EC
TS1538
TypeScriptERRORNotableSyntaxHIGH confidence

Unicode escape sequences are only available when the Unicode (u) flag or the ...

Production Risk

Build will fail; resolve before shipping.

What this means

A syntax error (TS1538): Unicode escape sequences are only available when the Unicode (u) flag or the Unicode Sets (v) flag is set.. This diagnostic is emitted by the TypeScript compiler when unicode escape sequences are only available when the Unicode (u) flag or the Unicode Sets (v) flag is set..

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

TypeScript compiler reports TS1538 during type checking.

trigger — this will error
trigger — this will error
// Triggers TS1538
// Unicode escape sequences are only available when the Unicode (u) flag or the Unicode Sets (v) flag is set.

expected output

error TS1538: Unicode escape sequences are only available when the Unicode (u) flag or the Unicode Sets (v) flag is set.

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

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

← All TypeScript errors