fix: handle consecutive added empty file diff

[yeonjuan]

fixes #31

[Copilot]

Pull Request Overview

This PR fixes handling of consecutive empty-file diffs and refines parsing logic to correctly classify file changes.

• Update comparison-line parsing to streamline to/from extraction
• Change extended-header handling to skip comparison lines without consuming them
• Add fixtures, tests, and snapshots for empty-file and no-prefix scenarios; update existing snapshots

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/parse-git-diff.ts	Adjust token parsing in parseComparisonInputLine and header flow in parseExtendedHeader
src/tests/consecutive-empty-files.test.ts	Add test for parsing consecutive empty-file diffs
src/tests/snapshots/consecutive-empty-files.test.ts.snap	New snapshot for empty-file test
src/tests/snapshots/31.test.ts.snap	Update snapshot to reflect new file type classification
src/tests/31.test.ts	Remove .only from existing test suite
src/tests/31-no-prefix.test.ts	Add test for noPrefix option
src/fixtures/consecutive-empty-files	Add fixture representing multiple empty-file diffs
src/fixtures/31-no-prefix	Add fixture for no-prefix diff scenario

Comments suppressed due to low confidence (1)

src/parse-git-diff.ts:138

• Destructuring the reversed split tokens can misassign 'to' and 'from' if the diff line contains extra segments. Consider filtering parts by 'b/' and 'a/' prefixes (e.g., using find) to ensure correct file path extraction.

const [to, from] = line.split(' ').reverse();

[Copilot]

Returning null without consuming the comparison line may leave the parser cursor on the same line and disrupt subsequent parsing. Consider calling ctx.nextLine() before returning to advance properly.

Suggested change

	if (isComparisonInputLine(ctx.getCurLine())) {
	if (isComparisonInputLine(ctx.getCurLine())) {
	ctx.nextLine();