maintainers/scripts/update.nix: support auto-committing by passing attrPath

Instead of having the updateScript support returning JSON object,
it should be sufficient to specify attrPath in passthru.updateScript.
It is much easier to use.

The former is now considered experimental.

4 files changed, 36 insertions, 9 deletions

diff --git a/doc/stdenv/stdenv.xml b/doc/stdenv/stdenv.xml
index ccf5bb440d3..060dc80c915 100644
--- a/doc/stdenv/stdenv.xml
+++ b/doc/stdenv/stdenv.xml
@@ -475,11 +475,12 @@ passthru.updateScript = writeScript "update-zoom-us" ''
 <programlisting>
 passthru.updateScript = [ ../../update.sh pname "--requested-release=unstable" ];
 </programlisting>
-      Finally, the attribute can be an attribute set, listing the extra supported features among other things.
+      Finally, the attribute can be an attribute set, listing the attribute path and extra supported features in addition to command.
 <programlisting>
 passthru.updateScript = {
   command = [ ../../update.sh pname ];
-  supportedFeatures = [ "commit" ];
+  attrPath = pname;
+  supportedFeatures = [ … ];
 };
 </programlisting>
       <note>
@@ -488,9 +489,12 @@ passthru.updateScript = {
        </para>
       </note>
      </para>
+     <para>
+       <filename>maintainers/scripts/update.nix</filename> also supports automatically creating commits by running it with <literal>--argstr commit true</literal> but it requires either declaring the <variable>attrPath</variable>, or adding a <literal>commit</literal> to <variable>supportedFeatures</variable> and <link xlink:href="#var-passthru-updateScript-commit">modifying the script accordingly</link>.
+     </para>
      <variablelist>
       <title>Supported features</title>
-      <varlistentry>
+      <varlistentry xml:id="var-passthru-updateScript-commit">
        <term>
         <varname>commit</varname>
        </term>
diff --git a/maintainers/scripts/update.nix b/maintainers/scripts/update.nix
index e11e2450bd0..3d6f3500f5c 100755
--- a/maintainers/scripts/update.nix
+++ b/maintainers/scripts/update.nix
@@ -143,8 +143,10 @@ let
   packageData = package: {
     name = package.name;
     pname = lib.getName package;
+    oldVersion = lib.getVersion package;
     updateScript = map builtins.toString (lib.toList (package.updateScript.command or package.updateScript));
     supportedFeatures = package.updateScript.supportedFeatures or [];
+    attrPath = package.updateScript.attrPath or null;
   };
 
   packagesJson = pkgs.writeText "packages.json" (builtins.toJSON (map packageData packages));
diff --git a/maintainers/scripts/update.py b/maintainers/scripts/update.py
index 51a19164a17..bca554a5d82 100644
--- a/maintainers/scripts/update.py
+++ b/maintainers/scripts/update.py
@@ -72,8 +72,7 @@ def make_worktree() -> Generator[Tuple[str, str], None, None]:
         subprocess.run(['git', 'worktree', 'remove', '--force', target_directory])
         subprocess.run(['git', 'branch', '-D', branch_name])
 
-async def commit_changes(merge_lock: asyncio.Lock, worktree: str, branch: str, update_info: str) -> None:
-    changes = json.loads(update_info)
+async def commit_changes(name: str, merge_lock: asyncio.Lock, worktree: str, branch: str, changes: List[Dict]) -> None:
     for change in changes:
         # Git can only handle a single index operation at a time
         async with merge_lock:
@@ -85,7 +84,29 @@ async def commit_changes(merge_lock: asyncio.Lock, worktree: str, branch: str, u
 async def merge_changes(merge_lock: asyncio.Lock, package: Dict, update_info: str, temp_dir: Optional[Tuple[str, str]]) -> None:
     if temp_dir is not None:
         worktree, branch = temp_dir
-        await commit_changes(merge_lock, worktree, branch, update_info)
+
+        if 'commit' in package['supportedFeatures']:
+            changes = json.loads(update_info)
+        elif 'attrPath' in package:
+            attr_path = package['attrPath']
+            obtain_new_version_process = await check_subprocess('nix-instantiate', '--expr', f'with import ./. {{}}; lib.getVersion {attr_path}', '--eval', '--strict', '--json', stdout=asyncio.subprocess.PIPE, stderr=asyncio.subprocess.PIPE, cwd=worktree)
+            new_version = json.loads((await obtain_new_version_process.stdout.read()).decode('utf-8'))
+            changed_files_process = await check_subprocess('git', 'diff', '--name-only', stdout=asyncio.subprocess.PIPE, cwd=worktree)
+            changed_files = (await changed_files_process.stdout.read()).splitlines()
+            if len(changed_files) > 0:
+                changes = [
+                    {
+                        'files': changed_files,
+                        'oldVersion': package['oldVersion'],
+                        'newVersion': new_version,
+                        'attrPath': attr_path,
+                    }
+                ]
+            else:
+                changes = []
+
+        await commit_changes(package['name'], merge_lock, worktree, branch, changes)
+
     eprint(f" - {package['name']}: DONE.")
 
 async def updater(temp_dir: Optional[Tuple[str, str]], merge_lock: asyncio.Lock, packages_to_update: asyncio.Queue[Optional[Dict]], keep_going: bool, commit: bool):
@@ -95,7 +116,7 @@ async def updater(temp_dir: Optional[Tuple[str, str]], merge_lock: asyncio.Lock,
             # A sentinel received, we are done.
             return
 
-        if not ('commit' in package['supportedFeatures']):
+        if not ('commit' in package['supportedFeatures'] or 'attrPath' in package):
             temp_dir = None
 
         await run_update_script(merge_lock, temp_dir, package, keep_going)
diff --git a/pkgs/desktops/gnome-3/update.nix b/pkgs/desktops/gnome-3/update.nix
index 78cefdd0b0a..5c3e5c24785 100644
--- a/pkgs/desktops/gnome-3/update.nix
+++ b/pkgs/desktops/gnome-3/update.nix
@@ -21,9 +21,9 @@ let
     version_policy="$3"
     PATH=${lib.makeBinPath [ common-updater-scripts python ]}
     latest_tag=$(python "${./find-latest-version.py}" "$package_name" "$version_policy" "stable" ${upperBoundFlag})
-    update-source-version "$attr_path" "$latest_tag" --print-changes
+    update-source-version "$attr_path" "$latest_tag"
   '';
 in {
   command = [ updateScript packageName attrPath versionPolicy ];
-  supportedFeatures = [ "commit" ];
+  inherit attrPath;
 }