4d22232ec0
computeHunks() returns Hunk[] (add | del | ctx) with line numbers on the new side for add/ctx and the old side for del. Both inputs are normalized to end with a newline before calling jsdiff's diffLines, otherwise a missing EOF newline is treated as a token boundary and the last line shows up as a spurious del+add pair.
39 lines
1.1 KiB
TypeScript
39 lines
1.1 KiB
TypeScript
import { diffLines } from 'diff';
|
|
import { Hunk } from './types.js';
|
|
|
|
export function computeHunks(oldText: string, newText: string): Hunk[] {
|
|
// jsdiff treats trailing-newline presence as a token boundary, so a missing
|
|
// EOF newline shows up as a spurious del+add pair on the last line. Normalize.
|
|
const a = oldText.endsWith('\n') ? oldText : oldText + '\n';
|
|
const b = newText.endsWith('\n') ? newText : newText + '\n';
|
|
const parts = diffLines(a, b);
|
|
const out: Hunk[] = [];
|
|
let oldLine = 1;
|
|
let newLine = 1;
|
|
|
|
for (const part of parts) {
|
|
const lines = part.value.split('\n');
|
|
if (lines.length > 0 && lines[lines.length - 1] === '') {
|
|
lines.pop();
|
|
}
|
|
if (part.added) {
|
|
for (const text of lines) {
|
|
out.push({ kind: 'add', lineNo: newLine, text });
|
|
newLine++;
|
|
}
|
|
} else if (part.removed) {
|
|
for (const text of lines) {
|
|
out.push({ kind: 'del', lineNo: oldLine, text });
|
|
oldLine++;
|
|
}
|
|
} else {
|
|
for (const text of lines) {
|
|
out.push({ kind: 'ctx', lineNo: newLine, text });
|
|
oldLine++;
|
|
newLine++;
|
|
}
|
|
}
|
|
}
|
|
|
|
return out;
|
|
}
|