feat(data-modeling): show previous edits when opening the diagram COMPASS-9544

[mabaasit]

Description

Checklist

• New tests and/or benchmarks are included
• Documentation is changed or added
• If this change updates the UI, screenshots/videos are added and a design review is requested
• I have signed the MongoDB Contributor License Agreement (https://www.mongodb.com/legal/contributor-agreement)

Motivation and Context

• Bugfix
• New feature
• Dependency update
• Misc

Open Questions

Dependents

Types of changes

• Backport Needed
• Patch (non-breaking change which fixes an issue)
• Minor (non-breaking change which adds functionality)
• Major (fix or feature that would cause existing functionality to change)

[Copilot]

Pull Request Overview

This PR implements functionality to preserve edit history when opening existing data modeling diagrams, allowing users to undo previous changes made before the current session. The change ensures that when a diagram is reopened, the undo/redo functionality works with the complete edit history rather than starting fresh.

Key changes:

• Modifies the diagram reducer to preserve edit history when opening saved diagrams
• Adds comprehensive E2E test coverage for the undo functionality after reopening diagrams

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/compass-data-modeling/src/store/diagram.ts	Updates the OPEN_DIAGRAM action to reconstruct the edit history from saved edits
packages/compass-e2e-tests/tests/data-modeling-tab.test.ts	Adds E2E test to verify undo functionality works after reopening a diagram

Comments suppressed due to low confidence (1)

packages/compass-data-modeling/src/store/diagram.ts:98

• The variable name '_item' indicates an unused parameter. Consider using a more descriptive name like 'edit' or simply omit the parameter name since it's not used.

    const prev = current.map((_item, index, arr) => arr.slice(0, index + 1));

[Copilot]

This logic creates an array of progressively longer slices but could be clearer. Consider adding a comment explaining that this reconstructs the edit history states for undo functionality.

Suggested change

	const current = action.diagram.edits;
	const current = action.diagram.edits;
	// Reconstruct the edit history states for undo functionality by creating an array of progressively longer slices of the `current` edits array.