EC
TS90063
TypeScriptERRORNotableConfigHIGH confidence

Add return type 'X'

Production Risk

Build will fail; resolve before shipping.

What this means

A TypeScript diagnostic (TS90063): Add return type 'X'. This diagnostic is emitted by the TypeScript compiler when add return type 'X'.

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

TypeScript compiler reports TS90063 during type checking.

trigger — this will error
trigger — this will error
// Triggers TS90063
// Add return type 'X'

expected output

error TS90063: Add return type 'X'

Fix

Fix the tsconfig.json option

WHEN When a compiler option is invalid or missing

Fix the tsconfig.json option
// tsconfig.json
{
  "compilerOptions": {
    // Review and correct the flagged option
  }
}
// Run: npx tsc --showConfig to see effective config

Why this works

TypeScript validates tsconfig.json options; check the official tsconfig reference for valid values.

Sources
Official documentation ↗

TypeScript Compiler Diagnostics

Content generated with AI assistance and reviewed for accuracy. Found an error? hello@errcodes.dev

← All TypeScript errors