View Patch

Review .patch and .diff files in one side-by-side Changes view in Visual Studio Code (VS Code). Use complete files from a Git repository, or explicitly review just the patch hunks without any repository.

The Patch Reviews panel in the Explorer keeps the repository, base, file list, and review checklist alongside the diff. The extension stays read-only and offline.

Open a patch

• Right-click a patch in the Explorer and choose Open Patch as Changes.
• Choose Open With... > View Patch (Changes). This is opt-in; installing the extension does not replace the normal text editor for patch files.
• With a patch open, use the Open Patch as Changes button in the editor title bar.
• Run View Patch: Open Patch as Changes from the Command Palette. Pasted, unsaved text also works when its editor language is Diff, and Open Patch from Clipboard skips even the paste.
• Drag patch files onto the Patch Reviews panel in the Explorer.
• Run View Patch: Open Sample Patch to try the viewer without any repository.
• Run View Patch: Review a Commit... to review any revision straight from history - no patch file at all. Merge commits show their changes versus each parent; a root commit is shown against the empty tree.

Selecting several files with the ordinary command opens independent reviews. To apply dependent patches in order, use the series command below.

Review complete files

A patch normally contains only edited lines and their surrounding context. For a complete-file review, View Patch applies it in a private scratch area and reads each file before and after the change.

The extension searches:

1. repositories in the Source Control view;
2. workspace folders;
3. the patch file's folder;
4. extra folders in viewPatch.repositories.

When a git format-patch or git show file names a commit present in one of those repositories, the base is that commit's parent. Otherwise, View Patch tries HEAD in the candidate repositories and asks when several apply. The summary shows both the requested base and its frozen snapshot tree identifier.

An open workspace folder is not required: in an empty window, the patch file's folder and viewPatch.repositories still locate the repository, and hunk-only views need none at all.

Use Open Patch as Changes on a Repository and Base..., or Change Repository and Base... on a review, to choose a repository and revision yourself.

Review hunks without a repository

Run View Patch: View Patch Hunks Only, or choose View Hunks Only when a complete-file review cannot apply. This mode needs neither Git nor workspace trust.

The title, summary, and document headers explicitly say partial context. Only lines actually present in the patch are shown, with original line ranges and omitted-context separators. Missing file contents are never invented. Binary payloads are not reconstructed; only their supplied metadata is shown.

This is an explicit choice, not a silent fallback from a failed complete-file review.

Review a patch series

• Open a mailbox containing several messages from git format-patch --stdout as an ordinary patch.
• Or select separate patch files and run View Patch: Open Selected Patches as Series.... The command also offers a multi-file picker. Numbered messages or filenames are sorted numerically; otherwise selection order is kept. Duplicate numbers are rejected rather than guessed.

Each patch is applied to the preceding patch's result in one private scratch area. Patch Reviews offers the combined result and each individual patch, including subjects and authors. Cover letters are not applied as changes. If the combined result has no net changes, the individual patches remain reviewable.

A hunk-only series shows individual messages, not a fabricated complete-file or cumulative reconstruction.

Compare two patch versions

With a complete-file review open, Compare with Another Patch... applies the current patch and a second file to the same frozen base, then opens the result difference: the first version's outcome on the left, the second version's on the right. This is how a v2 of a change differs from its v1, not a textual diff of the two patch files. Identical outcomes are reported without opening an empty review. A comparison cannot be refreshed or rebased; run the command again.

Merge commits

A combined merge diff (git show of a merge, diff --cc) is never applied as text. When the named commit exists in a known repository, View Patch shows the merge's real changes versus each parent, read from history. When the repository is not available, hunk-only mode shows explicit per-parent hunk views instead.

Mailed patches

Message bodies encoded as quoted-printable or base64 are decoded before parsing, so mailed patches with encoded diffs review normally. Unsupported encodings and multipart mail are rejected with the reason named.

Summary, checklist, and refresh

Expand Patch Reviews in the Explorer, or run View Patch: Show Patch Reviews. Expand Review Details for the selected patch's subject, author, date, snapshot identifier, and detailed counts. The panel divider can be dragged upward to give a large checklist more room.

• See the repository, base, subject, author, date, and added/modified/deleted/renamed file counts.
• Filter old and new paths with the filter button.
• Toggle each file's reviewed checkmark. Selecting a file opens its individual diff. Mark All Reviewed and Clear Reviewed Checkmarks work on the whole review, and the view's badge counts unreviewed files.
• Next/Previous Unreviewed File walk what is left; the viewPatch.markReviewedOnOpen setting checks files off as you open them.
• Copy Review Summary as Markdown copies the repository, base, file list, per-file line counts, and checkmarks for pasting into a report or chat. Copy Diff for This File puts one file's change on the clipboard as a valid unified diff.
• Inspect mode changes, submodule pointers, and renames without edits as explicit metadata entries rather than temporary notifications.
• Reopening the same source reuses its review instead of accumulating duplicate tabs.
• Use Refresh Review after editing the patch. Saving an open source patch also offers to refresh; it does not silently replace the snapshot you were reviewing.

Refresh keeps the selected repository and base expression. Checkmarks survive only for changes whose contents and metadata are unchanged. Series navigation replaces the review's current Changes tab rather than opening a tab per message. Regenerating the source patch outside the editor offers the same refresh as saving it in the editor; the open snapshot is never silently replaced.

Reviews are also remembered across reloads: reopening an unchanged patch restores its reviewed checkmarks and retries the previously chosen repository and base first, and Reopen Recent Patch... lists recent reviews, including series. The remembered list stays on this machine.

Read-only, bounded operation

Your repository's working tree, index, references, and objects are not modified. Git uses a private index and object database, and object-writing commands cannot access the source alternates. Scratch data is removed on success, failure, cancellation, and limits. Missing objects are not fetched from a remote.

Both sides are then served as read-only, in-memory documents. There is no arbitrary twenty-review eviction: content remains available while its Changes tab or individual file diff is open. Closing the last owned tab releases the extension's buffers.

Binary and undecodable files show their sizes and content fingerprints, so equal-size binary changes cannot look identical merely because their lengths match. Text with recognized byte-order marks is decoded explicitly.

Loading progress has a Cancel button. Default limits use mebibytes (MiB), where one MiB is 1,048,576 bytes:

Limits fail explicitly; they do not truncate content or evict another open review. Close reviews or adjust the appropriate setting before retrying. The retained-content limit counts file buffers, not VS Code's own text models or all JavaScript object overhead. The output limit includes both standard output and standard error.

Set these options in user or remote settings, not workspace settings. viewPatch.repositories defaults to []; a leading ~ in an extra repository path means your home folder.

Requirements and limits

• VS Code 1.90 or newer.
• Git on PATH, or configured through git.path, for complete-file reviews.
• Workspace trust for Git-backed reviews. Hunk-only views work in Restricted Mode.
• In a remote window, the extension and Git-backed operations run next to the remote repositories.
• In VS Code for the Web and virtual workspaces, hunk-only reviews work; Git-backed reviews need a desktop window with a local repository. Web support is new in this release and still being exercised.
• Git and standard unified diffs are supported, including combined merge diffs as described above. Malformed or truncated hunks are rejected explicitly. quoted-printable and base64 mail bodies are decoded; other encodings and multipart mail are rejected with the reason named.

Privacy and troubleshooting

View Patch does not collect telemetry, contact a hosting service, or fetch missing objects. The View Patch output channel (View > Output) explains repository selection, cancellation, limits, and Git failures. For a bug report, View Patch: Copy Diagnostics puts the version, editor, platform, and Git details on the clipboard, and Open Sample Patch checks an install without touching any repository.

Common first-run errors

License

MIT