feat: add artifacts and metadata outputs (#327)

Co-authored-by: CrazyMax <crazy-max@users.noreply.github.com>

README.md

@@ -22,6 +22,7 @@ ___
   * [Install Only](#install-only)
 * [Customizing](#customizing)
   * [inputs](#inputs)
+  * [outputs](#outputs)
   * [environment variables](#environment-variables)
 * [Limitation](#limitation)
 * [Development](#development)
@@ -50,8 +51,6 @@ jobs:
       -
         name: Set up Go
         uses: actions/setup-go@v2
-        with:
-          go-version: 1.15
       -
         name: Run GoReleaser
         uses: goreleaser/goreleaser-action@v2
@@ -179,6 +178,15 @@ Following inputs can be used as `step.with` keys
 
 > **¹** Can be a fixed version like `v0.117.0` or a max satisfying semver one like `~> 0.132`. In this case this will return `v0.132.1`.
 
+### outputs
+
+Following outputs are available
+
+| Name              | Type    | Description                           |
+|-------------------|---------|---------------------------------------|
+| `artifacts`       | JSON    | Build result artifacts |
+| `metadata`        | JSON    | Build result metadata |
+
 ### environment variables
 
 Following environment variables can be used as `step.env` keys

__tests__/context.test.ts

@@ -0,0 +1,31 @@
+import * as os from 'os';
+import * as context from '../src/context';
+
+describe('setOutput', () => {
+  beforeEach(() => {
+    process.stdout.write = jest.fn();
+  });
+
+  it('setOutput produces the correct command', () => {
+    context.setOutput('some output', 'some value');
+    assertWriteCalls([`::set-output name=some output::some value${os.EOL}`]);
+  });
+
+  it('setOutput handles bools', () => {
+    context.setOutput('some output', false);
+    assertWriteCalls([`::set-output name=some output::false${os.EOL}`]);
+  });
+
+  it('setOutput handles numbers', () => {
+    context.setOutput('some output', 1.01);
+    assertWriteCalls([`::set-output name=some output::1.01${os.EOL}`]);
+  });
+});
+
+// Assert that process.stdout.write calls called only with the given arguments.
+function assertWriteCalls(calls: string[]): void {
+  expect(process.stdout.write).toHaveBeenCalledTimes(calls.length);
+  for (let i = 0; i < calls.length; i++) {
+    expect(process.stdout.write).toHaveBeenNthCalledWith(i + 1, calls[i]);
+  }
+}

action.yml

@@ -27,6 +27,12 @@ inputs:
     default: 'false'
     required: false
 
+outputs:
+  artifacts:
+    description: 'Build result artifacts'
+  metadata:
+    description: 'Build result metadata'
+
 runs:
   using: 'node12'
   main: 'dist/index.js'