feat: add toggleable raw diff view with color support by rm-hull · Pull Request #112 · rm-hull/git-commit-summary

rm-hull · 2026-05-24T22:21:26Z

Add Raw Diff view to TUI. Allow users to inspect staged changes with original git colors before/during commit summary generation.

Key Changes

Git Client: Implemented DiffWithColor using a PTY (pseudo-terminal) to trick git into emitting ANSI color codes.
UI Model:
- Added showDiffView state.
- Implemented CTRL+D toggle between commit view and diff view.
- Added diffColorMsg to handle asynchronous diff loading.
Diff View: Created diffViewModel using bubbles/viewport for scrollable, colored diff output.

User Flow

graph TD
    A[Commit View] -- "CTRL+D" --> B{Diff Loaded?}
    B -- No --> C[Fetch Colored Diff]
    C --> D[Diff View]
    B -- Yes --> D
    D -- "CTRL+D / ESC" --> A

Technical Implementation Detail

git diff normally strips colors when output is piped. To preserve them, the app now spawns git inside a PTY, forcing git to believe it's talking to a real terminal, thus preserving ANSI color codes for the TUI.

Migrated the diff view logic from the main model into a dedicated `diffViewModel` struct to improve separation of concerns and maintainability of the Bubble Tea model. - Introduced `showDiffView` state. - Encapsulated UI rendering and message handling for the diff view. - Simplified the main `Model` update and view logic by delegating to the new component.

Apply strikethrough to the CTRL+K keybinding in the help text to visually indicate the action is currently unavailable or disabled.

github-actions · 2026-05-24T22:21:59Z

	Tests	Passed ✅	Skipped	Failed
JUnit Test Report	56 ran	56 passed	0 skipped	0 failed

Test	Result
JUnit Test Report
com/rm-hull/git-commit-summary/internal/config.TestLoad/Defaults	✅ passed
com/rm-hull/git-commit-summary/internal/config.TestLoad/WithEnvironmentVariables	✅ passed
com/rm-hull/git-commit-summary/internal/config.TestLoad	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/handle_empty_quoted_strings	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/empty_file,_add_new_properties	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/existing_file,_update_properties	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/doesnt_overwrite_values_if_new_value_is_the_same	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/existing_file,_add_new_and_update_existing	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/preserve_comments_and_other_lines	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/handle_mixed_quoting_styles	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/empty_props,_no_changes	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties/properties_with_special_characters	✅ passed
com/rm-hull/git-commit-summary/internal/config.Test_updateProperties	✅ passed
com/rm-hull/git-commit-summary/internal/git.TestClient_prepareCommitMessage/Single_line_message_with_skipCI	✅ passed
com/rm-hull/git-commit-summary/internal/git.TestClient_prepareCommitMessage/Multi-line_message_with_skipCI	✅ passed
com/rm-hull/git-commit-summary/internal/git.TestClient_prepareCommitMessage/Single_line_message_without_skipCI	✅ passed
com/rm-hull/git-commit-summary/internal/git.TestClient_prepareCommitMessage/Multi-line_message_without_skipCI	✅ passed
com/rm-hull/git-commit-summary/internal/git.TestClient_prepareCommitMessage/Empty_message_with_skipCI	✅ passed
com/rm-hull/git-commit-summary/internal/git.TestClient_prepareCommitMessage	✅ passed
com/rm-hull/git-commit-summary/internal/llm_provider.TestNewProvider/GoogleProvider	✅ passed
com/rm-hull/git-commit-summary/internal/llm_provider.TestNewProvider/OpenAIProvider	✅ passed
com/rm-hull/git-commit-summary/internal/llm_provider.TestNewProvider/UnknownProvider	✅ passed
com/rm-hull/git-commit-summary/internal/llm_provider.TestNewProvider	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory/NewHistory	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory/Add_and_Value	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory/Undo	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory/Redo	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory/Undo_at_beginning	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory/Redo_at_end	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory/Add_truncates_future_history	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory/Multiple_Undos_and_Redos	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestHistory	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/tea.KeyMsg_-_CtrlC_in_showSpinner_state	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/tea.KeyMsg_-_CtrlC_in_other_states	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/gitCheckMsg_-_empty_(no_staged_changes)	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/gitCheckMsg_-_non-empty_(staged_changes)	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/gitDiffMsg_with_hint	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/llmResultMsg_-_with_user_message	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/llmResultMsg_-_without_user_message	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/commitMsg	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/regenerateMsg_-_initializes_promptView_with_current_hint	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/userResponseMsg_-_updates_m.hint	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/cancelRegenPromptMsg_-_re-enables_help_text	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/errMsg	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/abortMsg	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/spinner.Update_for_showSpinner_state	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/commitView.Update_for_showCommitView_state	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/promptView.Update_for_showRegeneratePrompt_state	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/llmResultMsg_-_YOLO_mode	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update/llmResultMsg_-_YOLO_mode_-_empty_summary	✅ passed
com/rm-hull/git-commit-summary/internal/ui.TestModel_Update	✅ passed
com/rm-hull/git-commit-summary/internal/version.TestCheckLatestReturnsLatestWhenNewer	✅ passed
com/rm-hull/git-commit-summary/internal/version.TestCheckLatestReturnsEmptyWhenUpToDate	✅ passed
com/rm-hull/git-commit-summary/internal/version.TestCheckLatestReturnsEmptyForDevel	✅ passed
com/rm-hull/git-commit-summary/internal/version.TestCheckLatestWithRevSuffix	✅ passed
com/rm-hull/git-commit-summary/internal/version.TestCheckLatestWithRevSuffixAndUpToDate	✅ passed

View JUnit Test Report

coveralls · 2026-05-24T22:23:04Z

Coverage Report for CI Build 26846112045

Coverage decreased (-1.7%) to 32.269%

Details

Coverage decreased (-1.7%) from the base build.
Patch coverage: 105 uncovered changes across 4 files (22 of 127 lines covered, 17.32%).
3 coverage regressions across 2 files.

Uncovered Changes

File	Changed	Covered	%
internal/git/client.go	45	0	0.0%
internal/ui/diff_view.go	45	11	24.44%
internal/ui/model.go	30	10	33.33%
internal/ui/commit_view.go	7	1	14.29%

Coverage Regressions

3 previously-covered lines in 2 files lost coverage.

File	Lines Losing Coverage	Coverage
internal/ui/model.go	2	60.87%
internal/ui/commit_view.go	1	23.79%

Coverage Stats


Relevant Lines:	1221
Covered Lines:	394
Line Coverage:	32.27%
Coverage Strength:	0.35 hits per line

💛 - Coveralls

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

- Consolidate duplicate diff argument construction into `diffArgs` helper - Update `diff_view` UI to mark removed shortcuts as strikethrough

- Update `diffArgs` to accept an exclusion flag for better control. - Enhance error handling in `DiffWithColor` for `io.Copy` and `cmd.Wait`. - Simplify `repeatCount` calculation in `diffViewModel` using `max`.

Cache the `lipgloss.Style` in the `diffViewModel` struct instead of re-instantiating it on every view update to improve rendering efficiency.

- Inline `viewport` initialization in `commitViewModel`. - Update `diffViewModel` help text to include new keybindings: - **CTRL+K**: Clear - **CTRL+P**: Editor (swapped from Preview)

…t/diff-view * 'main' of github.com:rm-hull/git-commit-summary: fix: streamline summary generation with persistent hints (#116) fix: re-enable help text when cancelling regeneration (#115) chore: migrate to Charm v2 ecosystem (#114) chore: update download stats [skip ci] chore: go get -u && go mod tidy (#113)

Consolidate `Diff` and `DiffWithColor` into a single, parameterized `Diff` method to reduce code duplication and simplify the `GitClient` interface. - Updated `GitClient` interface to support color and exclusion flags. - Simplified `Model` diff retrieval by calling the unified `Diff` method. - Cleaned up redundant UI code.

- Replace tabs with spaces in diff output for consistent formatting. - Refactor state transitions to use custom message types for `showDiffView` and `cancelDiffView`. - Clean up `Update` logic in the main model for better maintainability.

Moved `diffColorMsg` from `diff_view.go` to the main `model.go` struct to centralize state management and allow access across different UI components.

Removed `width` and `height` from the `Model` struct as they are no longer being utilized within the UI logic.

rm-hull · 2026-05-25T15:08:05Z

/gemini review

gemini-code-assist

Code Review

This pull request introduces a raw diff view accessible via CTRL+D and integrates PTY support to provide colored git diffs. Key changes include refactoring the GitClient interface, implementing a new diffViewModel, and updating the UI state machine to handle diff transitions. Feedback highlights a potential syscall.EIO error when reading from PTY on Linux, a missing window resize handler for the new view, and the accidental removal of the undo hint from the help text. Additionally, a correction was suggested for the mock git client in tests to properly track arguments.

gemini-code-assist · 2026-05-25T15:10:27Z

+	if _, err := io.Copy(&buf, ptmx); err != nil {
+		return "", errors.Wrap(err, "reading git diff output failed")
+	}


On Linux systems, reading from a PTY master file descriptor often returns a syscall.EIO error when the child process (in this case, git) terminates. This will cause io.Copy to return an error even if the command executed successfully and all output was captured. You should check for this specific error and treat it as an EOF if the command otherwise succeeded.

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Update `TestModel_Update` to include the required boolean flags for the `Diff` method call to match the updated internal API signature.

rm-hull added 3 commits May 24, 2026 22:34

wip

1c99f48

style: update commit view help text style

a8030bf

Apply strikethrough to the CTRL+K keybinding in the help text to visually indicate the action is currently unavailable or disabled.

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rm-hull changed the title ~~Feat/diff view~~ feat: add toggleable raw diff view with color support May 24, 2026

rm-hull and others added 11 commits May 24, 2026 23:35

Update internal/git/client.go

b0d0f44

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

refactor: extract git diff argument builder

6fa85f5

- Consolidate duplicate diff argument construction into `diffArgs` helper - Update `diff_view` UI to mark removed shortcuts as strikethrough

refactor: improve git diff logic and UI cleanup

2a1a94e

- Update `diffArgs` to accept an exclusion flag for better control. - Enhance error handling in `DiffWithColor` for `io.Copy` and `cmd.Wait`. - Simplify `repeatCount` calculation in `diffViewModel` using `max`.

refactor: move boxStyle to diffViewModel struct

b2607cf

Cache the `lipgloss.Style` in the `diffViewModel` struct instead of re-instantiating it on every view update to improve rendering efficiency.

refactor: streamline view initialization and update UI keys

ec54b4a

- Inline `viewport` initialization in `commitViewModel`. - Update `diffViewModel` help text to include new keybindings: - **CTRL+K**: Clear - **CTRL+P**: Editor (swapped from Preview)

feat: improve diff display and navigation

e4bcbde

- Replace tabs with spaces in diff output for consistent formatting. - Refactor state transitions to use custom message types for `showDiffView` and `cancelDiffView`. - Clean up `Update` logic in the main model for better maintainability.

refactor: remove manual window resizing logic

44bc5e5

refactor: move diffColorMsg to shared model

0c4a405

Moved `diffColorMsg` from `diff_view.go` to the main `model.go` struct to centralize state management and allow access across different UI components.

refactor: remove unused dimension fields from Model

99410d7

Removed `width` and `height` from the `Model` struct as they are no longer being utilized within the UI logic.

gemini-code-assist Bot reviewed May 25, 2026

View reviewed changes

Update internal/ui/model_test.go

4a64529

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

rm-hull marked this pull request as draft May 25, 2026 20:17

rm-hull added 2 commits May 26, 2026 08:54

test: update git diff mock parameters

e8b84e3

Update `TestModel_Update` to include the required boolean flags for the `Diff` method call to match the updated internal API signature.

Merge branch 'main' into feat/diff-view

fe8f1f4

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feat: add toggleable raw diff view with color support#112

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Key Changes

User Flow

Technical Implementation Detail

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Coverage Report for CI Build 26846112045

Coverage decreased (-1.7%) to 32.269%

Details

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Coverage Stats

💛 - Coveralls

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rm-hull commented May 24, 2026 •

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