add basic test coverage for codecov score calculation

package.json

@@ -7,7 +7,7 @@
     "lint": "eslint .",
     "build": "ncc build src/index.js -o dist --license licenses.txt",
     "local": "act public --eventpath .github/workflows/local/event.json --secret-file .github/workflows/local/.env --platform ubuntu-latest=node:20-buster",
-    "test:mocha": "mocha --config .mocharc.json test/*-test.js",
+    "test:mocha": "mocha --config .mocharc.json test/*-test.js test/**/*-test.js",
     "test": "npm run lint && c8 npm run test:mocha"
   },
   "repository": {

src/score_components/coverage.js

@@ -7,7 +7,7 @@ const RETRY_DELAY = 10000;
  * @description Compiles the health score components
  * @param {import('@actions/core')} core `@actions/core` GitHub Actions core helper utility
  * @param {import('@actions/github')} github `@actions/github` GitHub Actions core helper utility
- * @returns {number} Number of uncovered lines of code, or 0 in the case of no codecov token specified
+ * @returns {Promise<number>} Number of uncovered lines of code, or 0 in the case of no codecov token specified
  */
 module.exports = async function retrieveCodeCoverage(core, github) {
   // See if we can get a coverage overview for this commit from codecov
@@ -28,7 +28,7 @@ module.exports = async function retrieveCodeCoverage(core, github) {
           repo_name: ctx.repo.repo,
           commitid: sha,
         });
-        // core.info(`codecov api response: ${JSON.stringify(coverage, null, 2)}`);
+        core.debug(`codecov api response: ${JSON.stringify(coverage, null, 2)}`);
         if (coverage && coverage.data) {
           if (coverage.data.totals && coverage.data.totals.misses) {
             misses = coverage.data.totals.misses;

test/score_components/coverage-test.js

@@ -0,0 +1,50 @@
+const { assert } = require('chai');
+const sinon = require('sinon');
+const core = require('@actions/core');
+const github = require('@actions/github');
+const codecov = require('@api/codecov');
+const cov = require('../../src/score_components/coverage');
+
+describe('score component: code coverage', () => {
+  const fakeCore = sinon.stub(core);
+  const fakeGithub = sinon.stub(github);
+  const fakeCodecov = sinon.stub(codecov);
+  const originalGithubContext = fakeGithub.context;
+  beforeEach(() => {
+    sinon.reset();
+    fakeCore.info.callsFake(console.log);
+    fakeCore.error.callsFake(console.error);
+    fakeGithub.context = originalGithubContext;
+  });
+
+  it('should export a function', () => {
+    assert.isFunction(cov);
+  });
+  it('should return 0 if no `codecov_token` input provided', async () => {
+    fakeCore.getInput.withArgs('codecov_token').returns(null);
+    const res = await cov(fakeCore, fakeGithub);
+    assert.equal(res, 0);
+  });
+  it('should return total number of missed lines from codecov API response', async () => {
+    fakeCore.getInput.withArgs('codecov_token').returns('abcd1234');
+    fakeGithub.context = {
+      eventName: 'pull_request',
+      payload: {
+        after: 'abcd1234',
+      },
+      repo: {
+        owner: 'slackapi',
+        repo: 'slack-health-score',
+      },
+    };
+    fakeCodecov.repos_commits_retrieve.resolves({
+      data: {
+        totals: {
+          misses: 1337,
+        },
+      },
+    });
+    const res = await cov(fakeCore, fakeGithub);
+    assert.equal(res, 1337);
+  });
+});