check-compiler

library1.4.0jsnpmunverified

A TypeScript-first schema rule compiler and validation library that compiles declarative rule objects into efficient validation functions. Current stable version is 1.4.0 (released 2023). It has zero dependencies, supports both Node.js (>=16) and browsers, and is very small (minified+gzipped). Unlike runtime validation libraries like zod or yup, check-compiler provides a compiled check function for each schema, making repeated validation fast. It uses a type-driven rule definition with custom messages and supports nested objects, nullable values, and pattern validation. Ships TypeScript types.

testing

npm install check-compiler

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · CHECK-COMPILER

check-compiler

testingjavascriptv1.4.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

compile

✓ import { compile } from 'check-compiler'

Main function to compile a rule object into a check function. ESM only; CommonJS not supported.

Rule

✓ import { Rule } from 'check-compiler'

Type for defining a validation rule. Must be used with generic parameter, e.g., Rule<string>.

Check

✓ import { Check } from 'check-compiler'

Type for the compiled check function signature: (input: T, violations: Violation[]) => void.

Violation

✓ import { Violation } from 'check-compiler'

Interface describing a validation violation: location, message, reason, args.

Creates a string rule with min, max, and pattern, compiles it, and validates two inputs, showing violation details.

import { compile, Rule, Violation } from 'check-compiler'; const nameRule: Rule<string> = { type: 'string', min: 2, max: 50, pattern: /^[a-zA-Z ]+$/, messages: { 'string pattern': 'Only letters and spaces allowed.', }, }; const checkName = compile(nameRule); const violations: Violation[] = []; checkName('John Doe', violations); console.log(violations); // [] checkName('J', violations); // violates min console.log(violations[0].message); // The value must be at least 2 characters.

Debug

Known issues

gotchaNullable fields require explicit nullable: true in the rule; otherwise null values cause violations.

fix

Set nullable: true on the rule object when null is allowed.

affects: >=1.0.0

gotchaCustom messages must use the same key as the built-in reason (e.g., 'string pattern', 'number range'). Incorrect keys are ignored.

fix

Use the exact reason string as the key in the messages object (e.g., 'string pattern' for pattern violations).

affects: >=1.0.0

deprecatedCalling compile() multiple times for the same rule is discouraged; compile once and reuse the check function.

fix

Store compiled check functions and reuse them.

affects: >=1.0.0

gotchaUnknown rule types (e.g., 'boolean', 'date') are not supported and will cause compilation errors.

fix

Use only supported types: 'string', 'number', 'object'. For others, consider custom validation.

affects: >=1.0.0

Errors

Common errors & fixes

Type 'number' has no properties in common with type 'Rule<unknown>'.

Using a plain number/string where a Rule object is expected.

fix

Define a rule object: e.g., { type: 'number', min: 0 } instead of just 0.

Cannot use namespace 'Check' as a type.

Importing Check incorrectly (e.g., `import { Check as CheckType }` instead of `import { Check }`).

fix

Use `import { Check } from 'check-compiler'` directly.

TS2345: Argument of type 'string' is not assignable to parameter of type 'never'.

Passing a value of mismatched type to a compiled check function.

fix

Ensure the input argument matches the generic type used in compile<T>().

Error: Unknown rule type: 'boolean'.

Attempting to use an unsupported rule type like 'boolean' or 'date'.

fix

Switch to a supported type ('string', 'number', 'object') or implement custom validation.

Upgrade

Version history

1.4.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

15 hits · last 30 days

node

Bingbot

OpenAI (training)

Resources

githubhttps://github.com/akornatskyy/check-compiler-js ↗

packagecheck-compiler ↗

homepagehttps://github.com/akornatskyy/check-compiler-js ↗