I am trying add typings for our Javascript files at work while we are in the process of converting to Typescript. However, I can not get the declaration files to be recognized.
Here is my file structure
Foo.js
module.exports = function Foo() {
return 'Bar';
};
index.d.ts
export = Foo;
declare function Foo(): string;
index.ts
import Foo = require('./js/Foo')
console.log(Foo());
tsconfig.json
{
"compilerOptions": {
"typeRoots": ["./typings"],
"target": "es5",
"strict": true,
"baseUrl": "./",
"paths": {
"*": ["typings/*"]
}
}
}
package.json
{
"name": "fail",
"version": "1.0.0",
"description": "",
"main": "index.ts",
"scripts": {
"tsc": "tsc"
},
"author": "",
"license": "MIT",
"dependencies": {
"typescript": "^3.1.4"
}
}
Here is repo to reproduce my problem
https://github.com/erisman20/typings_help
Edit: Here is there error I get
error TS7016: Could not find a declaration file for module './js/Foo.js'. '....../js/Foo.js' implicitly has an 'any' type.
The only ways to provide declarations for a relative import such as './js/Foo'
are to actually have the declaration file at the import path (plus .d.ts
or /index.d.ts
) or to have it virtually at the import path based on your rootDirs
option. Neither typeRoots
nor baseUrl
/paths
comes into play in this scenario: baseUrl
/paths
only affects module resolution for "non-relative" paths, and typeRoots
can be used to get TypeScript to load files but does not affect the relationship between import paths and files at all.
The simplest solution would be to put a Foo.d.ts
file in the same directory as Foo.js
. If you want to keep the typings in a separate directory, then you can add "rootDirs": ["js", "typings"]
to tsconfig.json
. That change is enough to make your example work for me, though I find it confusing to have corresponding Foo.js
and Foo/index.d.ts
files and would encourage you to be consistent in your use of subdirectories, i.e., either switch to Foo/index.js
on the JavaScript side or switch to Foo.d.ts
on the TypeScript side.