Result References

The return value of TwoSlash contains the following information:

TwoSlash Rendered

export interface TwoSlashReturn {
  /** The output code, could be TypeScript, but could also be a JS/JSON/d.ts */
  code: string
  /** Nodes containing various bits of information about the code */
  nodes: TwoSlashNode[]
  /** The meta information the twoslash run */
  meta: TwoSlashReturnMeta
  /** Getters shorthand */
  get queries(): NodeQuery[]
  get completions(): NodeCompletion[]
  get errors(): NodeError[]
  get highlights(): NodeHighlight[]
  get hovers(): NodeHover[]
  get tags(): NodeTag[]
}

Input Code

import type { NodeCompletion, NodeError, NodeHighlight, NodeHover, NodeQuery, NodeTag, TwoSlashNode, TwoSlashReturnMeta } from 'twoslash'
// ---cut---
export interface TwoSlashReturn {
  /** The output code, could be TypeScript, but could also be a JS/JSON/d.ts */
  code: string
  /** Nodes containing various bits of information about the code */
  nodes: TwoSlashNode[]
  /** The meta information the twoslash run */
  meta: TwoSlashReturnMeta
  /** Getters shorthand */
  get queries(): NodeQuery[]
  get completions(): NodeCompletion[]
  get errors(): NodeError[]
  get highlights(): NodeHighlight[]
  get hovers(): NodeHover[]
  get tags(): NodeTag[]
}

Check the type definition for all the fields.

Information Nodes

TwoSlash returns all types of information in the nodes array. Check the type definition for all the fields.

Properties

Nodes provide the following common properties:

• type: the type of the node. Can be hover, query, error, tag, highlight or completion
  • was kind in @typescript/twoslash for some entries
• start: the 0-indexed start position of the node in the output code
• line: a 0-indexed line number of the node in the output code
• character: a 0-indexed character number of the node in the output code
  • was offset in @typescript/twoslash for some entries
• length: length of the node

For different types of nodes, they have some extra properties:

Type hover

• text: the text of the hover, usually the type information of the given node
• docs: the jsdoc of the given node, can be undefined

Type query

Same as hover

Type highlight

• text: the extra annotation text of the highlight, can be undefined

Type completion

• completion: the completion entries
• completionPrefix: the prefix of the completion

Type error

• text: the error message
  • was renderedMessage in @typescript/twoslash
• level: the error level
  • was category in @typescript/twoslash
• code: TypeScript error code
• id: a generated based on the code and position of the error

Type tag

• text: the text of the tag
  • was annotation in @typescript/twoslash

Getters

To make it easier to access, we also provide some getters shortcuts to each type of the nodes:

import type { NodeCompletion, NodeError, NodeHighlight, NodeHover, NodeQuery, NodeTag, TwoSlashNode, TwoSlashReturnMeta } from 'twoslash'
// ---cut---
export interface TwoSlashReturn {
  nodes: TwoSlashNode[]

  get hovers(): NodeHover[] // was `staticQuickInfos`
  get queries(): NodeQuery[] // was `queries` with `kind: 'query'`
  get completions(): NodeCompletion[] // was `queries` with `kind: 'completion'`
  get errors(): NodeError[]
  get highlights(): NodeHighlight[]
  get tags(): NodeTag[]
  // ....
}

Meta Information

An additional meta property is returned providing additional information about the result. Check the type definition for all the fields.

meta.flagNotations

The list of options flag notation that is detected from the code.

meta.removals

A list of the index ranges of the code removed by TwoSlash from the original code, useful for better source mapping.

meta.compilerOptions

The final resolved compilerOptions

meta.handbookOptions

The final resolved handbookOptions