54 lines
1.6 KiB
TypeScript
54 lines
1.6 KiB
TypeScript
 
|
import { describe, it } from 'node:test';
|
||
|
|
import assert from 'node:assert/strict';
|
||
|
|
import { countChanges, wordDiff, WORD_DIFF_LIMIT } from './wordDiff';
|
||
|
|
|
||
|
|
const render = (tokens: ReturnType<typeof wordDiff>) =>
|
||
|
|
tokens
|
||
|
|
?.map((t) =>
|
||
|
|
t.op === 'same'
|
||
|
|
? t.text
|
||
|
|
: `${t.op === 'add' ? '+' : '-'}[${t.text.trim()}]${t.text.endsWith(' ') ? ' ' : ''}`,
|
||
|
|
)
|
||
|
|
.join('');
|
||
|
|
|
||
|
|
describe('wordDiff', () => {
|
||
|
|
it('returns undefined for identical text', () => {
|
||
|
|
assert.equal(wordDiff('hello world', 'hello world'), undefined);
|
||
|
|
});
|
||
|
|
|
||
|
|
it('marks a replaced word', () => {
|
||
|
|
assert.equal(render(wordDiff('see you at 5', 'see you at 6')), 'see you at -[5]+[6]');
|
||
|
|
});
|
||
|
|
|
||
|
|
it('marks insertions and deletions in place', () => {
|
||
|
|
assert.equal(
|
||
|
|
render(wordDiff('the quick fox', 'the quick brown fox jumps')),
|
||
|
|
'the quick +[brown] fox +[jumps]',
|
||
|
|
);
|
||
|
|
assert.equal(render(wordDiff('a b c d', 'a d')), 'a -[b c] d');
|
||
|
|
});
|
||
|
|
|
||
|
|
it('ignores whitespace-only changes', () => {
|
||
|
|
assert.equal(wordDiff('a b', 'a b'), undefined);
|
||
|
|
assert.equal(wordDiff('a b\n', 'a b'), undefined);
|
||
|
|
});
|
||
|
|
|
||
|
|
it('handles fully different text', () => {
|
||
|
|
assert.deepEqual(wordDiff('one', 'two'), [
|
||
|
|
{ op: 'del', text: 'one' },
|
||
|
|
{ op: 'add', text: 'two' },
|
||
|
|
]);
|
||
|
|
});
|
||
|
|
|
||
|
|
it('gives up past the word limit', () => {
|
||
|
|
const long = Array.from({ length: WORD_DIFF_LIMIT }, (_, i) => `w${i}`).join(' ');
|
||
|
|
assert.equal(wordDiff(long, `${long} extra`), undefined);
|
||
|
|
});
|
||
|
|
|
||
|
|
it('counts changed words', () => {
|
||
|
|
const d = wordDiff('a b c', 'a x y z c');
|
||
|
|
assert.ok(d);
|
||
|
|
assert.deepEqual(countChanges(d), { added: 3, removed: 1 });
|
||
|
|
});
|
||
|
|
});
|