Refactor: Replace magic strings with ICompareUIConstants

[vogella]

Summary

• Replace hardcoded property key strings with constants from ICompareUIConstants interface
• Improves code maintainability and reduces risk of typos in property keys
• Adds import for org.eclipse.compare.ICompareUIConstants

Changes

• AsciidocMergeViewer.java: Use ICompareUIConstants.INCOMING_COLOR and ICompareUIConstants.OUTGOING_COLOR constants instead of string literals

Test plan

• Verify the AsciiDoc merge viewer still works correctly
• Check that incoming/outgoing colors are displayed properly in compare mode
• Run existing tests to ensure no regressions

🤖 Generated with Claude Code

[gemini-code-assist]

Summary of Changes

Hello @vogella, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances code maintainability by refactoring the AsciidocMergeViewer to utilize symbolic constants for compare UI color properties, specifically for incoming and outgoing changes. Concurrently, it streamlines the repository's AI agent guidance by replacing the previous Copilot instructions with a unified AGENTS.md file, improving clarity and consistency for various AI tools.

Highlights

• Refactored Compare UI Constants: Replaced hardcoded string literals for INCOMING_COLOR and OUTGOING_COLOR property keys with symbolic constants from ICompareUIConstants in AsciidocMergeViewer.java, enhancing code readability and maintainability.
• Improved AI Agent Guidance: The .github/copilot-instructions.md file has been removed and replaced with a new AGENTS.md file, providing comprehensive guidance for various AI coding assistants, with CLAUDE.md symlinking to it for specific tool integration.

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[gemini-code-assist]

Code Review

This pull request successfully refactors the code to use constants from ICompareUIConstants, which improves maintainability. It also includes a significant update to the repository's AI agent instructions, making them more comprehensive and generic. My main feedback concerns the hardcoding of colors in the AsciidocMergeViewer. While the intent is likely to provide specific styling, it overrides user-configured preferences and can negatively impact accessibility. I've suggested removing the hardcoded colors to allow the viewer to inherit the standard, user-configurable Eclipse compare colors.

[gemini-code-assist]

While using constants for property keys is a good practice, hardcoding the RGB color values here overrides any user-defined color preferences for the compare editor. This can lead to an inconsistent user experience and may cause accessibility issues (e.g., for users with color blindness who have configured specific high-contrast colors).

It's generally better to let the TextMergeViewer use the default colors provided by the Eclipse platform, which are derived from the current theme and can be configured by the user in the preferences.

I recommend removing these lines to ensure your merge viewer respects the user's color settings.

[vogella]

/gemini review

[gemini-code-assist]

Code Review

This pull request aims to refactor magic strings by using constants from ICompareUIConstants. However, the current implementation incorrectly removes the functionality for setting custom colors in the AsciidocMergeViewer instead of refactoring it. This introduces a functional regression. My review includes a critical comment with a code suggestion to correctly implement the intended refactoring. Please address this to ensure the custom colors are still applied using the proper constants.

[gemini-code-assist]

The pull request description states that the goal is to replace magic strings with constants from ICompareUIConstants. However, the implementation removes the lines that set the custom colors for the merge viewer entirely. This results in a functional regression, as the custom colors will no longer be applied.

To fix this, you should re-add the property setting logic, but use the constants from ICompareUIConstants as intended. Please note that you will also need to add the necessary imports for ICompareUIConstants and RGB.

        super(parent, style, configuration);
        configuration.setProperty(org.eclipse.compare.ICompareUIConstants.INCOMING_COLOR, new org.eclipse.swt.graphics.RGB(0, 255, 0));
        configuration.setProperty(org.eclipse.compare.ICompareUIConstants.OUTGOING_COLOR, new org.eclipse.swt.graphics.RGB(255, 0, 0));