11 @@
+test-branch:
+  - head-branch: "^test/"
+
+feature-branch:
+  - head-branch: "/feature/"
+
+bug-branch:
+  - head-branch: "^bug/|fix/"
+
+array-branch:
+  - head-branch: ["^array/"]

__tests__/fixtures/only_pdfs.yml

@@ -1,2 +1,3 @@
 touched-a-pdf-file:
-  - any: ['*.pdf']
+  - changed-files:
+    - any: ['*.pdf']

__tests__/labeler.test.ts

@@ -1,4 +1,4 @@
-import {checkGlobs} from '../src/labeler';
+import {checkGlobs, MatchConfig} from '../src/labeler';
 
 import * as core from '@actions/core';
 
@@ -10,7 +10,11 @@ beforeAll(() => {
   });
 });
 
-const matchConfig = [{any: ['*.txt']}];
+// I have to double cast here as this is what the output from js-yaml looks like which then gets
+// transformed in toMatchConfig
+const matchConfig = [
+  {'changed-files': [{any: ['*.txt']}]}
+] as unknown as MatchConfig[];
 
 describe('checkGlobs', () => {
   it('returns true when our pattern does match changed files', () => {

__tests__/main.test.ts

@@ -15,6 +15,7 @@ const paginateMock = jest.spyOn(gh, 'paginate');
 const getPullMock = jest.spyOn(gh.rest.pulls, 'get');
 
 const yamlFixtures = {
+  'branches.yml': fs.readFileSync('__tests__/fixtures/branches.yml'),
   'only_pdfs.yml': fs.readFileSync('__tests__/fixtures/only_pdfs.yml')
 };
 
@@ -102,6 +103,64 @@ describe('run', () => {
     expect(addLabelsMock).toHaveBeenCalledTimes(0);
     expect(removeLabelMock).toHaveBeenCalledTimes(0);
   });
+
+  it('adds labels based on the branch names that match the regexp pattern', async () => {
+    github.context.payload.pull_request!.head = {ref: 'test/testing-time'};
+    usingLabelerConfigYaml('branches.yml');
+    await run();
+
+    expect(addLabelsMock).toHaveBeenCalledTimes(1);
+    expect(addLabelsMock).toHaveBeenCalledWith({
+      owner: 'monalisa',
+      repo: 'helloworld',
+      issue_number: 123,
+      labels: ['test-branch']
+    });
+  });
+
+  it('adds multiple labels based on branch names that match different regexp patterns', async () => {
+    github.context.payload.pull_request!.head = {
+      ref: 'test/feature/123'
+    };
+    usingLabelerConfigYaml('branches.yml');
+    await run();
+
+    expect(addLabelsMock).toHaveBeenCalledTimes(1);
+    expect(addLabelsMock).toHaveBeenCalledWith({
+      owner: 'monalisa',
+      repo: 'helloworld',
+      issue_number: 123,
+      labels: ['test-branch', 'feature-branch']
+    });
+  });
+
+  it('it can support multiple branches by batching', async () => {
+    github.context.payload.pull_request!.head = {ref: 'fix/123'};
+    usingLabelerConfigYaml('branches.yml');
+    await run();
+
+    expect(addLabelsMock).toHaveBeenCalledTimes(1);
+    expect(addLabelsMock).toHaveBeenCalledWith({
+      owner: 'monalisa',
+      repo: 'helloworld',
+      issue_number: 123,
+      labels: ['bug-branch']
+    });
+  });
+
+  it('it can support multiple branches by providing an array', async () => {
+    github.context.payload.pull_request!.head = {ref: 'array/123'};
+    usingLabelerConfigYaml('branches.yml');
+    await run();
+
+    expect(addLabelsMock).toHaveBeenCalledTimes(1);
+    expect(addLabelsMock).toHaveBeenCalledWith({
+      owner: 'monalisa',
+      repo: 'helloworld',
+      issue_number: 123,
+      labels: ['array-branch']
+    });
+  });
 });
 
 function usingLabelerConfigYaml(fixtureName: keyof typeof yamlFixtures): void {