Error map
TS2393: Duplicate function implementation TypeScript: error TS2393: Duplicate function implementation.
TypeScript · layer 1, On your device
Centre: this error. First ring: errors it is linked with (8). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (8)
TypeScript: error TS2366: Function lacks ending return statement and return type does not include 'undefined'.
A function with a declared return type can reach its end without returning on some path.
TypeScript: error TS2451: Cannot redeclare block-scoped variable 'name'.
A `let`/`const`/`class` name was declared twice in the same scope — often because files are global scripts sharing one scope.
TypeScript: error TS2300: Duplicate identifier 'Foo'.
The same name is declared twice in the same scope (or in merged global declarations).
TypeScript: error TS2349: This expression is not callable. Type 'X' has no call signatures.
You called something TypeScript believes isn't a function (a union without compatible signatures, a module namespace, an object).
TypeScript: error TS2554: Expected 2 arguments, but got 1.
A call passes too few or too many arguments.
TypeScript: error TS2769: No overload matches this call. Overload 1 of 2, '(a: string): void', gave the following error.
A call matched none of the function's overload signatures.
TypeScript: error TS1005: ';' expected.
The parser hit a syntax error — missing punctuation, mismatched brackets, or an unsupported syntax for your TypeScript version.
TypeScript: error TS2307: Cannot find module './App.vue' or its corresponding type declarations.
TypeScript doesn't know what a `.vue` import is without a shim or Volar/`vue-tsc`.
Two steps away (22)
TS2322: Type 'X' is not assignable to type 'Y'
You assigned a value whose type doesn’t match the declared type of the variable, property or return value.
TypeScript: error TS2367: This comparison appears to be unintentional because the types '"a" | "b"' and '"c"' have no overlap.
You compare two values whose types can never be equal.
TypeScript: error TS2454: Variable 'x' is used before being assigned.
Control flow shows a path where the variable is read before any assignment.
ReferenceError: x is not defined
Code refers to a variable or function name that doesn’t exist in the current scope.
SyntaxError: Identifier 'x' has already been declared
The same let/const/class name was declared twice in the same scope.
ReferenceError: Cannot access 'x' before initialization
A let/const/class was used before its declaration line ran (temporal dead zone) — often a circular import.
TS2304: Cannot find name 'x'.
TypeScript doesn’t know an identifier — a missing import, missing type definitions (e.g. for Node or Jest globals), or a typo.
TypeScript: error TS2403: Subsequent variable declarations must have the same type. Variable 'x' must be of type 'string', but here has type 'number'.
A `var` was redeclared with a different type (or global declarations conflict).
TypeScript: error TS1128: Declaration or statement expected.
The parser found a token where a declaration or statement should start — usually stray braces/parentheses or code outside a funct…
TypeScript: error TS2604: JSX element type 'Foo' does not have any construct or call signatures.
You used something as a JSX component that TypeScript doesn't see as a component (not a function/class returning JSX).
TypeScript: error TS2693: 'User' only refers to a type, but is being used as a value here.
You used an interface/type alias where a runtime value is needed.
TypeScript: error TS1259: Module '"express"' can only be default-imported using the 'esModuleInterop' flag
You default-import a CommonJS module that uses `export =`, but `esModuleInterop` isn't enabled.
TS2345: Argument of type 'string | undefined' is not assignable to parameter of type 'string'.
A value’s type doesn’t match the function parameter — commonly a possibly-undefined value passed where a definite one is required.
TypeScript: error TS2589: Type instantiation is excessively deep and possibly infinite.
The compiler hit its recursion limit while evaluating a very complex or recursive generic type.
TypeScript: error TS1192: Module '"./utils"' has no default export.
You used `import x from "./mod"` but the module only has named exports.
TypeScript: error TS1208: 'index.ts' cannot be compiled under '--isolatedModules' because it is considered a global script file. Add an import, export, or an empty 'export {}' statement
With `isolatedModules`, every file must be a module (have an import or export).
SyntaxError: Unexpected token '<' (HTML served instead of JavaScript)
The browser loaded a .js file but received HTML (an error page or the SPA index.html).
SyntaxError: Unexpected end of input
The parser reached the end of the code (or JSON) while still expecting more — a missing } ) ] or empty JSON.
SyntaxError: missing ) after argument list
A function call’s parentheses are unbalanced — often an unescaped quote or a missing comma/plus.
TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts"
Node tried to run a TypeScript file as ESM without a TypeScript loader.
TS2307: Cannot find module 'x' or its corresponding type declarations.
TypeScript can’t resolve the import — the package isn’t installed, the path alias isn’t configured, or there are no types.
TS7016: Could not find a declaration file for module 'x'. 'x.js' implicitly has an 'any' type.
The JavaScript package has no TypeScript types bundled and no @types package installed.
Map another error
Popular: 500403400ORA-009331064Critical errorFileNotFoundException assemblyTypeError