Add HTML coverage report to MetaMask bot comment (#10061)

The HTML code coverage report generated by `nyc` is now included in the
MetaMask bot comment. It has been saved as an artifact on CircleCI.

.circleci/config.yml

@@ -395,6 +395,9 @@ jobs:
       - store_artifacts:
           path: builds
           destination: builds
+      - store_artifacts:
+          path: coverage
+          destination: coverage
       - store_artifacts:
           path: test-artifacts
           destination: test-artifacts

development/metamaskbot-build-announce.js

@@ -55,6 +55,9 @@ async function start() {
     })
     .join(', ')
 
+  const coverageUrl = `${BUILD_LINK_BASE}/coverage/index.html`
+  const coverageLink = `<a href="${coverageUrl}">Report</a>`
+
   // links to bundle browser builds
   const depVizUrl = `${BUILD_LINK_BASE}/build-artifacts/deps-viz/background/index.html`
   const depVizLink = `<a href="${depVizUrl}">background</a>`
@@ -65,6 +68,7 @@ async function start() {
   const contentRows = [
     `builds: ${buildLinks}`,
     `bundle viz: ${bundleLinks}`,
+    `code coverage: ${coverageLink}`,
     `dep viz: ${depVizLink}`,
     `<a href="${allArtifactsUrl}">all artifacts</a>`,
   ]