EC
TS4056
TypeScriptERRORNotableDeclarationHIGH confidence

Return type of method from exported interface has or is using name 'X' from p...

Production Risk

Build will fail; resolve before shipping.

What this means

A declaration emit error (TS4056): Return type of method from exported interface has or is using name 'X' from private module 'X'.. This diagnostic is emitted by the TypeScript compiler when return type of method from exported interface has or is using name 'X' from private module '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 TS4056 during type checking.

trigger — this will error
trigger — this will error
// Triggers TS4056
// Return type of method from exported interface has or is using name 'X' from private module 'X'.

expected output

error TS4056: Return type of method from exported interface has or is using name 'X' from private module 'X'.

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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