feat(ng-dev/release): add marker between generated changelog entries

ng-dev/release/notes/BUILD.bazel

@@ -1,10 +1,11 @@
-load("//tools:defaults.bzl", "ts_library")
+load("//tools:defaults.bzl", "jasmine_node_test", "ts_library")
 
 ts_library(
     name = "notes",
-    srcs = glob([
-        "**/*.ts",
-    ]),
+    srcs = glob(
+        ["**/*.ts"],
+        exclude = ["**/*.spec.ts"],
+    ),
     visibility = [
         "//ng-dev:__subpackages__",
         "//tools/local-actions/changelog/lib:__subpackages__",
@@ -23,3 +24,22 @@ ts_library(
         "@npm//semver",
     ],
 )
+
+ts_library(
+    name = "test_lib",
+    testonly = True,
+    srcs = glob(["**/*.spec.ts"]),
+    deps = [
+        ":notes",
+        "//ng-dev/release/publish/test:test_lib",
+        "//ng-dev/utils",
+        "//ng-dev/utils/testing",
+        "@npm//@types/semver",
+        "@npm//semver",
+    ],
+)
+
+jasmine_node_test(
+    name = "test",
+    specs = [":test_lib"],
+)

ng-dev/release/notes/changelog.spec.ts

@@ -0,0 +1,117 @@
+import {existsSync, readFileSync} from 'fs';
+import {SemVer} from 'semver';
+import {dedent} from '../../utils/testing/dedent';
+import {getMockGitClient} from '../publish/test/test-utils/git-client-mock';
+import {Changelog, splitMarker} from './changelog';
+
+describe('Changelog', () => {
+  let changelog: Changelog;
+
+  beforeEach(() => {
+    const gitClient = getMockGitClient(
+      {owner: 'angular', name: 'dev-infra-test', mainBranchName: 'main'},
+      /* useSandboxGitClient */ false,
+    );
+    changelog = new Changelog(gitClient);
+  });
+
+  it('throws an error if it cannot find the anchor containing the version for an entry', () => {
+    expect(() => changelog.prependEntryToChangelog('does not have version <a> tag')).toThrow();
+  });
+
+  it('throws an error if it cannot determine the version for an entry', () => {
+    expect(() => changelog.prependEntryToChangelog(createChangelogEntry('NotSemVer'))).toThrow();
+  });
+
+  it('concatenates the changelog entries into the changelog file with the split marker between', () => {
+    changelog.prependEntryToChangelog(createChangelogEntry('1.0.0'));
+    changelog.prependEntryToChangelog(createChangelogEntry('2.0.0'));
+    changelog.prependEntryToChangelog(createChangelogEntry('3.0.0'));
+
+    expect(readFileAsString(changelog.filePath)).toBe(
+      dedent`
+    <a name="3.0.0"></a>
+
+    ${splitMarker}
+
+    <a name="2.0.0"></a>
+
+    ${splitMarker}
+
+    <a name="1.0.0"></a>
+    `.trim(),
+    );
+
+    changelog.moveEntriesPriorToVersionToArchive(new SemVer('3.0.0'));
+
+    expect(readFileAsString(changelog.archiveFilePath)).toBe(
+      dedent`
+    <a name="2.0.0"></a>
+
+    ${splitMarker}
+
+    <a name="1.0.0"></a>
+    `.trim(),
+    );
+
+    expect(readFileAsString(changelog.filePath)).toBe(`<a name="3.0.0"></a>`);
+  });
+
+  describe('adds entries to the changelog', () => {
+    it('creates a new changelog file if one does not exist.', () => {
+      expect(existsSync(changelog.filePath)).toBe(false);
+
+      changelog.prependEntryToChangelog(createChangelogEntry('0.0.0'));
+      expect(existsSync(changelog.filePath)).toBe(true);
+    });
+
+    it('should not include a split marker when only one changelog entry is in the changelog.', () => {
+      changelog.prependEntryToChangelog(createChangelogEntry('0.0.0'));
+
+      expect(readFileAsString(changelog.filePath)).not.toContain(splitMarker);
+    });
+
+    it('separates multiple changelog entries using a standard split marker', () => {
+      for (let i = 0; i < 2; i++) {
+        changelog.prependEntryToChangelog(createChangelogEntry(`0.0.${i}`));
+      }
+
+      expect(readFileAsString(changelog.filePath)).toContain(splitMarker);
+    });
+  });
+
+  describe('adds entries to the changelog archive', () => {
+    it('only updates or creates the changelog archive if necessary', () => {
+      changelog.prependEntryToChangelog(createChangelogEntry('1.0.0'));
+      expect(existsSync(changelog.archiveFilePath)).toBe(false);
+
+      changelog.moveEntriesPriorToVersionToArchive(new SemVer('1.0.0'));
+      expect(existsSync(changelog.archiveFilePath)).toBe(false);
+
+      changelog.moveEntriesPriorToVersionToArchive(new SemVer('2.0.0'));
+      expect(existsSync(changelog.archiveFilePath)).toBe(true);
+    });
+
+    it('from the primary changelog older than a provided version', () => {
+      changelog.prependEntryToChangelog(createChangelogEntry('1.0.0', 'This is version 1'));
+      changelog.prependEntryToChangelog(createChangelogEntry('2.0.0', 'This is version 2'));
+      changelog.prependEntryToChangelog(createChangelogEntry('3.0.0', 'This is version 3'));
+
+      changelog.moveEntriesPriorToVersionToArchive(new SemVer('3.0.0'));
+      expect(readFileAsString(changelog.archiveFilePath)).toContain('version 1');
+      expect(readFileAsString(changelog.archiveFilePath)).toContain('version 2');
+      expect(readFileAsString(changelog.archiveFilePath)).not.toContain('version 3');
+    });
+  });
+});
+
+function readFileAsString(file: string) {
+  return readFileSync(file, {encoding: 'utf8'});
+}
+
+function createChangelogEntry(version: string, content = '') {
+  return dedent`
+    <a name="${version}"></a>
+    ${content}
+    `;
+}

ng-dev/release/notes/changelog.ts

@@ -0,0 +1,142 @@
+import {existsSync, readFileSync, writeFileSync} from 'fs';
+import {join} from 'path';
+import * as semver from 'semver';
+import {GitClient} from '../../utils/git/git-client';
+
+/** Project-relative path for the changelog file. */
+export const changelogPath = 'CHANGELOG.md';
+
+/** Project-relative path for the changelog archive file. */
+export const changelogArchivePath = 'CHANGELOG_ARCHIVE.md';
+
+/** A marker used to split a CHANGELOG.md file into individual entries. */
+export const splitMarker = '<!-- CHANGELOG SPLIT MARKER -->';
+
+/**
+ * A string to use between each changelog entry when joining them together.
+ *
+ * Since all every changelog entry's content is trimmed, when joining back together, two new lines
+ * must be placed around the splitMarker to create a one line buffer around the comment in the
+ * markdown.
+ * i.e.
+ * <changelog entry content>
+ *
+ * <!-- CHANGELOG SPLIT MARKER -->
+ *
+ * <changelog entry content>
+ */
+const joinMarker = `\n\n${splitMarker}\n\n`;
+
+/** A RegExp matcher to extract the version of a changelog entry from the entry content. */
+const versionAnchorMatcher = new RegExp(`<a name="(.*)"></a>`);
+
+/** An individual changelog entry. */
+interface ChangelogEntry {
+  content: string;
+  version: semver.SemVer;
+}
+
+export class Changelog {
+  /** The absolute path to the changelog file. */
+  readonly filePath = join(this.git.baseDir, changelogPath);
+  /** The absolute path to the changelog archive file. */
+  readonly archiveFilePath = join(this.git.baseDir, changelogArchivePath);
+  /** The changelog entries in the CHANGELOG.md file. */
+  private entries = this.getEntriesFor(this.filePath);
+  /**
+   * The changelog entries in the CHANGELOG_ARCHIVE.md file.
+   * Delays reading the CHANGELOG_ARCHIVE.md file until it is actually used.
+   */
+  private get archiveEntries() {
+    if (this._archiveEntries === undefined) {
+      return (this._archiveEntries = this.getEntriesFor(this.archiveFilePath));
+    }
+    return this._archiveEntries;
+  }
+  private _archiveEntries: undefined | ChangelogEntry[] = undefined;
+
+  constructor(private git: GitClient) {}
+
+  /** Prepend a changelog entry to the changelog. */
+  prependEntryToChangelog(entry: string) {
+    this.entries.unshift(parseChangelogEntry(entry));
+    this.writeToChangelogFile();
+  }
+
+  /**
+   * Move all changelog entries from the CHANGELOG.md file for versions prior to the provided
+   * version to the changelog archive.
+   *
+   * Versions should be used to determine which entries are moved to archive as versions are the
+   * most accurate piece of context found within a changelog entry to determine its relationship to
+   * other changelog entries.  This allows for example, moving all changelog entries out of the
+   * main changelog when a version moves out of support.
+   */
+  moveEntriesPriorToVersionToArchive(version: semver.SemVer) {
+    [...this.entries].reverse().forEach((entry: ChangelogEntry) => {
+      if (semver.lt(entry.version, version)) {
+        this.archiveEntries.unshift(entry);
+        this.entries.splice(this.entries.indexOf(entry), 1);
+      }
+    });
+
+    this.writeToChangelogFile();
+    if (this.archiveEntries.length) {
+      this.writeToChangelogArchiveFile();
+    }
+  }
+
+  /** Update the changelog archive file with the known changelog archive entries. */
+  private writeToChangelogArchiveFile(): void {
+    const changelogArchive = this.archiveEntries.map((entry) => entry.content).join(joinMarker);
+    writeFileSync(this.archiveFilePath, changelogArchive);
+  }
+
+  /** Update the changelog file with the known changelog entries. */
+  private writeToChangelogFile(): void {
+    const changelog = this.entries.map((entry) => entry.content).join(joinMarker);
+    writeFileSync(this.filePath, changelog);
+  }
+
+  /**
+   * Retrieve the changelog entries for the provide changelog path, if the file does not exist an
+   * empty array is returned.
+   */
+  private getEntriesFor(path: string): ChangelogEntry[] {
+    if (!existsSync(path)) {
+      return [];
+    }
+
+    return (
+      readFileSync(path, {encoding: 'utf8'})
+        // Use the versionMarker as the separator for .split().
+        .split(splitMarker)
+        // If the `split()` method finds the separator at the beginning or end of a string, it
+        // includes an empty string at the respective locaiton, so we filter to remove all of these
+        // potential empty strings.
+        .filter((entry) => entry.trim().length !== 0)
+        // Create a ChangelogEntry for each of the string entry.
+        .map(parseChangelogEntry)
+    );
+  }
+}
+
+/** Parse the provided string into a ChangelogEntry object. */
+function parseChangelogEntry(content: string): ChangelogEntry {
+  const versionMatcherResult = versionAnchorMatcher.exec(content);
+  if (versionMatcherResult === null) {
+    throw Error(`Unable to determine version for changelog entry: ${content}`);
+  }
+  const version = semver.parse(versionMatcherResult[1]);
+
+  if (version === null) {
+    throw Error(
+      `Unable to determine version for changelog entry, with tag: ${versionMatcherResult[1]}`,
+    );
+  }
+
+  return {
+    content: content.trim(),
+    version,
+  };
+}

ng-dev/release/notes/release-notes.ts

@@ -19,9 +19,8 @@ import changelogTemplate from './templates/changelog';
 import githubReleaseTemplate from './templates/github-release';
 import {getCommitsForRangeWithDeduping} from './commits/get-commits-in-range';
 import {getConfig} from '../../utils/config';
-import {existsSync, readFileSync, writeFileSync} from 'fs';
-import {join} from 'path';
 import {assertValidFormatConfig} from '../../format/config';
+import {Changelog} from './changelog';
 
 /** Project-relative path for the changelog file. */
 export const changelogPath = 'CHANGELOG.md';
@@ -34,8 +33,8 @@ export class ReleaseNotes {
     return new ReleaseNotes(version, commits, git);
   }
 
-  /** The absolute path to the changelog file. */
-  private changelogPath = join(this.git.baseDir, changelogPath);
+  /** The changelog writer. */
+  private changelog = new Changelog(this.git);
   /** The RenderContext to be used during rendering. */
   private renderContext: RenderContext | undefined;
   /** The title to use for the release. */
@@ -70,23 +69,15 @@ export class ReleaseNotes {
    * provided by the GitClient.
    */
   async prependEntryToChangelog() {
-    /** The changelog contents in the current changelog. */
-    let changelog = '';
-    if (existsSync(this.changelogPath)) {
-      changelog = readFileSync(this.changelogPath, {encoding: 'utf8'});
-    }
-    /** The new changelog entry to add to the changelog. */
-    const entry = await this.getChangelogEntry();
-
-    writeFileSync(this.changelogPath, `${entry}\n\n${changelog}`);
+    this.changelog.prependEntryToChangelog(await this.getChangelogEntry());
 
     // TODO(josephperrott): Remove file formatting calls.
     //   Upon reaching a standardized formatting for markdown files, rather than calling a formatter
     //   for all creation of changelogs, we instead will confirm in our testing that the new changes
     //   created for changelogs meet on standardized markdown formats via unit testing.
     try {
       assertValidFormatConfig(this.config);
-      await formatFiles([this.changelogPath]);
+      await formatFiles([this.changelog.filePath]);
     } catch {
       // If the formatting is either unavailable or fails, continue on with the unformatted result.
     }

ng-dev/release/publish/test/BUILD.bazel

@@ -5,6 +5,9 @@ ts_library(
     srcs = glob([
         "**/*.ts",
     ]),
+    visibility = [
+        "//ng-dev/release/notes:__subpackages__",
+    ],
     deps = [
         "//ng-dev/commit-message",
         "//ng-dev/release/config",

ng-dev/release/publish/test/common.spec.ts

@@ -202,7 +202,9 @@ describe('common release action logic', () => {
       expect(changelogContent).toMatch(changelogPattern`
         # 10.0.1 <..>
 
+        <!-- CHANGELOG SPLIT MARKER -->
 
+        <a name="0.0.0"></a>
         Existing changelog
       `);
     });

ng-dev/release/publish/test/release-notes/generation.spec.ts

@@ -453,18 +453,4 @@ describe('release notes generation', () => {
       `| [${shortSha}](https://github.com/angular/dev-infra-test/commit/${fullSha}) | fix | commit *1 |`,
     );
   });
-
-  it('updates the changelog file by prepending the entry to the current changelog', async () => {
-    writeFileSync(`${testTmpDir}/CHANGELOG.md`, '<Previous Changelog Entries>');
-
-    SandboxGitRepo.withInitialCommit(githubConfig).createTagForHead('startTag');
-
-    const releaseNotes = await ReleaseNotes.forRange(parse('13.0.0'), 'startTag', 'HEAD');
-    await releaseNotes.prependEntryToChangelog();
-
-    const changelog = readFileSync(`${testTmpDir}/CHANGELOG.md`, 'utf8');
-
-    const entry = await releaseNotes.getChangelogEntry();
-    expect(changelog).toBe(`${entry}\n\n<Previous Changelog Entries>`);
-  });
 });

ng-dev/release/publish/test/test-utils/action-mocks.ts

@@ -86,7 +86,7 @@ export function setupMocksForReleaseAction<T extends boolean>(
 
   // Create an empty changelog and a `package.json` file so that file system
   // interactions with the project directory do not cause exceptions.
-  writeFileSync(join(testTmpDir, 'CHANGELOG.md'), 'Existing changelog');
+  writeFileSync(join(testTmpDir, 'CHANGELOG.md'), '<a name="0.0.0"></a>\nExisting changelog');
   writeFileSync(join(testTmpDir, 'package.json'), JSON.stringify({version: '0.0.0'}));
 
   // Override the default pull request wait interval to a number of milliseconds that can be