I am writing small project in React.JS. Every time I run : npm run start, it logs this:

Starting type checking and linting service...
Using 1 worker with 2048MB memory limit
Watching: /Users/John/Projects/myProject/src
Starting the development server...

ts-loader: Using [email protected] and /Users/John/Projects/myProject/tsconfig.json

No valid rules have been specified for TypeScript files

Compiled successfully!
You can now view book-viewer-test in the browser.
Local:            http://localhost:3000/

I have highlighted the line with the error. Everything works good, but I am afraid that it could have effect when project will be bigger and more plex.

What is this Warning/Error? How could I fix it?

Here is my tsconfig.json file:

{
  "pilerOptions": {
    "baseUrl": "./",
    "outDir": "build/dist",
    "module": "esnext",
    "target": "es5",
    "lib": ["es7", "dom"],
    "sourceMap": true,
    "allowJs": true,
    "jsx": "react",
    "moduleResolution": "node",
    "rootDir": "src",
    "forceConsistentCasingInFileNames": true,
    "noImplicitReturns": true,
    "noImplicitThis": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "suppressImplicitAnyIndexErrors": true,
    "noUnusedLocals": true,
    "experimentalDecorators": true
  },
  "exclude": [
    "node_modules",
    "build",
    "scripts",
    "acceptance-tests",
    "webpack",
    "jest",
    "src/setupTests.ts"
  ]
}

and there is tslint.json file:

{
  "jsRules": {
    "no-empty": true
  }
}

Thank you for your advice.

I am writing small project in React.JS. Every time I run : npm run start, it logs this:

Starting type checking and linting service...
Using 1 worker with 2048MB memory limit
Watching: /Users/John/Projects/myProject/src
Starting the development server...

ts-loader: Using [email protected] and /Users/John/Projects/myProject/tsconfig.json

No valid rules have been specified for TypeScript files

Compiled successfully!
You can now view book-viewer-test in the browser.
Local:            http://localhost:3000/

I have highlighted the line with the error. Everything works good, but I am afraid that it could have effect when project will be bigger and more plex.

What is this Warning/Error? How could I fix it?

Here is my tsconfig.json file:

{
  "pilerOptions": {
    "baseUrl": "./",
    "outDir": "build/dist",
    "module": "esnext",
    "target": "es5",
    "lib": ["es7", "dom"],
    "sourceMap": true,
    "allowJs": true,
    "jsx": "react",
    "moduleResolution": "node",
    "rootDir": "src",
    "forceConsistentCasingInFileNames": true,
    "noImplicitReturns": true,
    "noImplicitThis": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "suppressImplicitAnyIndexErrors": true,
    "noUnusedLocals": true,
    "experimentalDecorators": true
  },
  "exclude": [
    "node_modules",
    "build",
    "scripts",
    "acceptance-tests",
    "webpack",
    "jest",
    "src/setupTests.ts"
  ]
}

and there is tslint.json file:

{
  "jsRules": {
    "no-empty": true
  }
}

Thank you for your advice.

• javascript
• json
• reactjs
• typescript
• npm

4 Answers 4

The only TSLint rules you have apply to JavaScript files, not TypeScript ones. In order to lint TypeScript files, use rules instead of jsRules.

{
  "rules": {
    "no-empty": true
  }
}

You should check the versions your using probably nothing serious since there are no rules defined! Anyway if you have react, npm , node updated you should have an output like this more or less:

PS C:\React\my-app> npm run start

> [email protected] start C:\React\my-app
> react-scripts start
Starting the development server...
Compiled successfully!

You can now view my-app in the browser.

  Local:            http://localhost:3000/
  On Your Network:  http://192.168.1.67:3000/

Note that the development build is not optimized.
To create a production build, use npm run build.

This looks like a TSLint error. Do you have TSLint installed? Mind sharing your package.json? Do you have a tslint.json and if so, can you share it? (Creating a tslint.json with the rules you want might already solve it.)

Solution is to add this to tslint.json in your project directory:

{
    "rules": {
        "no-empty": false
    },
    "jsRules": {
        "no-empty": true
    }
 }