String Diff Utilities

function computeTextDiff(originalText: string, modifiedText: string): DiffResult

function getCharacterDifferences(original: string, modified: string): CharDiffResult

/** Statistics summarizing the diff results, including counts of added, removed, changed, and unchanged lines. */
interface DiffStats {
	/** Total number of lines that were added in the modified string compared to the original. */
	linesAdded: number;
	/** Total number of lines that were removed from the original string in the modified version. */
	linesRemoved: number;
	/** Total number of lines that were modified (changed content) between the original and modified strings. */
	linesChanged: number;
	/** Total number of lines that remained unchanged between the original and modified strings. */
	linesUnchanged: number;
}

/** The result of a line-level diff operation, including an array of line differences and summary statistics. */
interface DiffResult {
	/** An array of line differences, where each line is categorized as 'added', 'removed', 'unchanged', or 'modified'. */
	lines: DiffLine[];
	/** Statistics summarizing the diff results, including counts of added, removed, changed, and unchanged lines. */
	stats: DiffStats;
}

/** Represents a single line's diff status between two strings, including the type of difference and the content of the line in both original and modified strings. */
type DiffLine = UnchangedOrModifiedDiffLine | AddedDiffLine | RemovedDiffLine;

/** Represents the details of a single line in the diff, including its content and line number. */
interface DiffLineDetails {
	/** The content of the original line, omitted for `added` lines. */
	original: string;
	/** The content of the modified line, omitted for `removed` lines. */
	modified: string;
	/** The line number in the original string (1-based), omitted for `added` lines. */
	originalLineNum: number;
	/** The line number in the modified string (1-based), omitted for `removed` lines. */
	modifiedLineNum: number;
}

/** Represents an unchanged or modified line, including both original and modified content and their respective line numbers. */
interface UnchangedOrModifiedDiffLine extends DiffLineDetails {
	/** The type of difference, either `'unchanged'` or `'modified'`. */
	type: 'unchanged' | 'modified';
}

/** Represents an added line, including only its content and line number in the modified string. */
interface AddedDiffLine extends Omit<DiffLineDetails, 'originalLineNum' | 'original'> {
	/** The type of difference, fixed to `'added'`. */
	type: 'added';
}

/** Represents a removed line, including only its content and line number in the original string. */
interface RemovedDiffLine extends Omit<DiffLineDetails, 'modifiedLineNum' | 'modified'> {
	/** The type of difference, fixed to `'removed'`. */
	type: 'removed';
}

/** A single character annotated with a `highlighted` flag indicating whether it differs from the other string in a diff operation. */
interface HighlightedText {
	/** The text content of the character. */
	text: string;
	/** Whether the character is different from the other string in a diff operation. */
	highlighted: boolean;
}

/** Result of a character-level diff, mapping each character in both strings to a `highlighted` flag. */
interface CharDiffResult {
	/** An array of characters from the original string, each annotated with a `highlighted` flag indicating whether it differs from the modified string. */
	original: HighlightedText[];
	/** An array of characters from the modified string, each annotated with a `highlighted` flag indicating whether it differs from the original string. */
	modified: HighlightedText[];
}