feat(generate-matrix): add generate-matrix helper (#351)

* feat(generate-matrix): add generate-matrix helper

* make batches optional

.github/workflows/generate-matrix.yml

@@ -0,0 +1,43 @@
+name: Generate Matrix
+
+on:
+  pull_request:
+    branches: [ main ]
+    paths:
+      - 'src/helpers/generate-matrix.ts'
+
+jobs:
+  scheduler:
+    name: Determine packages to build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - uses: ./
+        id: matrix
+        with:
+          helper: generate-matrix
+          paths: |
+            test/path/1
+            test/path/2
+            test/path/3
+
+    outputs:
+      matrix: ${{ steps.matrix.outputs.output }}
+
+  build:
+    runs-on: ubuntu-latest
+    needs: scheduler
+    strategy:
+      matrix: ${{ fromJson(needs.scheduler.outputs.matrix) }}
+    steps:
+      - run: echo "Run each job using ${{ matrix.path }}"
+
+  build-status:
+    runs-on: ubuntu-latest
+    if: always()
+    needs: build
+    steps:
+      - name: Check build status
+        run: exit ${{ (needs.build.result == 'failure' || needs.build.result == 'cancelled') && 1 || 0 }}

README.md

@@ -127,6 +127,9 @@ The following parameters can be used for additional control over when it is safe
 ### [filter-paths](.github/workflows/filter-paths.yml)
   * Returns `true` if specified file paths have changed for a PR, and `false` otherwise
 
+### [generate-matrix](.github/workflows/generate-matrix.yml)
+  * Returns a job matrix JSON for dynamically running workflows
+
 ### [generate-path-matrix](.github/workflows/generate-path-matrix.yml)
   * Returns a job matrix JSON for dynamically running workflows only for changed file paths
   * Can be used to parallelize similar jobs, which can be useful in a monorepo environment. More information on matrix strategies can be found [here](https://docs.github.com/en/actions/learn-github-actions/workflow-syntax-for-github-actions#jobsjob_idstrategymatrix)

dist/index.js

@@ -20083,6 +20083,14 @@ var map = {
 		228,
 		794
 	],
+	"./generate-matrix": [
+		1839,
+		839
+	],
+	"./generate-matrix.ts": [
+		1839,
+		839
+	],
 	"./generate-path-matrix": [
 		2533,
 		832,

src/helpers/generate-matrix.ts

@@ -0,0 +1,27 @@
+/*
+Copyright 2021 Expedia, Inc.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    https://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { HelperInputs } from '../types/generated';
+import { chunk } from 'lodash';
+
+export class GenerateMatrix extends HelperInputs {
+  paths = '';
+  batches?: string;
+}
+
+export const generateMatrix = ({ paths, batches = '1' }: GenerateMatrix) => {
+  const matrixValues = paths.split(/[\n,]/);
+  return {
+    include: chunk(matrixValues, Math.ceil(matrixValues.length / Number(batches))).map(chunk => ({ path: chunk.join(',') }))
+  };
+};

test/helpers/generate-matrix.test.ts

@@ -0,0 +1,39 @@
+/*
+Copyright 2021 Expedia, Inc.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    https://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { generateMatrix } from '../../src/helpers/generate-matrix';
+
+jest.mock('@actions/core');
+jest.mock('@actions/github', () => ({
+  context: { repo: { repo: 'repo', owner: 'owner' }, issue: { number: 123 } },
+  getOctokit: jest.fn()
+}));
+
+describe('generateMatrix', () => {
+  it('should generate matrix json with appropriate batching', () => {
+    const result = generateMatrix({ paths: 'path/1,path/2,path/3,path/4,path/5', batches: '3' });
+    expect(result).toEqual({
+      include: [
+        {
+          path: 'path/1,path/2'
+        },
+        {
+          path: 'path/3,path/4'
+        },
+        {
+          path: 'path/5'
+        }
+      ]
+    });
+  });
+});