diff

• Type: string
• CLI: --diff=<path>

DiffOptions object or a path to a module which exports DiffOptions. Useful if you want to customize diff display.

For example, as a config object:

import { defineConfig } from 'vitest/config'
import c from 'picocolors'

export default defineConfig({
  test: {
    diff: {
      aIndicator: c.bold('--'),
      bIndicator: c.bold('++'),
      omitAnnotationLines: true,
    },
  },
})

Or as a module:

vitest.config.js

import { defineConfig } from 'vitest/config'

export default defineConfig({
  test: {
    diff: './vitest.diff.ts',
  },
})

vitest.diff.ts

import type { DiffOptions } from 'vitest'
import c from 'picocolors'

export default {
  aIndicator: c.bold('--'),
  bIndicator: c.bold('++'),
  omitAnnotationLines: true,
} satisfies DiffOptions

diff.expand

• Type: boolean
• Default: true
• CLI: --diff.expand=false

Expand all common lines.

diff.truncateThreshold

• Type: number
• Default: 0
• CLI: --diff.truncateThreshold=<path>

The maximum length of diff result to be displayed. Diffs above this threshold will be truncated. Truncation won't take effect with default value 0.

diff.truncateAnnotation

• Type: string
• Default: '... Diff result is truncated'
• CLI: --diff.truncateAnnotation=<annotation>

Annotation that is output at the end of diff result if it's truncated.

diff.truncateAnnotationColor

• Type: DiffOptionsColor = (arg: string) => string
• Default: noColor = (string: string): string => string

Color of truncate annotation, default is output with no color.

diff.printBasicPrototype

• Type: boolean
• Default: false

Print basic prototype Object and Array in diff output

diff.maxDepth

• Type: number
• Default: 20 (or 8 when comparing different types)

Limit the depth to recurse when printing nested objects