build: generate changelog as part of staging script

package.json

@@ -23,7 +23,7 @@
     "api": "gulp api-docs",
     "breaking-changes": "gulp breaking-changes",
     "gulp": "gulp",
-    "stage-release": "bash ./tools/release/stage-release-bin.sh",
+    "stage-release": "ts-node --project tools/release/ tools/release/stage-release.ts",
     "preinstall": "node ./tools/npm/check-npm.js"
   },
   "version": "7.1.0",
@@ -78,20 +78,19 @@
     "axe-webdriverjs": "^1.1.1",
     "chalk": "^1.1.3",
     "codelyzer": "^4.5.0",
+    "conventional-changelog": "^3.0.5",
     "dgeni": "^0.4.10",
     "dgeni-packages": "^0.26.12",
     "firebase": "^5.5.2",
     "firebase-admin": "^5.0.0",
     "firebase-tools": "^4.1.0",
     "fs-extra": "^3.0.1",
-    "git-semver-tags": "^2.0.0",
     "glob": "^7.1.2",
     "gulp": "^3.9.1",
     "gulp-clean": "^0.3.2",
     "gulp-clean-css": "^3.3.1",
     "gulp-cli": "^2.0.1",
     "gulp-connect": "^5.0.0",
-    "gulp-conventional-changelog": "^1.1.3",
     "gulp-dom": "^0.9.17",
     "gulp-flatten": "^0.3.1",
     "gulp-highlight-files": "^0.0.5",
@@ -117,6 +116,7 @@
     "karma-sourcemap-loader": "^0.3.7",
     "magic-string": "^0.22.4",
     "marked": "^0.5.1",
+    "merge2": "^1.2.3",
     "minimatch": "^3.0.4",
     "minimist": "^1.2.0",
     "mock-fs": "^4.7.0",

tools/gulp/gulpfile.ts

@@ -17,7 +17,6 @@ createPackageBuildTasks(momentAdapterPackage);
 
 import './tasks/aot';
 import './tasks/breaking-changes';
-import './tasks/changelog';
 import './tasks/ci';
 import './tasks/clean';
 import './tasks/default';

tools/release/changelog.ts

@@ -0,0 +1,98 @@
+import {green, grey} from 'chalk';
+import {createReadStream, createWriteStream, readFileSync} from 'fs';
+import {prompt} from 'inquirer';
+import {join} from 'path';
+import {Readable} from 'stream';
+
+// These imports lack type definitions.
+const conventionalChangelog = require('conventional-changelog');
+const merge2 = require('merge2');
+
+/** Prompts for a changelog release name and prepends the new changelog. */
+export async function promptAndGenerateChangelog(changelogPath: string) {
+  const releaseName = await promptChangelogReleaseName();
+  await prependChangelogFromLatestTag(changelogPath, releaseName);
+}
+
+/**
+ * Writes the changelog from the latest Semver tag to the current HEAD.
+ * @param changelogPath Path to the changelog file.
+ * @param releaseName Name of the release that should show up in the changelog.
+ */
+export async function prependChangelogFromLatestTag(changelogPath: string, releaseName: string) {
+  const outputStream: Readable = conventionalChangelog(
+    /* core options */ {preset: 'angular'},
+    /* context options */ {title: releaseName},
+    /* raw-commits options */ null,
+    /* commit parser options */ null,
+    /* writer options */ createDedupeWriterOptions(changelogPath));
+
+  // Stream for reading the existing changelog. This is necessary because we want to
+  // actually prepend the new changelog to the existing one.
+  const previousChangelogStream = createReadStream(changelogPath);
+
+  return new Promise((resolve, reject) => {
+    // Sequentially merge the changelog output and the previous changelog stream, so that
+    // the new changelog section comes before the existing versions. Afterwards, pipe into the
+    // changelog file, so that the changes are reflected on file system.
+    const mergedCompleteChangelog = merge2(outputStream, previousChangelogStream);
+
+    // Wait for the previous changelog to be completely read because otherwise we would
+    // read and write from the same source which causes the content to be thrown off.
+    previousChangelogStream.on('end', () => {
+      mergedCompleteChangelog.pipe(createWriteStream(changelogPath))
+        .once('error', (error: any) => reject(error))
+        .once('finish', () => resolve());
+    });
+
+  });
+}
+
+/** Prompts the terminal for a changelog release name. */
+export async function promptChangelogReleaseName(): Promise<string> {
+  return (await prompt<{releaseName: string}>({
+    type: 'text',
+    name: 'releaseName',
+    message: 'What should be the name of the release?'
+  })).releaseName;
+}
+
+/**
+ * Creates changelog writer options which ensure that commits are not showing up multiple times.
+ * Commits can show up multiple times if a changelog has been generated on a publish branch
+ * and has been cherry-picked into "master". In that case, the changelog will already contain
+ * commits from master which might be added to the changelog again. This is because usually
+ * patch and minor releases are tagged from the publish branches and therefore
+ * conventional-changelog tries to build the changelog from last major version to master's HEAD.
+ */
+function createDedupeWriterOptions(changelogPath: string) {
+  const existingChangelogContent = readFileSync(changelogPath, 'utf8');
+
+  return {
+    // Specify a writer option that can be used to modify the content of a new changelog section.
+    // See: conventional-changelog/tree/master/packages/conventional-changelog-writer
+    finalizeContext: (context: any) => {
+      context.commitGroups.forEach((group: any) => {
+        group.commits = group.commits.filter((commit: any) => {
+          // NOTE: We cannot compare the SHA's because the commits will have a different SHA
+          // if they are being cherry-picked into a different branch.
+          if (existingChangelogContent.includes(commit.header)) {
+            console.log(grey(`Excluding: "${commit.header}" (${commit.hash})`));
+            return false;
+          }
+          return true;
+        });
+      });
+      return context;
+    }
+  };
+}
+
+/** Entry-point for generating the changelog when called through the CLI. */
+if (require.main === module) {
+  promptAndGenerateChangelog(join(__dirname, '../../CHANGELOG.md')).then(() => {
+    console.log(green('  ✓   Successfully updated the changelog.'));
+  });
+}
+
+

tools/release/prompt/new-version-prompt.ts

@@ -45,7 +45,7 @@ export async function promptForNewVersion(currentVersion: Version): Promise<Vers
     message: `What's the type of the new release?`,
     choices: versionChoices,
   }, {
-    type: 'prompt',
+    type: 'confirm',
     name: 'isPrerelease',
     message: 'Should this be a pre-release?',
     // Prompt whether this should a pre-release if the current release is not a pre-release

tools/release/stage-release.ts

@@ -2,11 +2,15 @@ import {bold, cyan, green, italic, red, yellow} from 'chalk';
 import {existsSync, readFileSync, writeFileSync} from 'fs';
 import {prompt} from 'inquirer';
 import {join} from 'path';
+import {promptAndGenerateChangelog} from './changelog';
 import {GitClient} from './git/git-client';
 import {promptForNewVersion} from './prompt/new-version-prompt';
 import {parseVersionName, Version} from './version-name/parse-version';
 import {getExpectedPublishBranch} from './version-name/publish-branch';
 
+/** Default filename for the changelog. */
+const CHANGELOG_FILE_NAME = 'CHANGELOG.md';
+
 /**
  * Class that can be instantiated in order to stage a new release. The tasks requires user
  * interaction/input through command line prompts.
@@ -92,13 +96,15 @@ class StageReleaseTask {
 
     console.log(green(`  ✓   Updated the version to "${bold(newVersionName)}" inside of the ` +
       `${italic('package.json')}`));
+    console.log();
 
-    // TODO(devversion): run changelog script w/prompts in the future.
-    // For now, we just let users make modifications and stage the changes.
+    await promptAndGenerateChangelog(join(this.projectDir, CHANGELOG_FILE_NAME));
 
-    console.log(yellow(`  ⚠   Please generate the ${bold('CHANGELOG')} for the new version. ` +
-      `You can also make other unrelated modifications. After the changes have been made, ` +
-      `just continue here.`));
+    console.log();
+    console.log(green(`  ✓   Updated the changelog in ` +
+      `"${bold(CHANGELOG_FILE_NAME)}"`));
+    console.log(yellow(`  ⚠   You can also make other unrelated modifications. After the ` +
+      `changes have been made, just continue here.`));
     console.log();
 
     const {shouldContinue} = await prompt<{shouldContinue: boolean}>({
@@ -166,19 +172,7 @@ class StageReleaseTask {
 }
 
 /** Entry-point for the release staging script. */
-async function main() {
-  const projectDir = process.argv.slice(2)[0];
-
-  if (!projectDir) {
-    console.error(red(`You specified no project directory. Cannot run stage release script.`));
-    console.error(red(`Usage: bazel run //tools/release:stage-release <project-directory>`));
-    process.exit(1);
-  }
-
-  return new StageReleaseTask(projectDir).run();
-}
-
 if (require.main === module) {
-  main();
+  new StageReleaseTask(join(__dirname, '../../')).run();
 }