TypeScript 对module resolve的顺序

First, looking up a file, then looking up an applicable folder.

 

 import { b } from "moduleB" in source file /root/src/moduleA.ts would result in the following lookups:

 

1. /root/src/node_modules/moduleB.ts =========》一、file
2. /root/src/node_modules/moduleB.tsx
3. /root/src/node_modules/moduleB.d.ts
4. /root/src/node_modules/moduleB/package.json (if it specifies a "types" property)
5. /root/src/node_modules/@types/moduleB.d.ts  // ====》二、@types
6. /root/src/node_modules/moduleB/index.ts   // ======》 三、modules folder
7. /root/src/node_modules/moduleB/index.tsx
8. /root/src/node_modules/moduleB/index.d.ts
   
   
9. /root/node_modules/moduleB.ts
10. /root/node_modules/moduleB.tsx
11. /root/node_modules/moduleB.d.ts
12. /root/node_modules/moduleB/package.json (if it specifies a "types" property)
13. /root/node_modules/@types/moduleB.d.ts
14. /root/node_modules/moduleB/index.ts
15. /root/node_modules/moduleB/index.tsx
16. /root/node_modules/moduleB/index.d.ts
    
    
17. /node_modules/moduleB.ts
18. /node_modules/moduleB.tsx
19. /node_modules/moduleB.d.ts
20. /node_modules/moduleB/package.json (if it specifies a "types" property)
21. /node_modules/@types/moduleB.d.ts
22. /node_modules/moduleB/index.ts
23. /node_modules/moduleB/index.tsx
24. /node_modules/moduleB/index.d.ts

 

Don’t be intimidated by the number of steps here

- TypeScript is still only jumping up directories twice at steps (9) and (17). This is really no more complex than what Node.js itself is doing.