Fix setOutput

__tests__/context.test.ts

@@ -1,4 +1,5 @@
 import * as fs from 'fs';
+import * as os from 'os';
 import * as path from 'path';
 
 import * as context from '../src/context';
@@ -171,6 +172,27 @@ describe('asyncForEach', () => {
   });
 });
 
+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${os.EOL}`]);
+  });
+});
+
 // See: https://github.com/actions/toolkit/blob/master/packages/core/src/core.ts#L67
 function getInputName(name: string): string {
   return `INPUT_${name.replace(/ /g, '_').toUpperCase()}`;
@@ -179,3 +201,11 @@ function getInputName(name: string): string {
 function setInput(name: string, value: string): void {
   process.env[getInputName(name)] = value;
 }
+
+// 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]);
+  }
+}

src/context.ts

@@ -1,5 +1,6 @@
 import csvparse from 'csv-parse/lib/sync';
 import * as core from '@actions/core';
+import {issueCommand} from '@actions/core/lib/command';
 import * as fs from 'fs';
 import * as os from 'os';
 import * as path from 'path';
@@ -66,3 +67,8 @@ export const asyncForEach = async (array, callback) => {
     await callback(array[index], index, array);
   }
 };
+
+// FIXME: Temp fix https://github.com/actions/toolkit/issues/777
+export function setOutput(name: string, value: any): void {
+  issueCommand('set-output', {name}, value);
+}

src/main.ts

@@ -1,5 +1,5 @@
 import * as fs from 'fs';
-import {getInputs, Inputs} from './context';
+import {getInputs, Inputs, setOutput} from './context';
 import * as github from './github';
 import {Meta, Version} from './meta';
 import * as core from '@actions/core';
@@ -36,7 +36,7 @@ async function run() {
       core.info(version.main || '');
       core.endGroup();
     }
-    core.setOutput('version', version.main || '');
+    setOutput('version', version.main || '');
 
     // Docker tags
     const tags: Array<string> = meta.getTags();
@@ -49,7 +49,7 @@ async function run() {
       }
       core.endGroup();
     }
-    core.setOutput('tags', tags.join(inputs.sepTags));
+    setOutput('tags', tags.join(inputs.sepTags));
 
     // Docker labels
     const labels: Array<string> = meta.getLabels();
@@ -58,14 +58,14 @@ async function run() {
       core.info(label);
     }
     core.endGroup();
-    core.setOutput('labels', labels.join(inputs.sepLabels));
+    setOutput('labels', labels.join(inputs.sepLabels));
 
     // Bake definition file
     const bakeFile: string = meta.getBakeFile();
     core.startGroup(`Bake definition file`);
     core.info(fs.readFileSync(bakeFile, 'utf8'));
     core.endGroup();
-    core.setOutput('bake-file', bakeFile);
+    setOutput('bake-file', bakeFile);
   } catch (error) {
     core.setFailed(error.message);
   }