other: Add commit message check in danger

dangerfile.js

@@ -2,8 +2,26 @@ const { danger, warn, fail } = require('danger');
 const fs = require('fs');
 
 // The Danger DSL can be a bit verbose, so let's rename
-const modified = danger.git.modified_files
+const modified = danger.git.modified_files;
+const commits = danger.git.commits;
 
+const mdTableGen = (headers, rows) => {
+
+  const headerStr = `|${headers.join('|')}|`;
+  const temp = [];
+
+  for(let i = 0; i < headers.length; i++) {
+    temp.push('---');
+  }
+
+  const splitterStr = `|${temp.join('|')}|`;
+
+  const rowStr = rows.map(row => {
+    return `|${row.join('|')}|`;
+  }).join('\n');
+
+  return `${headerStr}\n${splitterStr}\n${rowStr}\n`;
+};
 // No PR is too small to include a description of why you made a change
 
 if (danger.github.pr.body.length < 10) {
@@ -15,15 +33,33 @@ const modifiedTestFiles = modified.filter(filePath => {
   return filePath.match(/test\/.+?\.(js|jsx|ts|tsx)$/);
 });
 
-const testFilesIncludeExclusion = modifiedTestFiles.reduce((acc, value) => {
-  const content = fs.readFileSync(value).toString();
+const testFilesIncludeExclusion = modifiedTestFiles.reduce((acc, filePath) => {
+  const content = fs.readFileSync(filePath).toString();
   const invalid = content.match(/it.only|describe.only/);
   if (invalid) {
-    acc.push(value);
+    acc.push(filePath);
   }
   return acc;
 }, []);
 
 if (testFilesIncludeExclusion.length > 0) {
   fail(`An \`only\` was left in tests (${testFilesIncludeExclusion})`);
 }
+
+// Validate if commit message in PR conforms conventional change log, notify if it doesn't
+const invalidCommits = commits.reduce((acc, commit) => {
+  const invalid = !commit.message.match(/(breaking|build|ci|chore|docs|feat|fix|other|perf|refactor|revert|style|test)\:\s(.+)/);
+  if (invalid) {
+    // acc.push(`| ${commit.sha.substr(0, 7)} | ${commit.message} |\n`);
+    acc.push([
+      commit.sha.substr(0, 7),
+      commit.message
+    ]);
+  }
+  return acc;
+}, []);
+
+if (invalidCommits.length > 0) {
+  warn(`There are invalid Commits: \n\n${mdTableGen(['sha', 'commit'], invalidCommits)}`);
+}
+