import * as fs from 'fs/promises';
import * as diff from 'diff';
export interface DiffResult {
additions: number;
deletions: number;
changes: number;
content: string;
}
export class DiffService {
async compareFiles(
file1: string,
file2: string,
options?: {
format?: 'unified' | 'side-by-side' | 'inline';
context?: number;
ignoreWhitespace?: boolean;
}
): Promise<DiffResult> {
try {
const content1 = await fs.readFile(file1, 'utf-8');
const content2 = await fs.readFile(file2, 'utf-8');
let diffResult;
if (options?.ignoreWhitespace) {
diffResult = diff.createPatch(
file1,
content1.replace(/\s+/g, ' '),
content2.replace(/\s+/g, ' '),
'',
'',
{ context: options.context || 3 }
);
} else {
diffResult = diff.createPatch(
file1,
content1,
content2,
'',
'',
{ context: options?.context || 3 }
);
}
const changes = diff.diffLines(content1, content2);
let additions = 0;
let deletions = 0;
changes.forEach(change => {
if (change.added) {
additions += change.count || 1;
} else if (change.removed) {
deletions += change.count || 1;
}
});
return {
additions,
deletions,
changes: additions + deletions,
content: diffResult
};
} catch (error) {
throw new Error(`Failed to compare files: ${error instanceof Error ? error.message : String(error)}`);
}
}
}
