# tsc-alias

Replace alias paths with relative paths after typescript compilation. You can add aliases that reference other projects outside your tsconfig.json project by providing a relative path to the baseUrl.

[![npm version](https://badge.fury.io/js/tsc-alias.svg)](https://badge.fury.io/js/tsc-alias)
[![License](https://img.shields.io/:license-mit-blue.svg)](http://doge.mit-license.org)
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## Comparison to [tsconfig-paths](https://github.com/dividab/tsconfig-paths)

\+ Compile time (no runtime dependencies)

## Getting Started

First, install tsc-alias as devDependency using npm.

```sh
npm install -g tsc-alias
```

```sh
npm install --save-dev tsc-alias
```

## Add it to your build scripts in package.json

```json
"scripts": {
  "build": "tsc --project tsconfig.json && tsc-alias -p tsconfig.json",
}
```

or

```json
"scripts": {
  "build": "tsc && tsc-alias",
  "build:watch": "tsc && (concurrently \"tsc -w\" \"tsc-alias -w\")"
}
```

## Issues

If you have an issue, please create one. But, before:

- try to check the [FAQ.](https://github.com/justkey007/tsc-alias/discussions/110)
- try to check if there are any related issues
- try to run with `--debug` and check if config is correctly loaded and all sourcefiles are found.

## API

### Installation

```sh
npm install tsc-alias
```

### Usage

```typescript
import { replaceTscAliasPaths } from 'tsc-alias';

replaceTscAliasPaths(options?);
```

Here are all the available options:

     Option
     Description
     Default Value

       project, p
       path to tsconfig.json
       'tsconfig.json'

       watch
       Observe file changes
       false

       outDir
       Run in a folder leaving the "outDir" of the tsconfig.json (relative path to tsconfig)
       tsconfig.compilerOptions.outDir

       declarationDir
       Works the same as outDir but for declarationDir
       tsconfig.compilerOptions.declarationDir

       resolveFullPaths
       Attempt to replace incomplete import paths (those not ending in .js) with fully resolved paths (for ECMAScript Modules compatibility)
       false

       resolveFullExtension
       Allows you to specify the extension of incomplete import paths, works with resolveFullPaths
       '.js' | '.mjs' | '.cjs'

       silent
       Reduced terminal output. This is a deprecated option and no longer has any effect.
       true

       verbose
       Additional information is output to the terminal
       false

       debug
       Debug information is send to the terminal
       false

       replacers
       Files to import as extra replacers More info (https://github.com/justkey007/tsc-alias/discussions/73)
       []

       output
       The output object tsc-alias will send logs to.
       new Output(options.verbose)

       fileExtensions
       Overwrite file extensions tsc-alias will use to scan and resolve files.
       undefined

### Configuration via `tsconfig.json` Example

```json
{
  "compilerOptions": {
    ...
  },
  "tsc-alias": {
    "verbose": false,
    "resolveFullPaths": true,
    "replacers": {
      "exampleReplacer": {
        "enabled": true,
        "file": "./exampleReplacer.js"
      },
      "otherReplacer": {
        "enabled": true,
        "file": "./otherReplacer.js"
      }
    },
    "fileExtensions": {
      "inputGlob": "{js,jsx,mjs}",
      "outputCheck": ["js", "json", "jsx", "mjs"]
    }
  }
}
```

### Single file replacer

We can use tsc-alias in a single file, with a function that returns the modified contents.

We prepare the replacer with `prepareSingleFileReplaceTscAliasPaths()`, passing the same options that we would pass to `replaceTscAliasPaths()`. That will return a promise of a function that receives the file contents and path, and returns the transformed contents, synchronously.

```typescript
import { prepareSingleFileReplaceTscAliasPaths } from 'tsc-alias';

const runFile: SingleFileReplacer = await prepareSingleFileReplaceTscAliasPaths(options?);

function treatFile(filePath: string) {
  const fileContents = fs.readFileSync(filePath, 'utf8');
  const newContents = runFile({fileContents, filePath});
  // do stuff with newContents
}
```
