Author: John Au-Yeung

Sometimes, we want to import all types with TypeScript.

In this article, we’ll look at how to import all types with TypeScript.

How to import all types with TypeScript?

To import all types with TypeScript, we can do a namespace import.

For instance, we write

import * as foo from "./otherClass";

to import all members of the ./otherClass module as foo.

Then we can access any member of it from foo like

foo.bar

where bar is an exported member from ./otherClass.

Conclusion

To import all types with TypeScript, we can do a namespace import.

Sometimes, we want to create model classes in TypeScript.

In this article, we’ll look at how to create model classes in TypeScript.

How to create model classes in TypeScript?

To create model classes in TypeScript, we can create interfaces.

For instance, we write

interface IDonutChartModel {
  dimension: number;
  innerRadius: number;
}

const donut: IDonutChartModel = {
  dimension: 1,
  innerRadius: 2,
};

to create the IDonutChartModel interface.

Then we create the donut variable of type IDonutChartModel and assign it an object with content that matches the properties and data types of each property listed in the IDonutChartModel interface.

Conclusion

To create model classes in TypeScript, we can create interfaces.

Sometimes, we want to install and run TypeScript locally in npm.

In this article, we’ll look at how to install and run TypeScript locally in npm.

How to install and run TypeScript locally in npm?

To install and run TypeScript locally in npm, we can install the typescript package as a dev dependency.

To install it, we run

npm i typescript --save-dev

Then we can add the tsc script into package.json with

{
  "name": "foo",
  "scripts": {
    "tsc": "tsc"
  },
  //...
}

And then we can run npm run tsc to run tsc in our project.

Conclusion

To install and run TypeScript locally in npm, we can install the typescript package as a dev dependency.

Sometimes, we want to fix the "index.d.ts is not a module" error when importing the webrtc module with TypeScript.

In this article, we’ll look at how to fix the "index.d.ts is not a module" error when importing the webrtc module with TypeScript.

How to fix the "index.d.ts is not a module" error when importing the webrtc module with TypeScript?

To fix the "index.d.ts is not a module" error when importing the webrtc module with TypeScript, we can set the types property in tsconfig.json to ["webrtc"].

To do this, we write

{
  "compilerOptions": {
    "target": "es5",
    "sourceMap": true,
    "noImplicitAny": true,

    "types": ["webrtc"]
  },
  "exclude": ["node_modules"]
}

in tsconfig.json.

We add the types property in the compilerOptions object property.

Then we can use webrtc without importing it in our project files since this will let the TypeScript compiler know that the webrtc members are available globally.

Conclusion

To fix the "index.d.ts is not a module" error when importing the webrtc module with TypeScript, we can set the types property in tsconfig.json to ["webrtc"].

Sometimes, we want to read and write a text file in TypeScript.

In this article, we’ll look at how to read and write a text file in TypeScript.

How to read and write a text file in TypeScript?

To read and write a text file in TypeScript, we should install the @types/node package to add the typings for core Node modules.

To install it, we run

npm i @types/node

to add the node.d.ts file into our project which has the typings for the core Node modules.

Then we can us the fs.readFileSync method to read a file by writing

import * as fs from "fs";
const f = fs.readFileSync("foo.txt", "utf8");

to call readFileSync with the path of the file and the encoding of the file to return the file.

Conclusion

To read and write a text file in TypeScript, we should install the @types/node package to add the typings for core Node modules.