feat(scm): Customizable SCM Graph History Item Formatting (GitLens-style Variable Support)

[Zahariel1942]

Overview

This PR implements customizable formatting for SCM Graph History items in VS Code #255719, allowing users to personalize how commit history is displayed in the Source Control Graph view. Inspired by GitLens, it introduces a configuration option for variable-based formatting, enabling greater flexibility and clarity for teams and individuals.

Key Changes

1. Configuration Setting

Added "scm.graph.historyItemFormat" to src/vs/workbench/contrib/scm/browser/scm.contribution.ts:

• Type: string
• Description: Controls the format of each history item in the Source Control Graph view. Supports variables:
  • ${author} — Commit author name
  • ${authorEmail} — Author email
  • ${subject} — Commit subject/title
  • ${message} — Full commit message
  • ${hash} — Full commit hash
  • ${displayId} — Shortened commit hash
  • ${date} — Relative date (e.g., "2 hours ago")
  • ${timestamp} — Full timestamp

Examples:

• ${subject}
• ${displayId} - ${subject}
• ${author} • ${subject}
• [${displayId}] ${subject} by ${author}
• ${subject} (${date})

2. Formatting Function

Introduced formatHistoryItem in src/vs/workbench/contrib/scm/browser/util.ts:

• Replaces variables in the format string with actual commit data.
• Handles missing values gracefully (empty string fallback).
• Preserves line breaks in commit messages.
• Removes trailing spaces for clean appearance.

3. Renderer Integration

Updated HistoryItemRenderer in src/vs/workbench/contrib/scm/browser/scmHistoryViewPane.ts:

• Observes configuration changes for "scm.graph.historyItemFormat" using VS Code's observable pattern.
• Uses autorun for real-time UI updates when settings change.
• Applies custom formatting via formatHistoryItem.

4. Comprehensive Testing

Added test coverage in src/vs/workbench/contrib/scm/test/browser/util.test.ts:

• Tests all supported variables.
• Validates default and multi-variable formats.
• Checks handling of missing values and edge cases.
• Includes GitLens-style example formats.

[Zahariel1942]

@microsoft-github-policy-service agree

@Zahariel1942 please read the following Contributor License Agreement(CLA). If you agree with the CLA, please reply with the following information.

@microsoft-github-policy-service agree [company="{your company}"]

Options:

• (default - no company specified) I have sole ownership of intellectual property rights to my Submissions and I am not making Submissions in the course of work for my employer.

@microsoft-github-policy-service agree

• (when company given) I am making Submissions in the course of work for my employer (or my employer has intellectual property rights in my Submissions by contract or applicable law). I have permission from my employer to make Submissions and enter into this Agreement on behalf of my employer. By signing below, the defined term “You” includes me and my employer.

@microsoft-github-policy-service agree company="Microsoft"

Contributor License Agreement