Fix another bug in diffWords's "intlSegmenter" mode

[ExplodingCabbage]

Fixes#664

[ExplodingCabbage]

Okay, I think this is good to go. Might as well get an AI review, I guess!

[Copilot]

Pull request overview

This PR fixes a crash in diffWords when used with intlSegmenter and text containing combining marks after whitespace characters (issue #664). The root cause was that Intl.Segmenter treats sequences like " \u0300" (space + combining grave accent) as a single non-word segment, causing whitespace deduplication logic to fail.

Changes:

• Added segment() function to merge consecutive whitespace segments from Intl.Segmenter
• Updated leadingWs(), trailingWs(), and added leadingAndTrailingWs() to handle segmenter-based whitespace detection
• Threaded segmenter parameter through whitespace deduplication logic in diffWords

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
test/util/string.js	Added tests for leadingWs and trailingWs with segmenter mode
test/diff/word.js	Added regression tests for combining marks on whitespace; refactored existing test
src/util/string.ts	Implemented segment(), leadingAndTrailingWs(), and updated leadingWs()/trailingWs() to support segmenter
src/diff/word.ts	Updated dedupeWhitespaceInChangeObjects() to pass segmenter parameter through; uses new segment() function
release-notes.md	Documented the fix for version 8.0.4

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[Copilot]

The second argument to wordDiff.tokenize() should be an options object with an intlSegmenter property, not a segmenter directly. This test is passing a segmenter as the second argument directly, which would be assigned to the options parameter but doesn't match the expected structure. The call should be wordDiff.tokenize(string, {intlSegmenter: new Intl.Segmenter({granularity: 'word'})}).

Suggested change

	expect(wordDiff.tokenize(string,newIntl.Segmenter({granularity: 'word'}))).to.deep.equal(expectedResult);
	expect(
	wordDiff.tokenize(string,{
	intlSegmenter: newIntl.Segmenter({granularity: 'word'})
	})
	).to.deep.equal(expectedResult);

[ExplodingCabbage]

Good catch, AI friend!