Awesome
tsconfig-paths
Use this to load modules whose location is specified in the paths
section of tsconfig.json
or jsconfig.json
. Both loading at run-time and via API are supported.
Typescript by default mimics the Node.js runtime resolution strategy of modules. But it also allows the use of path mapping which allows arbitrary module paths (that doesn't start with "/" or ".") to be specified and mapped to physical paths in the filesystem. The typescript compiler can resolve these paths from tsconfig
so it will compile OK. But if you then try to execute the compiled files with node (or ts-node), it will only look in the node_modules
folders all the way up to the root of the filesystem and thus will not find the modules specified by paths
in tsconfig
.
If you require this package's tsconfig-paths/register
module it will read the paths
from tsconfig.json
or jsconfig.json
and convert node's module loading calls into to physical file paths that node can load.
How to install
yarn add --dev tsconfig-paths
or
npm install --save-dev tsconfig-paths
How to use
With node
node -r tsconfig-paths/register main.js
If process.env.TS_NODE_BASEURL
is set it will override the value of baseUrl
in tsconfig.json:
TS_NODE_BASEURL=./dist node -r tsconfig-paths/register main.js
With ts-node
ts-node -r tsconfig-paths/register main.ts
If process.env.TS_NODE_PROJECT
is set it will be used to resolved tsconfig.json
With webpack
For webpack please use the tsconfig-paths-webpack-plugin.
With mocha and ts-node
As of Mocha >= 4.0.0 the --compiler
was deprecated. Instead --require
should be used. You also have to specify a glob that includes .ts
files because mocha looks after files with .js
extension by default.
mocha -r ts-node/register -r tsconfig-paths/register "test/**/*.ts"
With other commands
As long as the command has something similar to a --require
option that can load a module before it starts, tsconfig-paths should be able to work with it.
With ts-node
and VSCode
The following is an example configuration for the .vscode/launch.json
.
{
"version": "0.2.0",
"configurations": [
{
"name": "Debug Functions",
"request": "launch",
"type": "node",
"runtimeArgs": [
"-r",
"${workspaceFolder}/functions/node_modules/ts-node/register",
"-r",
"${workspaceFolder}/functions/node_modules/tsconfig-paths/register"
],
"args": ["${workspaceFolder}/functions/src/index.ts"],
"cwd": "${workspaceFolder}",
"protocol": "inspector",
"env": {
"NODE_ENV": "development",
"TS_NODE_PROJECT": "${workspaceFolder}/functions/tsconfig.json"
},
"outFiles": ["${workspaceFolder}/functions/lib/**/*.js"]
}
]
}
Bootstrapping with explicit params
If you want more granular control over tsconfig-paths you can bootstrap it. This can be useful if you for instance have compiled with tsc
to another directory where tsconfig.json
doesn't exists.
For example, create a wrapper script called tsconfig-paths-bootstrap.js
with the contents below:
const tsConfig = require("./tsconfig.json");
const tsConfigPaths = require("tsconfig-paths");
const baseUrl = "./"; // Either absolute or relative path. If relative it's resolved to current working directory.
const cleanup = tsConfigPaths.register({
baseUrl,
paths: tsConfig.compilerOptions.paths,
});
// When path registration is no longer needed
cleanup();
Then run with:
node -r ./tsconfig-paths-bootstrap.js main.js
Configuration Options
You can set options by passing them before the script path, via programmatic usage or via environment variables.
ts-node --project customLocation/tsconfig.json -r tsconfig-paths/register "test/**/*.ts"
CLI and Programmatic Options
Environment variable denoted in parentheses.
-P, --project [path]
Path to TypeScript JSON project file (TS_NODE_PROJECT
)
Config loading process
- Use explicit params passed to register
- Use
process.env.TS_NODE_PROJECT
to resolve tsConfig.json and the specified baseUrl and paths. - Resolves tsconfig.json from current working directory and the specified baseUrl and paths.
Programmatic use
The public API consists of these functions:
- register
- loadConfig
- createMatchPath / createMatchPathAsync
- matchFromAbsolutePaths / matchFromAbsolutePathsAsync
register
export interface ExplicitParams {
baseUrl: string;
paths: { [key: string]: Array<string> };
mainFields?: (string | string[])[];
addMatchAll?: boolean;
cwd?: string;
}
/**
* Installs a custom module load function that can adhere to paths in tsconfig.
*/
export function register(explicitParams: ExplicitParams): () => void;
This function will patch the node's module loading so it will look for modules in paths specified by tsconfig.json
or jsconfig.json
.
A function is returned for you to reinstate Node's original module loading.
loadConfig
export function loadConfig(cwd: string = process.cwd()): ConfigLoaderResult;
export type ConfigLoaderResult =
| ConfigLoaderSuccessResult
| ConfigLoaderFailResult;
export interface ConfigLoaderSuccessResult {
resultType: "success";
absoluteBaseUrl: string;
paths: { [key: string]: Array<string> };
}
export interface ConfigLoaderFailResult {
resultType: "failed";
message: string;
}
This function loads the tsconfig.json
or jsconfig.json
. It will start searching from the specified cwd
directory. Passing the tsconfig.json
or jsconfig.json
file directly instead of a directory also works.
createMatchPath
/**
* Function that can match a path
*/
export interface MatchPath {
(
requestedModule: string,
readJson?: Filesystem.ReadJsonSync,
fileExists?: (name: string) => boolean,
extensions?: ReadonlyArray<string>
): string | undefined;
}
/**
* Creates a function that can resolve paths according to tsconfig paths property.
* @param absoluteBaseUrl Absolute version of baseUrl as specified in tsconfig.
* @param paths The paths as specified in tsconfig.
* @param mainFields A list of package.json field names to try when resolving module files. Select a nested field using an array of field names.
* @param addMatchAll Add a match-all "*" rule if none is present
* @returns a function that can resolve paths.
*/
export function createMatchPath(
absoluteBaseUrl: string,
paths: { [key: string]: Array<string> },
mainFields: (string | string[])[] = ["main"],
addMatchAll: boolean = true
): MatchPath {
The createMatchPath
function will create a function that can match paths. It accepts baseUrl
and paths
directly as they are specified in tsconfig and will handle resolving paths to absolute form. The created function has the signature specified by the type MatchPath
above.
matchFromAbsolutePaths
/**
* Finds a path from tsconfig that matches a module load request.
* @param absolutePathMappings The paths to try as specified in tsconfig but resolved to absolute form.
* @param requestedModule The required module name.
* @param readJson Function that can read json from a path (useful for testing).
* @param fileExists Function that checks for existence of a file at a path (useful for testing).
* @param extensions File extensions to probe for (useful for testing).
* @param mainFields A list of package.json field names to try when resolving module files. Select a nested field using an array of field names.
* @returns the found path, or undefined if no path was found.
*/
export function matchFromAbsolutePaths(
absolutePathMappings: ReadonlyArray<MappingEntry.MappingEntry>,
requestedModule: string,
readJson: Filesystem.ReadJsonSync = Filesystem.readJsonFromDiskSync,
fileExists: Filesystem.FileExistsSync = Filesystem.fileExistsSync,
extensions: Array<string> = Object.keys(require.extensions),
mainFields: (string | string[])[] = ["main"]
): string | undefined {
This function is lower level and requires that the paths as already been resolved to absolute form and sorted in correct order into an array.
createMatchPathAsync
This is the async version of createMatchPath
. It has the same signature but with a callback parameter for the result.
matchFromAbsolutePathsAsync
This is the async version of matchFromAbsolutePaths
. It has the same signature but with a callback parameter for the result.
How to publish
yarn version --patch
yarn version --minor
yarn version --major