How to fix error TS7016: Could not find a declaration file for module ‘XYZ’. ‘file.js’ implicitly has an ‘any’ type

If you’re using TypeScript you might have run into this error before. The second part of the error says:

Try `npm install @types/XYZ` if it exists or add a new declaration (.d.ts) file containing `declare module 'XYZ';

If XYZ is a direct dependency of your project, you can follow the instructions from the error message and run npm install @types/XYZ.

Sometimes the types might not be available and the npm install command fails. In that case, you can use the second option and declare the module.

Here’s how I usually do that.

1. Create a folder called typings
2. Create a file in that folder called index.d.ts
3. Declare the module(s) like this:

declare module 'XYZ';

Lastly, you also need to add the path to your index.d.ts in the tsconfig.json file under the typeRoots element, like this:

"typeRoots": [
  "./typings",
  "./node_modules/@types/"
]

But ‘XYZ’ is not a direct dependency of my project

I’ve started seeing this error when I upgraded eslint to 7.4.0. And to make things even more complicated:

1. It was only happening during the CI build. I tried to reproduce the issue locally on a “clean” environment and I couldn’t get it to fail.
2. XYZ was not my direct dependency. My project has a dependency on “ABC” and “ABC” has a dependency on “XYZ”

It felt weird to install types for 3rd or n-party dependency and it didn’t make sense to me (I might be wrong though!).

Instead of ratholing on that, I added the following statement to thetsconfig.json file to disable the ‘any’ type errors:

"noImplicitAny": false

Note that disabling this will disable the rule for your project as well. But at least your build will be working, until the n-th dependency fixes this issue in their codebase.