Swallow "remote not found" error on git before 2.30 (#514)

Git 2.30.0 introduced a dedicated exit code (2) for when `git remote rm`
failed because the remote does not exist. Earlier versions of git
always returned code 128, and only parsing stderr could tell the error
conditions apart.

Support all versions of git by checking for both exit code 2, and exit
code 128 with the specific error message. The exit code 2 check remains
more robust against localized output, hence it's kept in addition to the
output parsing path that was removed in #505.

Fixes #509

src/lib/git.test.ts

@@ -364,9 +364,9 @@ describe('deleteRemote', () => {
     repoName: 'kibana',
   } as ValidConfigOptions;
 
-  it('should swallow "no such remote" error', async () => {
+  it('should swallow "no such remote" error on git before 2.30.0', async () => {
     const err = new childProcess.SpawnError({
-      code: 2,
+      code: 128,
       cmdArgs: [],
       stdout: '',
       stderr: "fatal: No such remote: 'my-remote'\n",
@@ -376,11 +376,23 @@ describe('deleteRemote', () => {
     await expect(await deleteRemote(options, remoteName)).toBe(undefined);
   });
 
-  it('should swallow "no such remote" error, even if it is not in English', async () => {
+  it('should swallow "no such remote" error on git 2.30.0 or later', async () => {
     const err = new childProcess.SpawnError({
       code: 2,
       cmdArgs: [],
       stdout: '',
+      stderr: "fatal: No such remote: 'my-remote'\n",
+    });
+
+    jest.spyOn(childProcess, 'spawnPromise').mockRejectedValueOnce(err);
+    await expect(await deleteRemote(options, remoteName)).toBe(undefined);
+  });
+
+  it('should swallow "no such remote" error on git 2.30.0+, even if it is not in English', async () => {
+    const err = new childProcess.SpawnError({
+      code: 2, // returned only by git 2.30.0 or later, earlier versions returned 128
+      cmdArgs: [],
+      stdout: '',
       stderr: "Fehler: Remote-Repository nicht gefunden: 'my-remote'\n",
     });
 

src/lib/git.ts

@@ -191,10 +191,15 @@ export async function deleteRemote(
   } catch (e) {
     const isSpawnError = e instanceof SpawnError;
 
-    // Swallow the "remote does not exist" failure, indicated by a return
-    // code of 2. From `git help remote`: "When subcommands such as add, rename,
-    // and remove can’t find the remote in question, the exit status is 2."
-    if (isSpawnError && e.context.code == 2) {
+    // Swallow the "remote does not exist" failure.
+    // Since git 2.30.0, this failure is indicated by the specific exit code 2.
+    // In earlier versions, the exit code is 128 and only the error message can
+    // tell the problems apart.
+    if (
+      isSpawnError &&
+      (e.context.code == 2 ||
+        (e.context.code == 128 && e.context.stderr.includes('No such remote')))
+    ) {
       return;
     }