Typescript Aliases Transform

Small tool to parse & play with Typscript aliases.

Path Checking:

• If it contains an alias
• If it can be aliased

Path Transformation:

• Resolve full path from aliased path
• Apply aliases to a filename

Aliases list conversion:

• Generate webpack aliases
• Generate module-alias resolver

/!\ WARNING: This package is not enough mature to be used in production.

Installation

npm install --save ts-alias

API

type AliasList = { 
    [alias: string]: { pathnames: string[], exact: boolean }
};

type TsAliasList = { [alias: string]: string[] };

type ModuleAliasList = { [alias: string]: string | Function };

type TWebpackExternals = (data: { request: string }, callback: (err: undefined, result: string) => void) => void;

class TsAlias {

    constructor( input: string | AliasList, private debug: boolean = false );

    // Original typescript aliases
    public typescript: TsAliasList;
    // Normalized list
    public list: AliasList;

    // Path transformation
    public apply(filename: string, strict?: false): string;
    public apply(filename: string, strict: true): string | null;
    public apply(filename: string, strict?: boolean): string | null;

    public containsAlias(request: string): boolean;

    public realpath(request: string, strict?: false): string;
    public realpath(request: string, strict: true): string | null;
    public realpath(request: string, strict?: boolean): string | null;

    public isAliased(filename: string): boolean;
    
    // List transformation
    public forWebpack( modulesPath?: string ): { aliases: TsAliasList };
    public forWebpack( modulesPath: string, nodeExternals: true ): { 
        aliases: TsAliasList, 
        externals: TWebpackExternals 
    };
    
    public forModuleAlias( enableCache: boolean = true ): ModuleAliasList;

}

Usage Example

import Aliases from 'ts-alias';
const aliases = new Aliases();

// Generate list for module-alias
import moduleAlias from 'module-alias';
moduleAlias.addAliases( aliases.forModuleAlias() )

// Generate list for webpack
module.export = {
    ...
    resolve: {
        alias: aliases.forWebpack(),
    }
    ...
}

// Transform / check paths
console.log( 

    aliases.typescript,
    // { "@server": ["./src/server/*"] }
    
    aliases.apply('/home/dopamyn/www/project/src/server/models'),
    // "@server/models"
    aliases.apply('/home/dopamyn/www/project/src/server/repositories'),
    // "/home/dopamyn/www/project/src/server/repositories"
    
    aliases.isAliased('/home/dopamyn/www/project/src/server/repositories'),
    // true
    aliases.isAliased('/home/dopamyn/www/project/src/common'),
    // false
    
    aliases.realpath('@server/models'),
    // "/home/dopamyn/www/project/src/server/models"
    aliases.realpath('@client/components'),
    // "@client/components"
    
    aliases.containsAlias('@server/models'),
    // true
    aliases.containsAlias('@client/components'),
    // false
    
);

TODO

• Better path resolving (traverse extends)
• Strict types checking
• Tests