Matchers

Overview

vitest-snap extends Vitest's expect with four snapshot matchers. Each matcher serializes the received value to a file and diffs it on subsequent runs using Vitest's built-in toMatchFileSnapshot.

Common behaviour

All three matchers:

• Auto-name snapshot files from the current test name (slugified to lowercase).
• Accept an optional options object to override the output directory, filename, and more.
• Are async — always await the call.

await expect(value).toJsonSnapshot();

File path resolution

Snapshot files are written relative to the test file:

<dir>/<slugified-test-name>[_arg1_arg2...]?[.ext]

• dir defaults to ./snapshots.
• args appends extra segments to distinguish parametric snapshots.
• fileExtension is appended as-is (leading dot is optional).

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