EC
TS8030
TypeScriptERRORNotableStrictHIGH confidence

The type of a function declaration must match the function's signature.

Production Risk

Build will fail; resolve before shipping.

What this means

A strict mode error (TS8030): The type of a function declaration must match the function's signature.. This diagnostic is emitted by the TypeScript compiler when the type of a function declaration must match the function's signature..

Why it happens
  1. 1Incorrect TypeScript syntax or type usage
  2. 2Type mismatch between declared and actual value
How to reproduce

TypeScript compiler reports TS8030 during type checking.

trigger — this will error
trigger — this will error
// Triggers TS8030
// The type of a function declaration must match the function's signature.

expected output

error TS8030: The type of a function declaration must match the function's signature.

Fix

Address the TypeScript diagnostic

WHEN When this error is reported by the compiler

Address the TypeScript diagnostic
// Run the TypeScript compiler for details:
npx tsc --noEmit
// Use the TypeScript playground to test your code:
// https://www.typescriptlang.org/play

Why this works

Review the full error message and location; the TypeScript handbook provides guidance on each error category.

Sources
Official documentation ↗

TypeScript Compiler Diagnostics

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