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TypeScript Best Practices for 2026

Valentine Omonya
2 min read
TypeScriptBest PracticesProgramming

Introduction

TypeScript continues to evolve and improve. Here are the best practices every developer should follow in 2026 to write better TypeScript code.

Use Strict Mode

Always enable strict mode in your tsconfig.json:

json
1{
2  "compilerOptions": {
3    "strict": true,
4    "noUncheckedIndexedAccess": true,
5    "exactOptionalPropertyTypes": true
6  }
7}

Quick Tip

Strict mode catches many common bugs at compile time, saving you hours of debugging.

Prefer unknown Over any

Instead of using any, prefer unknown for values with an uncertain type:

typescript
1// Bad - no type safety
2function processInput(input: any) {
3  input.toUpperCase(); // No error, but might crash at runtime
4}
5

6// Good - forces type checking
7function processInput(input: unknown) {
8  if (typeof input === "string") {
9    input.toUpperCase(); // Safe!
10  }
11}

Use Discriminated Unions

Discriminated unions are powerful for modeling state:

typescript
1type AsyncState<T> =
2  | { status: 'idle' }
3  | { status: 'loading' }
4  | { status: 'success'; data: T }
5  | { status: 'error'; error: Error };
6

7function handleState(state: AsyncState<User>) {
8  switch (state.status) {
9    case 'idle':
10      return <Placeholder />;
11    case 'loading':
12      return <Spinner />;
13    case 'success':
14      return <UserProfile user={state.data} />;
15    case 'error':
16      return <ErrorMessage error={state.error} />;
17  }
18}

Template Literal Types

Template literal types enable powerful string manipulation at the type level:

typescript
1type EventName = "click" | "focus" | "blur";
2type EventHandler = `on${Capitalize<EventName>}`;
3// Result: "onClick" | "onFocus" | "onBlur"

Use satisfies Operator

The satisfies operator ensures a value matches a type while preserving its literal type:

typescript
1const config = {
2  port: 3000,
3  host: "localhost",
4  debug: true,
5} satisfies Record<string, string | number | boolean>;
6

7// config.port is narrowed to `number`, not `string | number | boolean`

Conclusion

Following these TypeScript best practices will help you write code that is:

  • More type-safe and catches bugs early
  • More readable for your team
  • More maintainable in the long run

Keep coding safely.