v0.20.0

Breaking changes

• composeMocks function has been removed (#236, #239). Please use setupWorker instead.

-import { composeMocks, rest } from 'msw'
-composeMocks(rest.get(...))

+import { setupWorker, rest } from 'msw'
+setupWorker(rest.get(...))

Features

• Adds React Native support (#203, #269).

import { setupServer } from 'msw/native'
import { rest } from 'msw'

const server = setupServer(
  rest.get('/user', (req, res, ctx) => {
    return res(ctx.json({ firstName: 'John' })
  })
)

The setupServer API for React Native is the exact mirror of the same API for NodeJS. Read more in the documentation: https://mswjs.io/docs/api/setup-server

• Adds support for binary response types (#221, #224, Binary response type recipe).
• Adds an option to warn/error/execute arbitrary logic on unmatched request (#191, setupWorker docs, setupServer docs).

const server = setupServer(
  rest.get('/books', (req, res, ctx) => res())
)

server.listen({
  onUnhandledRequest: 'error'
})

fetch('/user') // ERROR! Unhandled request.

• Adds a req.cookies property to access a request’s cookies (#199, #261, Accessing request cookies recipe).
• Adds support for network error emulation (#253, res.networkError API):

rest.post('/login', (req, res, ctx) => {
  return res.networkError('Custom error message')
})

Bug fixes

• Fixes an issue that resulted into a "global is not defined" error being thrown in a browser (#255).
• Fixes an issue that resulted into the worker listeners being established multiple times after repetitive calls to worker.start() or Hot Reload (#244).
• Fixes an issue that failed response patching in NodeJS (#264, #266).
• Fixes an issue that resulted into the XMLHttpRequest.prototype.addEventListener events being ignored (#267).
• Fixes an issue that resulted into timeout in POST requests with a body in NodeJS (#277).
• Fixes an invalidly typed req.body in case of GraphQL request (#297, #302).
• Updates library's dependencies (#306).

v0.19.5

Features

• Adds a warning when using redundant query parameters in a request handler URL (#231, #233).
• Throws an exception when running setupWorker in a NodeJS environment (#219).
• Throws an exception when running setupServer in a browser environment (#214, #219).
• Adds a custom error message when calling worker.start() and the worker script doesn’t exist (#237, #242).
• Exports GraphQL type annotations for GraphQLMockedRequest, GraphQLMockedContext, GraphQLRequestPayload, GraphQLResponseResolver types (#213, #241).

Bug fixes

• Sets the default realistic response time of ctx.delay() to 5ms when run in Node environment (including jsdom) (#205).
• Fixes an issue that resulted into the response Promise to never resolve when using jest.useFakeTimers() in your tests (#243).
• Fixes a bug that resulted into a request handler URL with query parameters to produce a false negative match with the identical actual request URL. Query parameters and hashes in a request handler URL no longer affect the matching process.

v0.19.4

Internal

• Updates the repository's homepage and README.

v0.19.3

Bug fixes

• Fixes an issue that resulted into GraphQL requests issued using a GET method not being intercepted (#210, #212).

v0.19.2

Bug fixes

• Fixes an issue that resulted into TypeError [ERR_INVALID_URL]: Invalid URL: undefined//undefined exception when using third-party request issuing libraries in Node (#209, #211).

v0.19.1

Features

• Calling ctx.delay() without any arguments now simulates a random realistic server response time in a range between 100-400ms (#192, #198). Responses in Node are instantaneous.

Bug fixes

• Fixes an issue that resulted into Uncaught (in promise) SyntaxError: Unexpected end of input exception when processing a request. Internally, a request’s body is now always retrieved as text, parsing it as JSON is delegated to the client side (based on the Content-Type header) (#200, #201).

v0.19.0

Features

• The library now defers all the client-side requests that happen between calling worker.start() and successful worker activation. This eliminates race condition between the two, and now comes as the default behavior. (#190, #196)

The behavior of deferring requests can be configured using the waitUntilReady: boolean option on worker.start():

import { setupWorker, rest } from 'msw'

const worker = setupWorker(/* request handlers */)

worker.start({
  // You can opt-out of the deferred network requests behavior.
  waitUntilReady: false
})

v0.18.1

Bug fixes

• Fixes an outdated repository URL in the Service Worker activation message.
• Fixes an issue that resulted into ReferenceError: location is not defined error when using a request handler with a relative URL in setupServer (#193)

v0.18.0

Features

• Adds support for declaring runtime request handlers (#128, #187):
  • .use() to prepend any request handlers. Any prepended request handlers take priority over existing ones, if their predicate match.
    • Usage example of .use() for setupServer
    • Usage example of .use() for setupWorker
  • .restoreHandlers() to mark any used one-time request handlers as unused, allowing them to affect network again.
    • Usage example of .restoreHandlers() for setupServer
    • Usage example of .restoreHandlers() for setupWorker
  • .resetHandlers() to remove any request handlers added on runtime. Optionally accepts a list of next request handlers that replace the initial handlers passed to setupServer/setupWorker call.
    • Usage example of .resetHandlers() for setupServer
    • Usage example of .resetHandlers() for setupWorker
• Adds support for one-time request handlers using res.once(). Such handles will respond with a given mocked response only once upon request match:

rest.get('/books', (req, res, ctx) => {
  return res.once(ctx.json([1, 2, 3]))
})

Bug fixes

• Fixes an issue that resulted into the following TypeScript error when installing msw (#185, #186 ):

TS7016: Could not find a declaration file for module 'cookie'

• Fixes an outdated GitHub repository link in the mockServiceWorker.js file.

v0.17.2

Bug fixes

• Fixes an issue that caused an empty non-JSON request body being parsed as JSON (#175, #179)