a collection of lightweight TypeScript packages for AT Protocol, the protocol powering Bluesky
atproto
bluesky
typescript
npm
feat(lexicons): jit validation
+114
-2
+11
.changeset/spotty-foxes-write.md
+11
.changeset/spotty-foxes-write.md
···
1
+
---
2
+
'@atcute/lexicons': minor
3
+
---
4
+
5
+
JIT-compiled object validation
6
+
7
+
this doesn't eek out as much performance as I hoped, but the added code was small enough that it
8
+
seemed okay to add.
9
+
10
+
this optimization requires the runtime environment to allow the use of `eval()`/`new Function()`,
11
+
and generates an unrolled validation loop.
+3
-1
packages/lexicons/lexicons/lib/validations/index.test.ts
+3
-1
packages/lexicons/lexicons/lib/validations/index.test.ts
···
16
16
array: v.array(v.string()),
17
17
boolean: v.boolean(),
18
18
integer: v.integer(),
19
+
integerWithDefault: v.optional(v.integer(), 42),
20
+
integerWithDefaultFn: v.optional(v.integer(), () => 421),
19
21
string: v.string(),
20
22
});
21
23
···
69
71
v.parse(recordSchema, res);
70
72
});
71
73
72
-
it.only('sets optional defaults', () => {
74
+
it('sets optional defaults', () => {
73
75
const objectSchema = v.object({
74
76
foo: v.optional(v.integer(), 123),
75
77
});
+86
-1
packages/lexicons/lexicons/lib/validations/index.ts
+86
-1
packages/lexicons/lexicons/lib/validations/index.ts
···
7
7
8
8
import { assert } from '../utils.js';
9
9
10
-
import { getGraphemeLength, getUtf8Length, isArray, isObject, lazy, lazyProperty } from './utils.js';
10
+
import {
11
+
allowsEval,
12
+
getGraphemeLength,
13
+
getUtf8Length,
14
+
isArray,
15
+
isObject,
16
+
lazy,
17
+
lazyProperty,
18
+
} from './utils.js';
11
19
12
20
type Identity<T> = T;
13
21
type Flatten<T> = Identity<{ [K in keyof T]: T[K] }>;
···
1314
1322
get '~run'() {
1315
1323
const shape = resolvedEntries.value;
1316
1324
const len = shape.length;
1325
+
1326
+
const generateFastpass = (): Matcher => {
1327
+
const fields: [string, any][] = [
1328
+
['$joinIssues', joinIssues],
1329
+
['$prependPath', prependPath],
1330
+
];
1331
+
1332
+
let doc = `let $iss,$out;`;
1333
+
1334
+
for (let idx = 0; idx < len; idx++) {
1335
+
const entry = shape[idx];
1336
+
1337
+
const key = entry.key;
1338
+
const esckey = JSON.stringify(key);
1339
+
1340
+
const id = `_${idx}`;
1341
+
1342
+
doc += `{const $val=$in[${esckey}];`;
1343
+
1344
+
if (entry.optional) {
1345
+
doc += `if($val!==undefined){`;
1346
+
} else {
1347
+
doc += `if($val!==undefined||${esckey} in $in){`;
1348
+
}
1349
+
1350
+
doc += `const $res=${id}$schema["~run"]($val,$flags);if($res!==undefined)if($res.ok)${key !== '__proto__' ? `($out??={...$in})[${esckey}]=$res.value` : `Object.defineProperty($out??={...$in},${esckey},{value:$res.value})`};else if((($iss=$joinIssues($iss,$prependPath(${esckey},$res))),$flags&FLAG_ABORT_EARLY))return $iss;}`;
1351
+
1352
+
if (entry.optional) {
1353
+
const schema = entry.schema as OptionalSchema;
1354
+
const innerSchema = schema.wrapped;
1355
+
const defaultValue = schema.default;
1356
+
1357
+
fields.push([`${id}$schema`, innerSchema]);
1358
+
1359
+
if (defaultValue !== undefined) {
1360
+
const calls = typeof defaultValue === 'function' ? `${id}$default()` : `${id}$default`;
1361
+
1362
+
fields.push([`${id}$default`, defaultValue]);
1363
+
1364
+
doc +=
1365
+
key !== '__proto__'
1366
+
? `else($out??={...$in})[${esckey}]=${calls};`
1367
+
: `else Object.defineProperty($out??={...$in},${esckey},{value:${calls}});`;
1368
+
}
1369
+
} else {
1370
+
fields.push([`${id}$schema`, entry.schema]);
1371
+
fields.push([`${id}$missing`, entry.missing]);
1372
+
1373
+
doc += `else if((($iss=$joinIssues($iss,${id}$missing)),$flags&${FLAG_ABORT_EARLY}))return $iss;`;
1374
+
}
1375
+
1376
+
doc += `}`;
1377
+
}
1378
+
1379
+
doc += `if($iss!==undefined)return $iss;if($out!==undefined)return{ok:true,value:$out};`;
1380
+
1381
+
const fn = new Function(
1382
+
`[${fields.map(([id]) => id).join(',')}]`,
1383
+
`return function matcher($in,$flags){${doc}}`,
1384
+
);
1385
+
1386
+
return fn(fields.map(([, field]) => field));
1387
+
};
1388
+
1389
+
if (allowsEval.value) {
1390
+
const fastpass = generateFastpass();
1391
+
1392
+
const matcher: Matcher = (input, flags) => {
1393
+
if (!isObject(input)) {
1394
+
return ISSUE_TYPE_OBJECT;
1395
+
}
1396
+
1397
+
return fastpass(input, flags);
1398
+
};
1399
+
1400
+
return lazyProperty(this, '~run', matcher);
1401
+
}
1317
1402
1318
1403
const matcher: Matcher = (input, flags) => {
1319
1404
if (!isObject(input)) {
+14
packages/lexicons/lexicons/lib/validations/utils.ts
+14
packages/lexicons/lexicons/lib/validations/utils.ts
···
92
92
export const isObject = (input: unknown): input is Record<string, unknown> => {
93
93
return typeof input === 'object' && input !== null && !isArray(input);
94
94
};
95
+
96
+
export const allowsEval = /*#__PURE__*/ lazy((): boolean => {
97
+
if (typeof navigator !== 'undefined' && navigator?.userAgent?.includes('Cloudflare')) {
98
+
return false;
99
+
}
100
+
101
+
try {
102
+
const F = Function;
103
+
new F('');
104
+
return true;
105
+
} catch (_) {
106
+
return false;
107
+
}
108
+
});