ow
Version:
Function argument validation for humans
50 lines (49 loc) • 2.01 kB
JavaScript
import callsites from 'callsites';
import { inferLabel } from './utils/infer-label.js';
import { isPredicate } from './predicates/base-predicate.js';
import modifiers from './modifiers.js';
import predicates from './predicates.js';
import test from './test.js';
const ow = (value, labelOrPredicate, predicate) => {
if (!isPredicate(labelOrPredicate) && typeof labelOrPredicate !== 'string') {
throw new TypeError(`Expected second argument to be a predicate or a string, got \`${typeof labelOrPredicate}\``);
}
if (isPredicate(labelOrPredicate)) {
// If the second argument is a predicate, infer the label
const stackFrames = callsites();
test(value, () => inferLabel(stackFrames), labelOrPredicate);
return;
}
test(value, labelOrPredicate, predicate);
};
Object.defineProperties(ow, {
isValid: {
value(value, predicate) {
try {
test(value, '', predicate);
return true;
}
catch {
return false;
}
},
},
create: {
value: (labelOrPredicate, predicate) => (value, label) => {
if (isPredicate(labelOrPredicate)) {
const stackFrames = callsites();
test(value, label ?? (() => inferLabel(stackFrames)), labelOrPredicate);
return;
}
test(value, label ?? (labelOrPredicate), predicate);
},
},
});
// Can't use `export default predicates(modifiers(ow)) as Ow` because the variable needs a type annotation to avoid a compiler error when used:
// Assertions require every name in the call target to be declared with an explicit type annotation.ts(2775)
// See https://github.com/microsoft/TypeScript/issues/36931 for more details.
const _ow = predicates(modifiers(ow));
export default _ow;
export * from './predicates.js';
export { ArgumentError } from './argument-error.js';
export { Predicate } from './predicates/predicate.js';