While learning Typescript, I encountered many issues that were either recurring or difficult to solve. Because of this, I decided to share them in this post so that I could have access to the most common Typescript errors and their solutions. Since these are my first steps in learning TypeScript, feel free to share your insights and correct me if you see a solution applied incorrectly.
I will occasionally add more typescript errors to this post, hoping to save time and spare at least one of you the frustration and effort of dealing with them!
TS2580 – Cannot find name ‘require’
Error 🆘 (TS2580)
error TS2580: Cannot find name 'require'. Do you need to install type definitions for node? Try `npm i --save-dev @types/node`.
Reason 🔬
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As the error description clearly suggests, Typescript needed @types/node to successfully finish the compilation.
Solution ✅
Running npm i --save-dev @types/node solves this issue
TS7006 – Parameter ‘res’ implicitly has an ‘any’ type.
Error 🆘
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error TS7006: Parameter 'res' implicitly has an 'any' type.6 app.get('/', (req, res) => {
Reason 🔬
I was building a project and had the following boilerplate code included
const express = require('express');
const app = express();
app.get('/', (req, res) => {
res.send('Hello World!');
})
My tsconfig.json file had compilerOptions: {"strict": true } set, so it was basically telling TS not to accept type any for its parameters. strict: true is a shortcut for applying strict rules, including the noImplicitAny rule.
If you’re running into this error while setting up a backend project, it usually means Express is working but TypeScript isn’t fully configured yet. In that case, you might find it helpful to follow a complete walkthrough on setting up an Express.js server with Typescript from scratch, including the correct typings and project structure.
Solution ✅
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To solve this issue, we need to install @types/express by running
npm install --save-dev @types/express
In addition, we will refactor our code to use explicit types for our function parameters and constants.
import express, { Express, Request, Response } from 'express';
const app: Express = express();
const port = 3004;
app.get('/', (req: Request, res: Response) => {
res.send('Hello World!');
})
app.listen(port, () => {
console.log(`Example app listening on port ${port}`);
});
TS7016 – Could not find a declaration file for module X.file Y implicitly has an ‘any’ type
Error 🆘
error TS7016: Could not find a declaration file for module X.file Y implicitly has an 'any' type.
Reason 🔬
This error occurs because module X may not include TypeScript type definitions by default, and type definitions for module X haven’t been installed or declared in your project.
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Solution ✅
If there are community-maintained type definitions, e.g @types/module-x install them, and this will solve your issue.
Another way to overcome this error is to create a custom-type declaration if option 1 is unavailable.
TS18003 – No inputs were found in config file <filename>
While initializing my project, I saw this error when running npx tsc
Error 🆘
error TS18003: No inputs were found in config file '/server-project/tsconfig.json'. Specified 'include' paths were '["**/*"]' and 'exclude' paths were '[]'.
Reason 🔬
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Typescript needs at least one ts file in a project to compile. I was seeing this error cause I was too eager to run the tc compiler without any .tsc files include in my project.
Solution ✅
Just add a .ts file, even an empty one, for starters, in your project.
How to prevent common Typescript errors in new projects
Many Typescript errors appear not because something is broken, but because the project setup is incomplete. A few small habits can prevent most of the issues listed above.
First, always install type definitions alongside your dependencies. If you’re using node, Express, or other popular Javascript libraries, there’s usually a corresponding @types/* package available. Installing these early prevents many implicit any and missing type errors.
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Second, review your tsconfig.json before writing too much code. Options like strict, noImplicitAny, and moduleResolution have a big impact on how Typescript behaves. Enabling strict mode early is usually easier than fixing hundreds of errors later.
Finally, don’t silence Typescript errors just to make the project compile. Typescript is most useful when you understand why an error exists — fixing the root cause often prevents the same issue from showing up again in future projects.
Common beginner mistakes when working with Typescript
Running the Typescript compiler too early is a frequent issue. Typescript expects at least one valid .ts file, so initializing a project without source files will often result in misleading errors.
Another common mistake is ignoring Typescript warnings just to “make it work.” While this may speed things up short-term, it usually leads to repeated issues later. Treat TypeScript errors as guidance, not obstacles.
Finally, relying too heavily on any defeats the purpose of using Typescript in the first place. If you find yourself adding any often, it’s usually a sign that some types or definitions are missing.
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If you’re experiencing a recurring error that’s frustrating you, please mention it in the comments section so we can address it and help others who might be facing the same issue.
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