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.

Vitest diff rendering uses @vitest/pretty-format under the hood and a part of DiffOptions is forwarded to the pretty-format configuration, while the rest affects diff rendering itself.

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:

:::code-group

import { defineConfig } from 'vitest/config'

export default defineConfig({
  test: {
    diff: './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.

diff | Config