add test of action directly, mocking @actions/core

package.json

@@ -34,6 +34,7 @@
     "esbuild": "^0.23.1",
     "eslint": "^9.9.1",
     "eslint-plugin-mocha": "^10.5.0",
+    "esmock": "^2.6.7",
     "globals": "^15.9.0",
     "mocha": "^10.7.3",
     "peggy": "^4.0.3"

src/main.mjs

@@ -1,12 +1,17 @@
-import * as core from '@actions/core';
+import core from '@actions/core';
 import { getPrereqs } from './get-prereqs.mjs';
 import { cpanmVersion, dottedVersion } from './cpan-versions.mjs';
 
 const run = async () => {
-  const phases = core.getInput('phases').split(/\s+/);
-  const relationships = core.getInput('relationships').split(/\s+/);
-  const features = core.getInput('features').split(/\s+/);
-  const sources = core.getInput('sources').split(/\s+/);
+  const phasesInput = core.getInput('phases');
+  const relationshipsInput = core.getInput('relationships');
+  const featuresInput = core.getInput('features');
+  const sourcesInput = core.getInput('sources');
+
+  const phases = new Set(phasesInput.split(/\s+/));
+  const relationships = new Set(relationshipsInput.split(/\s+/));
+  const features = new Set(featuresInput.split(/\s+/));
+  const sources = sourcesInput.split(/\s+/);
 
   const { perl, ...prereqs } = await getPrereqs({
     phases,
@@ -31,7 +36,7 @@ const run = async () => {
   core.setOutput('prereqsJSON', JSON.stringify(prereqs));
 };
 
-(async () => {
+await (async () => {
   try {
     await run();
   }

test/action.test.mjs

@@ -0,0 +1,44 @@
+import { describe, it } from 'mocha';
+import { expect } from 'chai';
+
+import { dirname, join as joinPath } from 'node:path';
+import { fileURLToPath } from 'url';
+
+import esmock from 'esmock';
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+const main = async (inputs) => {
+  const outputs = {};
+  let failed;
+  await esmock('../src/main.mjs', {
+    '@actions/core': {
+      getInput:          key => (inputs[key] || '').trim(),
+      getMultilineInput: key => (inputs[key] || '').split(/\n/).map(t => t.trim()),
+      setOutput:         (key, value) => { outputs[key] = value; },
+      setFailed:         (message) => { failed = message; },
+    },
+  });
+  if (failed) {
+    throw new Error(failed);
+  }
+  return {
+    outputs,
+  };
+};
+
+describe('GitHub action', function () {
+  it('runs', async function () {
+    const { outputs } = await main({
+      sources:       joinPath(__dirname, 'corpus', 'META.json'),
+      phases:        'test',
+      relationships: 'recommends',
+      features:      '',
+    });
+    expect(outputs).to.be.deep.equal({
+      'prereqs':            'CPAN::Meta~2.120900\n',
+      'prereqs-no-version': 'CPAN::Meta\n',
+      'prereqsJSON':        '{"CPAN::Meta":">=2.120900"}',
+    });
+  });
+});