^get-tsconfig

Find and parse tsconfig.json files.

Features

• Zero dependency (not even TypeScript)
• Tested against TypeScript for correctness
• Supports comments & dangling commas in tsconfig.json
• Resolves extends
• Fully typed tsconfig.json
• Validates and throws parsing errors
• Tiny! 7 kB Minified + Gzipped

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Install

1npm install get-tsconfig

Why?

For TypeScript related tooling to correctly parse tsconfig.json file without depending on TypeScript.

API

getTsconfig(searchPath?, configName?, cache?)

Searches for a tsconfig file (defaults to tsconfig.json) in the searchPath and parses it. (If you already know the tsconfig path, use parseTsconfig instead). Returns null if a config file cannot be found, or an object containing the path and parsed TSConfig object if found.

Returns:

1type TsconfigResult = {
2
3    /**
4     * The path to the tsconfig.json file
5     */
6    path: string
7
8    /**
9     * The resolved tsconfig.json file
10     */
11    config: TsConfigJsonResolved
12}

searchPath

Type: string

Default: process.cwd()

Accepts a path to a file or directory to search up for a tsconfig.json file.

configName

Type: string

Default: tsconfig.json

The file name of the TypeScript config file.

cache

Type: Map<string, any>

Default: new Map()

Optional cache for fs operations.

Example

1import { getTsconfig } from 'get-tsconfig'
2
3// Searches for tsconfig.json starting in the current directory
4console.log(getTsconfig())
5
6// Find tsconfig.json from a TypeScript file path
7console.log(getTsconfig('./path/to/index.ts'))
8
9// Find tsconfig.json from a directory file path
10console.log(getTsconfig('./path/to/directory'))
11
12// Explicitly pass in tsconfig.json path
13console.log(getTsconfig('./path/to/tsconfig.json'))
14
15// Search for jsconfig.json - https://code.visualstudio.com/docs/languages/jsconfig
16console.log(getTsconfig('.', 'jsconfig.json'))

---

parseTsconfig(tsconfigPath, cache?)

Parse the tsconfig file provided. Used internally by getTsconfig. Returns the parsed tsconfig as TsConfigJsonResolved.

tsconfigPath

Type: string

Required path to the tsconfig file.

cache

Type: Map<string, any>

Default: new Map()

Optional cache for fs operations.

Example

1import { parseTsconfig } from 'get-tsconfig'
2
3// Must pass in a path to an existing tsconfig.json file
4console.log(parseTsconfig('./path/to/tsconfig.custom.json'))

---

createFileMatcher(tsconfig: TsconfigResult, caseSensitivePaths?: boolean)

Given a tsconfig.json file, it returns a file-matcher function that determines whether it should apply to a file path.

1type FileMatcher = (filePath: string) => TsconfigResult['config'] | undefined

tsconfig

Type: TsconfigResult

Pass in the return value from getTsconfig, or a TsconfigResult object.

caseSensitivePaths

Type: boolean

By default, it uses is-fs-case-sensitive to detect whether the file-system is case-sensitive.

Pass in true to make it case-sensitive.

Example

For example, if it's called with a tsconfig.json file that has include/exclude/files defined, the file-matcher will return the config for files that match include/files, and return undefined for files that don't match or match exclude.

1const tsconfig = getTsconfig()
2const fileMatcher = tsconfig && createFileMatcher(tsconfig)
3
4/*
5 * Returns tsconfig.json if it matches the file,
6 * undefined if not
7 */
8const configForFile = fileMatcher?.('/path/to/file.ts')
9const distCode = compileTypescript({
10    code: sourceCode,
11    tsconfig: configForFile
12})

---

createPathsMatcher(tsconfig: TsconfigResult)

Given a tsconfig with compilerOptions.paths defined, it returns a matcher function.

The matcher function accepts an import specifier (the path to resolve), checks it against compilerOptions.paths, and returns an array of possible paths to check:

1function pathsMatcher(specifier: string): string[]

This function only returns possible paths and doesn't actually do any resolution. This helps increase compatibility wtih file/build systems which usually have their own resolvers.

Example

1import { getTsconfig, createPathsMatcher } from 'get-tsconfig'
2
3const tsconfig = getTsconfig()
4const pathsMatcher = createPathsMatcher(tsconfig)
5
6const exampleResolver = (request: string) => {
7    if (pathsMatcher) {
8        const tryPaths = pathsMatcher(request)
9
10        // Check if paths in `tryPaths` exist
11    }
12}

FAQ

How can I use TypeScript to parse tsconfig.json?

This package is a re-implementation of TypeScript's tsconfig.json parser.

However, if you already have TypeScript as a dependency, you can simply use it's API:

1import {
2    sys as tsSys,
3    findConfigFile,
4    readConfigFile,
5    parseJsonConfigFileContent
6} from 'typescript'
7
8// Find tsconfig.json file
9const tsconfigPath = findConfigFile(process.cwd(), tsSys.fileExists, 'tsconfig.json')
10
11// Read tsconfig.json file
12const tsconfigFile = readConfigFile(tsconfigPath, tsSys.readFile)
13
14// Resolve extends
15const parsedTsconfig = parseJsonConfigFileContent(
16    tsconfigFile.config,
17    tsSys,
18    path.dirname(tsconfigPath)
19)

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