dx: include test results in comment (#230)

Author: adampash

Diff for: .gitignore

@@ -10,3 +10,4 @@ dist/mercury_test.js
 dist/mercury_test.js.map
 dist/mercury_test.web.js
 tmp/artifacts
+test-output.json

Diff for: package.json

@@ -16,7 +16,7 @@
     "build:generator": "rollup -c scripts/rollup.config.js",
     "test_build": "rollup -c",
     "test": "yarn test:node && yarn test:web",
-    "test:node": "jest",
+    "test:node": "jest --json --outputFile test-output.json",
     "test:web": "node ./node_modules/karma/bin/karma start karma.conf.js --auto-watch",
     "test:build": "cd ./scripts && jest check-build.test.js",
     "test:build:web": "node ./scripts/proxy-browser-test.js",

Diff for: scripts/comment-on-pr.js

@@ -2,6 +2,7 @@
 const bot = require('@jesses/circle-github-bot').default.create();
 const Mercury = require('../dist/mercury.js');
 const fs = require('fs');
+const getTestReport = require('./get-test-report');
 
 const run = () => {
   const screenshotPath = process.argv[2];
@@ -34,6 +35,9 @@ const run = () => {
         fs.writeFileSync(jsonPath, JSON.stringify(json));
         fs.writeFileSync(fixtureArtifactPath, html);
 
+        const testReport =
+          getTestReport('./test-output.json') || '✅ All tests passed';
+
         bot.comment(
           process.env.GH_AUTH_TOKEN,
           `### 🤖 Automated Parsing Preview 🤖
@@ -63,8 +67,10 @@ ${JSON.stringify(json, null, 2)}
 
 ${Object.keys(json)
             .map(key => (json[key] !== null ? '' : `  * \`${key}\n\``))
-            .join('') || 'None'}
+            .join('\n\n') || 'None'}
+
 
+${testReport}
 `
         );
       });

Diff for: scripts/get-test-report.js

@@ -0,0 +1,56 @@
+const fs = require('fs');
+
+const getTestReport = path => {
+  try {
+    const testReport = JSON.parse(fs.readFileSync(path));
+    const { numFailedTests } = testReport;
+    if (numFailedTests === 0) {
+      return false;
+    }
+    const { testResults } = testReport;
+    const failedTests = testResults
+      .map(({ assertionResults }) =>
+        assertionResults.filter(({ status }) => status !== 'passed')
+      )
+      .reduce((acc, arr) => acc.concat(arr));
+
+    const failureReport = `
+<details>
+<summary>
+<b>${numFailedTests} failed tests 😱</b>
+</summary>
+
+---
+
+${failedTests
+      .map(
+        ({ fullName, failureMessages }) =>
+          `
+**${fullName}**
+
+  <details>
+  <summary>
+    See what went wrong
+  </summary>
+
+\`\`\`bash
+  ${failureMessages.join('\n\n')}
+\`\`\`
+
+  </details>
+
+---
+  `
+      )
+      .join('\n\n')}
+
+</details>
+  `;
+    return failureReport;
+  } catch (e) {
+    console.log('Error generating test report', e);
+    return false;
+  }
+};
+
+module.exports = getTestReport;