How switching to TypeScript improved code quality and reduced bugs in our projects.
"Cannot read property 'x' of undefined" - every JavaScript developer has seen this error. In production. At 3 AM. After a customer reported that "the site doesn't work". TypeScript isn't perfect, but it eliminates an entire class of such problems.
-40%
runtime bugs after TypeScript migration (our data)
What TypeScript provides in practice?
JavaScript
function getUser(id) {
return fetch('/api/users/' + id)
.then(r => r.json());
}
// What does it return? Unknown.
// What fields? Unknown.
TypeScript
interface User {
id: number;
name: string;
email: string;
}
async function getUser(id: number): Promise {
return (await fetch(`/api/users/${id}`)).json();
}
// Everything clear. IDE autocompletes.
5 reasons we switched to TypeScript
1
Autocomplete on steroids
You don't need to remember field names. IDE suggests. You don't need to search docs - types ARE documentation.
2
Safe refactoring
Change a field name in interface - TypeScript shows ALL places that break. In JS? Ctrl+F and hope.
Results after migration (50k+ lines project)
-40%
runtime errors
-60%
onboarding time
+30%
refactoring speed
Planning TypeScript migration?
We'll help plan the migration, train your team, and establish typing standards for your project.