Error map
TS2379/TS2375: exactOptionalPropertyTypes error TypeScript: error TS2379: Argument of type '{ name: string; age: undefined; }' is not assignable to parameter of type 'User' with 'exactOptionalPropertyTypes: true'
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)
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 TS2353: Object literal may only specify known properties, and 'nmae' does not exist in type 'User'
An object literal has an extra (or misspelled) property not in the target type (excess property check).
TypeScript: error TS1005: ';' expected.
The parser hit a syntax error — missing punctuation, mismatched brackets, or an unsupported syntax for your TypeScript version.
TypeScript: error TS2740: Type '{ name: string; }' is missing the following properties from type 'User': id, email
An object doesn't provide all required properties of the target type.
TypeScript: error TS6133: 'x' is declared but its value is never read.
`noUnusedLocals`/`noUnusedParameters` flag an unused variable, import or parameter.
TypeScript: error TS1192: Module '"./utils"' has no default export.
You used `import x from "./mod"` but the module only has named exports.
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 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 (23)
AttributeError: 'X' object has no attribute 'y'
You accessed an attribute or method that doesn’t exist on that object type.
java.lang.ClassCastException: class A cannot be cast to class B
An object was cast to a type it isn’t.
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.
TypeError: Cannot convert undefined or null to object
Object.keys/entries/assign was called with undefined or null.
TypeError: Cannot assign to read only property 'x' of object
Code tried to modify a frozen object, a getter-only property, or immutable state.
TypeScript: error TS2551: Property 'lenght' does not exist on type 'string'. Did you mean 'length'?
A property name is misspelled (TypeScript suggests the closest valid one).
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.
TypeScript: error TS2352: Conversion of type 'string' to type 'number' may be a mistake because neither type sufficiently overlaps with the other
A type assertion (`as`) between unrelated types was rejected.
TypeScript: error TS2741: Property 'email' is missing in type '{ name: string; }' but required in type 'User'.
An object lacks one required property of the target type.
TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor
With strictPropertyInitialization on, a class property declared without ? or a default isn’t set in the constructor.
TS7006: Parameter 'x' implicitly has an 'any' type
A function parameter has no type annotation and TypeScript can’t infer one, which noImplicitAny (part of strict) forbids.
Next.js: Failed to compile. ./src/app/page.tsx 12:7 Error: 'x' is assigned a value but never used. @typescript-eslint/no-unused-vars
`next build` runs ESLint and fails the build on lint errors.
TypeError: x is not a function
You called something as a function, but its value is not a function (it’s undefined, a string, an object…).
Error [ERR_REQUIRE_ESM]: require() of ES Module not supported
CommonJS code used `require()` on a package that is ES-module-only (node-fetch 3, chalk 5, nanoid 4, got 12…).
SyntaxError: Cannot use import statement outside a module
An `import` statement ran in a context treated as CommonJS (Node without "type": "module", a browser script without type="module"…
SyntaxError: Identifier 'x' has already been declared
The same let/const/class name was declared twice in the same scope.
SyntaxError: await is only valid in async functions and the top level bodies of modules
await was used inside a function that isn’t async (or in a classic, non-module script).
SyntaxError: Unexpected identifier
The parser found a name where it expected punctuation — usually a missing comma, operator or quote.
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.
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.
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