Specifying files for compilation

There are several ways to tell the TypeScript compiler which files to process. The simplest method is to explicitly list the files in the files field:

{
  "compilerOptions": {
    ...
  },
  "files": ["product.ts", "orderDetail.ts"]
}

However, that approach is difficult to maintain as our code base grows. A more maintainable approach is to define file patterns for what to include and exclude with the include and exclude fields.

The following example looks at the use of these fields:

1. Let's add the following include fields, which tell the compiler to compile TypeScript files found in the src folder and its subfolders:

{
  "compilerOptions": {
    ...
  },
  "include": ["src/**/*"]
}

1. At the moment, our source files aren't in a folder called src, but let's run a compile anyway:

tsc

1. As expected, we get No inputs were found in the config file... from the compiler.

Let's create an src folder and move orderDetail.ts into this folder. If we do a compile again, it will successfully find the files and do a compilation.

So, we have lots of options for adapting the TypeScript compiler to our particular situation. Some options, such as --noImplicitAny, force us to write good TypeScript code. We can take the checks on our code to the next level by introducing linting into our project, which we'll look at in the next section.