refactor(dev-infra): set up new method for checking range of commits (#41341)

Check a range of commits by retrieving the log files to be parsed with the expected
format for the parser.

This change is in part of a larger set of changes making the process for obtaining
and parsing commits for release note creation and message validation consistent.
This consistency will make it easier to debug as well as ease the design of tooling
which is built on top of these processes.

PR Close #41341

dev-infra/commit-message/parse.ts

@@ -8,8 +8,6 @@
 
 import {Commit as ParsedCommit, Options, sync as parse} from 'conventional-commits-parser';
 
-import {exec} from '../utils/shelljs';
-
 
 /** A parsed commit, containing the information needed to validate the commit. */
 export interface Commit {
@@ -43,6 +41,30 @@ export interface Commit {
   isRevert: boolean;
 }
 
+/**
+ * A list of tuples expressing the fields to extract from each commit log entry. The tuple contains
+ * two values, the first is the key for the property and the second is the template shortcut for the
+ * git log command.
+ */
+const commitFields = {
+  hash: '%H',
+  shortHash: '%h',
+  author: '%aN',
+};
+/** The additional fields to be included in commit log entries for parsing. */
+export type CommitFields = typeof commitFields;
+/** The commit fields described as git log format entries for parsing. */
+export const commitFieldsAsFormat = (fields: CommitFields) => {
+  return Object.entries(fields).map(([key, value]) => `%n-${key}-%n${value}`).join('');
+};
+/**
+ * The git log format template to create git log entries for parsing.
+ *
+ * The conventional commits parser expects to parse the standard git log raw body (%B) into its
+ * component parts. Additionally it will parse additional fields with keys defined by
+ * `-{key name}-` separated by new lines.
+ * */
+export const gitLogFormatForParsing = `%B${commitFieldsAsFormat(commitFields)}`;
 /** Markers used to denote the start of a note section in a commit. */
 enum NoteSections {
   BREAKING_CHANGE = 'BREAKING CHANGE',
@@ -87,7 +109,9 @@ const parseOptions: Options&{notesPattern: (keywords: string) => RegExp} = {
 
 
 /** Parse a full commit message into its composite parts. */
-export function parseCommitMessage(fullText: string): Commit {
+export function parseCommitMessage(fullText: string|Buffer): Commit {
+  // Ensure the fullText symbol is a `string`, even if a Buffer was provided.
+  fullText = fullText.toString();
   /** The commit message text with the fixup and squash markers stripped out. */
   const strippedCommitMsg = fullText.replace(FIXUP_PREFIX_RE, '')
                                 .replace(SQUASH_PREFIX_RE, '')
@@ -126,30 +150,3 @@ export function parseCommitMessage(fullText: string): Commit {
     isRevert: REVERT_PREFIX_RE.test(fullText),
   };
 }
-
-/** Retrieve and parse each commit message in a provide range. */
-export function parseCommitMessagesForRange(range: string): Commit[] {
-  /** A random number used as a split point in the git log result. */
-  const randomValueSeparator = `${Math.random()}`;
-  /**
-   * Custom git log format that provides the commit header and body, separated as expected with the
-   * custom separator as the trailing value.
-   */
-  const gitLogFormat = `%s%n%n%b${randomValueSeparator}`;
-
-  // Retrieve the commits in the provided range.
-  const result = exec(`git log --reverse --format=${gitLogFormat} ${range}`);
-  if (result.code) {
-    throw new Error(`Failed to get all commits in the range:\n  ${result.stderr}`);
-  }
-
-  return result
-      // Separate the commits from a single string into individual commits.
-      .split(randomValueSeparator)
-      // Remove extra space before and after each commit message.
-      .map(l => l.trim())
-      // Remove any superfluous lines which remain from the split.
-      .filter(line => !!line)
-      // Parse each commit message.
-      .map(commit => parseCommitMessage(commit));
-}