If you are having difficulty in resolving the error “Could not find declaration file for module ‘lodash’ #”, this article will help you to do it. Information related to this error will be discussed below.
Why did you get the error message “Could not find declaration file for module ‘lodash’ #“
To illustrate, let me describe why the error occurs.
import _ from 'lodash'; //...Your code
Output:
Could not find a declaration file for module 'lodash'. '/User/Admin/Desktop/typescript_tutorial/node_modules/lodash/index.js' implicitly has an 'any' type.This error occurred because TypeScript could not find a matching declaration for the ‘lodash‘ module.
Solutions to fix this problem
Here are some solutions you can apply to get rid of this error.
Install the types for the module
In general, open the terminal and run this command to install the types for the module you want.
npm install --save-dev @types/module-nameMake sure you replace “module-name” with the name of the module you are trying to install. For the particular case in this article, we will install the types for the ‘lodash’ module.
npm install --save-dev @types/lodashReplace ‘import‘ statement with ‘require‘
After installation, you can start importing the module into the file you need to use. However, if you use the import statement but it doesn’t work, you can try using require.
These two statements have exactly the same function, but sometimes your computer works with one and not the other.
Try using the below statement instead of the import statement:
var _ = require('lodash')Declare the module in a ‘.d.ts’ file
If you have installed and imported as instructed above and still get the error, try declaring the module in a file of ‘.d.ts‘ format.
The reason you need to do this is that maybe the module you are trying to use from a third party does not provide typings.
To do that, create a ‘.d.ts‘ file in the same directory as your regular ‘.ts‘ files. Simply put ‘.d.ts‘ and ‘.ts‘ files are at the same level in your project structure.
For instance, I created a file named ‘modules.d.ts‘. Let’s see how we declare the module in this file.
modules.d.ts (Option 1):
declare module 'module-name';
modules.d.ts (Option 2):
declare module 'module-name' {
export function getMessage(): string;
}Usually, we will use the first option. In case you want to define the type for your package, then choose the second option.
Summary
You have been provided with relevant information about the error “Could not find declaration file for module ‘lodash’ #” and how to fix it. That’s all I want to cover in this article. I hope this is the information you are looking for to solve your problem.
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My name’s Christopher Gonzalez. I graduated from HUST two years ago, and my major is IT. So I’m here to assist you in learning programming languages. If you have any questions about Python, JavaScript, TypeScript, Node.js, React.js, let’s contact me. I will back you up.
Name of the university: HUST
Major: IT
Programming Languages: Python, JavaScript, TypeScript, Node.js, React.js