build: move breaking changes script away from gulp

package.json

@@ -24,7 +24,7 @@
     "e2e": "bazel test //src/... --test_tag_filters=e2e",
     "deploy": "echo 'Not supported yet. Tracked with COMP-230'",
     "webdriver-manager": "webdriver-manager",
-    "breaking-changes": "gulp breaking-changes",
+    "breaking-changes": "ts-node --project scripts scripts/breaking-changes.ts",
     "gulp": "gulp",
     "stage-release": "ts-node --project tools/release/ tools/release/stage-release.ts",
     "publish-release": "ts-node --project tools/release/ tools/release/publish-release.ts",

scripts/breaking-changes.ts

@@ -0,0 +1,104 @@
+import {join, relative} from 'path';
+import {readFileSync} from 'fs';
+import {bold, red, green} from 'chalk';
+import * as ts from 'typescript';
+import * as tsutils from 'tsutils';
+
+const projectRoot = process.cwd();
+
+// Current version from the package.json. Splits it on the dash to ignore pre-release labels.
+const packageVersion = require(join(projectRoot, 'package.json')).version.split('-')[0];
+
+// Regex used to extract versions from a string.
+const versionRegex = /\d+\.\d+\.\d+/;
+
+// Goes through all of the TypeScript files in the project and puts
+// together a summary of all of the pending and expired breaking changes.
+const configFile = ts.readJsonConfigFile(join(projectRoot, 'tsconfig.json'), ts.sys.readFile);
+const parsedConfig = ts.parseJsonSourceFileConfigFileContent(configFile, ts.sys, projectRoot);
+const summary: {[version: string]: string[]} = {};
+
+// Go through all the TS files in the project.
+parsedConfig.fileNames.forEach(fileName => {
+  const sourceFile = ts.createSourceFile(fileName, readFileSync(fileName, 'utf8'),
+      configFile.languageVersion);
+  const lineRanges = tsutils.getLineRanges(sourceFile);
+
+  // Go through each of the comments of the file.
+  tsutils.forEachComment(sourceFile, (file, range) => {
+    const comment = file.substring(range.pos, range.end);
+    const versionMatch = comment.match(versionRegex);
+
+    // Don't do any extra work if the comment doesn't indicate a breaking change.
+    if (!versionMatch || comment.indexOf('@breaking-change') === -1) {
+      return;
+    }
+
+    // Use a path relative to the project root, in order to make the summary more tidy.
+    // Also replace escaped Windows slashes with regular forward slashes.
+    const pathInProject = relative(projectRoot, sourceFile.fileName).replace(/\\/g, '/');
+    const [version] = versionMatch;
+
+    summary[version] = summary[version] || [];
+    summary[version].push(`  ${pathInProject}: ${formatMessage(comment, range, lineRanges)}`);
+  });
+});
+
+// Go through the summary and log out all of the breaking changes.
+Object.keys(summary).forEach(version => {
+  const isExpired = hasExpired(packageVersion, version);
+  const status = isExpired ? red('(expired)') : green('(not expired)');
+  const header = bold(`Breaking changes for ${version} ${status}:`);
+  const messages = summary[version].join('\n');
+
+  console.log(isExpired ? red(header) : header);
+  console.log(isExpired ? red(messages) : messages, '\n');
+});
+
+/**
+ * Formats a message to be logged out in the breaking changes summary.
+ * @param comment Contents of the comment that contains the breaking change.
+ * @param commentRange Object containing info on the position of the comment in the file.
+ * @param lines Ranges of the lines of code in the file.
+ */
+function formatMessage(comment: string, commentRange: ts.CommentRange, lines: tsutils.LineRange[]) {
+  const lineNumber = lines.findIndex(line => line.pos > commentRange.pos);
+  const messageMatch = comment.match(/@deprecated(.*)|@breaking-change(.*)/);
+  const message = messageMatch ? messageMatch[0] : '';
+  const cleanMessage = message
+    .replace(/[\*\/\r\n]|@[\w-]+/g, '')
+    .replace(versionRegex, '')
+    .trim();
+
+  return `Line ${lineNumber}, ${cleanMessage || 'No message'}`;
+}
+
+
+/** Converts a version string into an object. */
+function parseVersion(version: string) {
+  const [major = 0, minor = 0, patch = 0] = version.split('.').map(segment => parseInt(segment));
+  return {major, minor, patch};
+}
+
+
+/**
+ * Checks whether a version has expired, based on the current version.
+ * @param currentVersion Current version of the package.
+ * @param breakingChange Version that is being checked.
+ */
+function hasExpired(currentVersion: string, breakingChange: string) {
+  if (currentVersion === breakingChange) {
+    return true;
+  }
+
+  const current = parseVersion(currentVersion);
+  const target = parseVersion(breakingChange);
+
+  return target.major < current.major ||
+        (target.major === current.major && target.minor < current.minor) ||
+        (
+          target.major === current.major &&
+          target.minor === current.minor &&
+          target.patch < current.patch
+        );
+}

scripts/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "compilerOptions": {
+    "lib": ["es2016"],
+    "types": ["node"],
+    "strictNullChecks": true
+  }
+}

tools/gulp/gulpfile.ts

@@ -21,7 +21,6 @@ createPackageBuildTasks(momentAdapterPackage);
 createPackageBuildTasks(youTubePlayerPackage);
 createPackageBuildTasks(googleMapsPackage);
 
-import './tasks/breaking-changes';
 import './tasks/ci';
 import './tasks/clean';
 import './tasks/default';