gavel

library0.2.1jsnpmunverified

Gavel is a JavaScript library designed for validating actual HTTP messages against expected HTTP messages. It provides a detailed comparison, indicating discrepancies in status codes, headers, and body content. The library supports JSON Schema validation (Draft 4, 6, and 7) for defining complex body expectations. The current stable version is 10.0.4, last released in December 2021. Its release cadence appears infrequent, with recent updates primarily focused on security patches for internal dependencies rather than new feature development. Gavel differentiates itself by offering granular validation results, pinpointing exact failures, including specific error messages and locations within JSON Schema mismatches, making it a valuable tool for API contract testing and robust HTTP interaction validation.

testing http-networking serialization

npm install gavel

github ↗package ↗

INSTALL

IMPORT

SIG · GAVEL

gavel

testingjavascriptv0.2.1

Install

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Import

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Disk

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Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

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

gavel

✓ import gavel from 'gavel';

✗ const gavel = require('gavel');

While the README shows CJS, for modern TypeScript/ESM projects, use `import gavel from 'gavel';`. Gavel ships with TypeScript types.

gavel.validate

✓ import gavel from 'gavel'; const result = gavel.validate(expected, actual);

✗ import { validate } from 'gavel'; // Gavel does not expose named exports for core functions directly.

The primary validation logic is exposed as a method on the default `gavel` object.

Gavel.ValidationResult

✓ import type { GavelValidationResult } from 'gavel';

For type-checking the validation result object, import `GavelValidationResult`.

Demonstrates basic HTTP transaction validation, including status code, headers, and JSON body against a schema.

import gavel from 'gavel'; const expected = { statusCode: 200, headers: { 'Content-Type': 'application/json' }, bodySchema: { type: 'object', properties: { message: { type: 'string' } }, required: ['message'] } }; const actual = { statusCode: 200, headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ message: 'Hello, world!' }) }; const result = gavel.validate(expected, actual); console.log(result);

Debug

Known issues

breakingGavel v10.0.0 increased the minimum required Node.js version to `v10.18`.

fix

Ensure your Node.js environment is at least v10.18.0. Update Node.js if necessary.

affects: >=10.0.0

gotchaThe Gavel CLI is explicitly stated as not supported on Windows environments.

fix

For Windows users, use the Node.js API directly or a WSL (Windows Subsystem for Linux) environment for CLI usage.

affects: >=1.0.0

gotchaRecent releases (v10.0.x) primarily consist of dependency security updates (e.g., `glob-parent`, `tar`, `lodash`). While fixes, frequent updates for transitive dependencies might indicate an older dependency tree or potential supply chain risks if not regularly patched.

fix

Regularly update `gavel` to the latest patch version to incorporate critical security fixes. Perform routine dependency audits.

affects: >=10.0.0

Errors

Common errors & fixes

ReferenceError: require is not defined in ES module scope

Attempting to use CommonJS `require()` in an ESM context (e.g., in a `.mjs` file or when `type: "module"` is set in `package.json`).

fix

Use ESM `import gavel from 'gavel';` instead of `const gavel = require('gavel');`.

Expected status code '200', but got '404'.

The actual HTTP response status code does not match the expected status code defined in the validation rules.

fix

Adjust the `expected.statusCode` value to match the anticipated actual status code, or verify that the actual response is indeed incorrect.

At '/fruits/2' Invalid type: number (expected string)

The actual HTTP body data does not conform to the JSON Schema provided in `expected.bodySchema` at the specified JSON Pointer path.

fix

Modify the `actual.body` to match the expected JSON Schema structure and data types, or refine the `expected.bodySchema` to accurately reflect valid inputs.

Upgrade

Version history

0.2.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/apiaryio/gavel.js ↗

packagehttps://www.npmjs.com/package/gavel ↗