Unlocking Efficient Type Checking with TypeRunner

Understanding the Performance Issue

Traditional type checking methods using tsc can be slow, especially for large code bases. This can lead to delayed feedback from the compiler, hindering the development experience.

How TypeRunner Works

TypeRunner extracts type information from TypeScript code and compiles it to bytecode. This bytecode is then executed in a custom virtual machine for type checking. This approach allows TypeRunner to perform type checking independently of the language, making it a versatile tool.

interface UserData {
  id: number;
  name: string;
}

Use Cases for TypeRunner

• Type Checking in Non-JavaScript Environments: TypeRunner enables type checking in environments where tsc is not available.
• Replacing DSLs: TypeRunner can replace domain-specific languages (DSLs) used for data modeling with TypeScript interfaces and types.
• Improving Type Checking Performance: TypeRunner significantly improves type checking speed, making it an attractive option for large code bases.

Demonstrating TypeRunner in Action

Let’s create a simple model of user data and use TypeRunner to perform type checking. We’ll define a TypeScript source file, main.ts, and use TypeRunner to check for type errors.

Cloning the TypeRunner Repo and Building the Docker Image

To get started with TypeRunner, we need to clone the repo and build the Docker image. This will allow us to run TypeRunner in a containerized environment.

$ git clone https://github.com/typerunner/typerunner.git
$ cd typerunner
$ docker build -t typerunner.

Using TypeRunner for Type Checking

Once the Docker image is built, we can use TypeRunner to perform type checking on our main.ts file. We’ll mount the source file into the container and run TypeRunner to check for type errors.

$ docker run -v $(pwd)/main.ts:/app/main.ts typerunner

Comparing TypeRunner with Deno and tsc

We’ll compare the output of TypeRunner with Deno and tsc to demonstrate the differences in type checking results.

Handling Complex Types and Current Limitations

TypeRunner can handle complex types, but it has some limitations, such as not supporting import statements and Deno’s global namespace.

Advantages of TypeRunner

TypeRunner offers significant performance benefits over traditional type checking methods. Its ability to compile TypeScript to bytecode and execute it in a custom virtual machine makes it an attractive option for large code bases.