msw-snapshot

library5.3.0jsnpmunverified

Transparently create an API cache for testing using MSW. v5.3.0 (stable). Integrates with MSW v2 to snapshot network requests and replay them in tests, reducing reliance on live APIs. Key differentiators: supports snapshot update strategies (none/all/missing), customizable snapshot paths via createSnapshotPath, and callbacks for fetch events. Ships TypeScript types. Requires msw ^2.0.0 as a peer dependency.

testing

npm install msw-snapshot

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · MSW-SNAPSHOT

msw-snapshot

testingjavascriptv5.3.0

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.

snapshot

✓ import { snapshot } from 'msw-snapshot'

✗ import { snapshot } from 'snapshot'

Do not use bare 'snapshot' import – it's a different package.

context

✓ import { context } from 'msw-snapshot'

Context provides namespace for snapshot isolation per test.

toHashString

✓ import { toHashString } from 'msw-snapshot'

Utility for creating deterministic hash strings, useful in createSnapshotPath.

Sets up an MSW server with snapshot middleware, storing new snapshots on first run and replaying them on subsequent runs.

import { setupServer } from 'msw/node'; import { snapshot, context } from 'msw-snapshot'; const server = setupServer( snapshot({ basePath: './__snapshots__', updateSnapshots: 'missing', onFetchFromServer: (info) => { console.log('Fetched from server:', info.request.url); }, }) ); server.listen(); // Your test code here server.close();

Debug

Known issues

breakingMSW v2 compatibility only – msw-snapshot does not work with MSW v1.

fix

Upgrade to msw ^2.0.0 and use msw-snapshot v5.x.

affects: >=3.0.0 <4.0.0

deprecatedThe 'snapshot' import from 'snapshot' package is deprecated – use 'msw-snapshot'.

fix

Change import to 'import { snapshot } from 'msw-snapshot'.

affects: >=4.0.0

gotchaSnapshot identity relies on createSnapshotPath – naive usage may cause cache misses due to dynamic query params like timestamps.

fix

Use maskURLSearchParams to ignore volatile params, customizing createSnapshotPath accordingly.

affects: *

gotchaUsing updateSnapshots: 'all' can overwrite existing snapshots unintentionally, leading to test flakiness.

fix

Use 'missing' or 'none' for CI; reserve 'all' for local development when intentional.

affects: *

Errors

Common errors & fixes

TypeError: Cannot destructure property 'snapshot' of ... as it is undefined.

Incorrect import path: using 'import { snapshot } from 'snapshot'' instead of 'msw-snapshot'.

fix

Change to: import { snapshot } from 'msw-snapshot'.

Error: MSW v1 is not supported. Please upgrade to MSW v2.

Missing or outdated peer dependency msw (^2.0.0).

fix

Run: npm install msw@^2.0.0

Snapshot not matching – request URL contains a dynamic 't' parameter causing hash mismatch.

createSnapshotPath not configured to mask cache-busting query params.

fix

Use maskURLSearchParams in createSnapshotPath to ignore 't' or other dynamic params.

Upgrade

Version history

5.3.0latest on npm

Audit

Dependencies

mswrequiredRequired peer dependency for mocking service worker functionality.

Agent activity

6 hits · last 30 days

node

Resources

githubhttps://github.com/hrsh7th/msw-snapshot ↗

packagemsw-snapshot ↗

homepagehttps://github.com/hrsh7th/msw-snapshot ↗