map a path to a subfolder in tsconfig

Mapping a Path to a Subfolder in tsconfig

When working with TypeScript, it is common to have a project structure where your source files are organized in subfolders. However, by default, TypeScript assumes that all source files are located in the root directory. In order to properly map a path to a subfolder in tsconfig, you need to make use of the paths option.

The paths option allows you to specify custom mappings from module names to locations on the file system. This is particularly useful when you want to map a path to a subfolder in your project.

Solution 1: Using the paths option in tsconfig.json

The first solution involves modifying the tsconfig.json file to include the desired path mapping. Here’s an example:

{
  "compilerOptions": {
    "baseUrl": "./",
    "paths": {
      "@subfolder/*": ["./src/subfolder/*"]
    }
  }
}

In this example, we have specified a path mapping for the @subfolder/* module name, which maps to the ./src/subfolder/* directory. The baseUrl option is set to the root directory of the project.

With this configuration, you can now import modules from the subfolder using the @subfolder module name. For example:

import { SomeModule } from '@subfolder/some-module';

This will correctly resolve the module from the subfolder.

Solution 2: Using the paths option in tsconfig.json with wildcards

If you have multiple subfolders that you want to map, you can use wildcards in the path mapping. Here’s an example:

{
  "compilerOptions": {
    "baseUrl": "./",
    "paths": {
      "@subfolder/*": ["./src/subfolder/*"],
      "@anotherfolder/*": ["./src/anotherfolder/*"]
    }
  }
}

In this example, we have added another path mapping for the @anotherfolder/* module name, which maps to the ./src/anotherfolder/* directory. You can add as many path mappings as you need.

With this configuration, you can import modules from both subfolders using the respective module names. For example:

import { SomeModule } from '@subfolder/some-module';
import { AnotherModule } from '@anotherfolder/another-module';

Both of these imports will correctly resolve the modules from their respective subfolders.

Conclusion

Mapping a path to a subfolder in tsconfig is essential when working with TypeScript projects that have a complex folder structure. By using the paths option in the tsconfig.json file, you can easily map module names to their corresponding locations on the file system.

Remember to update the baseUrl option to reflect the root directory of your project. With the correct path mappings, you can import modules from subfolders without any issues.

Happy coding!