Adding .git/SQUASH_MSG detection to commit message autofill

extensions/git/src/git.ts

@@ -1939,6 +1939,17 @@ export class Repository {
 		return message.replace(/^\s*#.*$\n?/gm, '').trim();
 	}
 
+	async getSquashMessage(): Promise<string | undefined> {
+		const squashMsgPath = path.join(this.repositoryRoot, '.git', 'SQUASH_MSG');
+
+		try {
+			const raw = await fs.readFile(squashMsgPath, 'utf8');
+			return this.stripCommitMessageComments(raw);
+		} catch {
+			return undefined;
+		}
+	}
+
 	async getMergeMessage(): Promise<string | undefined> {
 		const mergeMsgPath = path.join(this.repositoryRoot, '.git', 'MERGE_MSG');
 

extensions/git/src/repository.ts

@@ -866,9 +866,12 @@ export class Repository implements Disposable {
 
 	async getInputTemplate(): Promise<string> {
 		const mergeMessage = await this.repository.getMergeMessage();
+		const squashMessage = await this.repository.getSquashMessage();
 
 		if (mergeMessage) {
 			return mergeMessage;
+		} else if (squashMessage) {
+			return squashMessage;
 		}
 
 		return await this.repository.getCommitTemplate();