在具有.js文件的现有项目中使用打字稿

Question

I have an existing NodeJS project, which has .js files, written in ES6 . Now I want to start using typescript in the existing project. How should I go about? Should I just start with .ts files in the same directory structure?

One of the problems I noticed, is that tsc only considers the .ts files. So for tsconfig.json which looks something like:

    {
    "compilerOptions": {
        "target": "es2015",
        "outDir": "./dist",
        "allowJs": true,
        "module": "commonjs",
        "noEmitOnError": false,
        "noImplicitAny": false,
        "strictNullChecks": true
    },
    "include": [
        "app/"
    ] 
}

will only convert the .ts files and leave the other .js files that form the majority of the project. How should I approach this?

Answer 1

First you need to add typescript as developer dependency by using this command to your project directory

npm i --save-dev typescript

Then you convert all .js files to .ts files and then run this command. <your_project_path>/node_modules/.bin/tsc -p '<your_project_path>/tsconfig.json'

Remember to give absolute paths so that there won't be any ambiguity

After you run this command it will create .js files in your ./dist folder. This is your output path given in "outDir": "./dist in your tsconfig.json file. It will keep the same directory structure which was in your app but with .js and .map files.

I would recommend to use app/ folder to write all your code in typescript and while deploying run javascript files from ./dist folder ignoring the .map files.