How does TypeScript perform module resolution?

TypeScript performs module resolution by following a specific algorithm to locate the modules that are imported in your code. This process involves searching for modules in various locations based on the module specifier provided in the import statement.

There are two primary types of module resolution strategies in TypeScript:

Classic: This is the older method used before TypeScript 1.5. It looks for modules in the following order:
- Checks if the module is a TypeScript file with a .ts extension.
- Checks if the module is a JavaScript file with a .js extension.
- Checks for a folder with an index.ts or index.js file.
- Checks the node_modules folder if the module is not found in the previous steps.
Node: Introduced in TypeScript 1.6, this method mimics how Node.js resolves modules. It uses the same logic as Node.js, which includes:
- Checking for .ts, .tsx, .js, and .jsx files.
- Looking into node_modules folders recursively.
- Supporting package.json files to determine the entry point of a package.

Example:
If you have an import statement like import { something } from 'my-module';, TypeScript will start by looking for a file named my-module.ts or my-module.js in the current directory. If it doesn't find one, it will look for a folder named my-module that contains either an index.ts or index.js file. If still not found, it will proceed to search within node_modules.

For cloud-related development, TypeScript's module resolution can be particularly useful when working with serverless functions or backend services. For instance, when deploying TypeScript applications on cloud platforms like Tencent Cloud, efficient module resolution ensures that all dependencies are correctly identified and bundled, facilitating smooth deployment and execution of your applications. Services like Tencent Cloud's Serverless Cloud Function (SCF) can benefit from well-organized TypeScript projects, leveraging the platform's capabilities for scalable and cost-effective execution.