From 25397da3bf3d1c2155d7a6bf6a53c854ace4c88c Mon Sep 17 00:00:00 2001
From: Elliot Winkler <elliot.winkler@gmail.com>
Date: Mon, 10 Oct 2022 17:06:38 -0600
Subject: [PATCH] Fix hasChangesInDirectorySinceGitTag

To determine whether a package needs a new release, we ask if there have
been any new commits that contain changes to any of the files within
that package. In other words, we run a `git diff` on the repo and look
for any files that match that package.

The problem is that `git diff` returns partial file paths, that is, file
paths which are relative to the repository directory, whereas the
subdirectory path that `hasChangesInDirectorySinceGitTag` takes is an
absolute path. So when we look for matching packages we always come up
short. This confuses the tool because it doesn't think there are any new
changes to release.
---
 src/repo.test.ts |  7 ++-----
 src/repo.ts      | 14 +++++++++-----
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/repo.test.ts b/src/repo.test.ts
index aad954d5..517ad080 100644
--- a/src/repo.test.ts
+++ b/src/repo.test.ts
@@ -175,10 +175,7 @@ describe('repo', () => {
         .calledWith('git', ['diff', 'v1.0.0', 'HEAD', '--name-only'], {
           cwd: '/path/to/repo',
         })
-        .mockResolvedValue([
-          '/path/to/repo/file1',
-          '/path/to/repo/subdirectory/file1',
-        ]);
+        .mockResolvedValue(['file1', 'subdirectory/file1']);
 
       const hasChanges = await hasChangesInDirectorySinceGitTag(
         '/path/to/repo',
@@ -194,7 +191,7 @@ describe('repo', () => {
         .calledWith('git', ['diff', 'v2.0.0', 'HEAD', '--name-only'], {
           cwd: '/path/to/repo',
         })
-        .mockResolvedValue(['/path/to/repo/file1', '/path/to/repo/file2']);
+        .mockResolvedValue(['file1', 'file2']);
 
       const hasChanges = await hasChangesInDirectorySinceGitTag(
         '/path/to/repo',
diff --git a/src/repo.ts b/src/repo.ts
index a2488a33..2741101e 100644
--- a/src/repo.ts
+++ b/src/repo.ts
@@ -1,3 +1,4 @@
+import path from 'path';
 import {
   runCommand,
   getStdoutFromCommand,
@@ -112,11 +113,14 @@ async function getFilesChangedSince(
   repositoryDirectoryPath: string,
   tagName: string,
 ): Promise<string[]> {
-  return await getLinesFromGitCommandWithin(repositoryDirectoryPath, 'diff', [
-    tagName,
-    'HEAD',
-    '--name-only',
-  ]);
+  const partialFilePaths = await getLinesFromGitCommandWithin(
+    repositoryDirectoryPath,
+    'diff',
+    [tagName, 'HEAD', '--name-only'],
+  );
+  return partialFilePaths.map((partialFilePath) =>
+    path.join(repositoryDirectoryPath, partialFilePath),
+  );
 }
 
 /**