Module resolution: ambient JSON wildcard module doesn't override `resolveJsonModule` typing

Nobody has claimed this yet.

### Demo Repo

https://github.com/niedzielski/2025-12-23-tsc-resolve-json-ambient-wildcard

### Which of the following problems are you reporting?

The module specifier resolves to the right file, but something about the types are wrong

### Demonstrate the defect described above with a code sample.

When `resolveJsonModule` is set, the imported JSON file's typing is used instead of the ambient module typing.

```ts
// schema-decl.d.ts
declare module '*.schema.json' {
const json: import("./schema.js").Schema
export default json
}
```

```ts
// index.ts
// Typed as JSON interpretation from file instead of ambient module.
import schemaJSON from './instance.schema.json' with { type: 'json' }
```

```jsonc
// tsconfig.json
{
"compilerOptions": {
"module": "esnext",
"moduleResolution": "bundler",
"resolveJsonModule": true,
"noEmit": true
}
}
```

### Run `tsc --showConfig` and paste its output here
```json
{
"compilerOptions": {
"module": "esnext",
"moduleResolution": "bundler",
"resolveJsonModule": true,
"noEmit": true,
"allowSyntheticDefaultImports": true,
"resolvePackageJsonExports": true,
"resolvePackageJsonImports": true
},
"files": [
"./index.ts",
"./schema-decl.d.ts",
"./schema.ts"
]
}
```

### Run `tsc --traceResolution` and paste its output here

```
======== Resolving module './instance.schema.json' from '/home/user/desk/foo/index.ts'. ========
Explicitly specified module resolution kind: 'Bundler'.
Resolving in CJS mode with conditions 'import', 'types'.
Loading module as file / folder, candidate module location '/home/user/desk/foo/instance.schema.json', target file types: TypeScript, JavaScript, Declaration, JSON.
File name '/home/user/desk/foo/instance.schema.json' has a '.json' extension - stripping it.
File '/home/user/desk/foo/instance.schema.d.json.ts' does not exist.
File '/home/user/desk/foo/instance.schema.json' exists - use it as a name resolution result.
======== Module name './instance.schema.json' was successfully resolved to '/home/user/desk/foo/instance.schema.json'. ========
======== Resolving module './schema' from '/home/user/desk/foo/index.ts'. ========
Explicitly specified module resolution kind: 'Bundler'.
Resolving in CJS mode with conditions 'import', 'types'.
Loading module as file / folder, candidate module location '/home/user/desk/foo/schema', target file types: TypeScript, JavaScript, Declaration, JSON.
File '/home/user/desk/foo/schema.ts' exists - use it as a name resolution result.
======== Module name './schema' was successfully resolved to '/home/user/desk/foo/schema.ts'. ========
======== Resolving module './schema.js' from '/home/user/desk/foo/schema-decl.d.ts'. ========
Explicitly specified module resolution kind: 'Bundler'.
Resolving in CJS mode with conditions 'import', 'types'.
Loading module as file / folder, candidate module location '/home/user/desk/foo/schema.js', target file types: TypeScript, JavaScript, Declaration, JSON.
File name '/home/user/desk/foo/schema.js' has a '.js' extension - stripping it.
File '/home/user/desk/foo/schema.ts' exists - use it as a name resolution result.
======== Module name './schema.js' was successfully resolved to '/home/user/desk/foo/schema.ts'. ========
File '/home/user/desk/foo/node_modules/typescript/lib/package.json' does not exist.
Found 'package.json' at '/home/user/desk/foo/node_modules/typescript/package.json'.
======== Resolving module '@typescript/lib-es5' from '/home/user/desk/foo/__lib_node_modules_lookup_lib.es5.d.ts__.ts'. ========
Explicitly specified module resolution kind: 'Node10'.
Loading module '@typescript/lib-es5' from 'node_modules' folder, target file types: TypeScript, Declaration.
Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.
Directory '/home/user/desk/foo/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-es5'
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-es5'
Directory '/home/user/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-es5'
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-es5'
Directory '/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-es5'
Loading module '@typescript/lib-es5' from 'node_modules' folder, target file types: JavaScript.
Searching all ancestor node_modules directories for fallback extensions: JavaScript.
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Directory '/node_modules' does not exist, skipping all lookups in it.
======== Module name '@typescript/lib-es5' was not resolved. ========
File '/home/user/desk/foo/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/home/user/desk/foo/node_modules/typescript/package.json' exists according to earlier cached lookups.
======== Resolving module '@typescript/lib-decorators' from '/home/user/desk/foo/__lib_node_modules_lookup_lib.decorators.d.ts__.ts'. ========
Explicitly specified module resolution kind: 'Node10'.
Loading module '@typescript/lib-decorators' from 'node_modules' folder, target file types: TypeScript, Declaration.
Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.
Directory '/home/user/desk/foo/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators'
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators'
Directory '/home/user/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators'
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators'
Directory '/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators'
Loading module '@typescript/lib-decorators' from 'node_modules' folder, target file types: JavaScript.
Searching all ancestor node_modules directories for fallback extensions: JavaScript.
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Directory '/node_modules' does not exist, skipping all lookups in it.
======== Module name '@typescript/lib-decorators' was not resolved. ========
File '/home/user/desk/foo/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/home/user/desk/foo/node_modules/typescript/package.json' exists according to earlier cached lookups.
======== Resolving module '@typescript/lib-decorators/legacy' from '/home/user/desk/foo/__lib_node_modules_lookup_lib.decorators.legacy.d.ts__.ts'. ========
Explicitly specified module resolution kind: 'Node10'.
Loading module '@typescript/lib-decorators/legacy' from 'node_modules' folder, target file types: TypeScript, Declaration.
Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.
Directory '/home/user/desk/foo/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators/legacy'
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators/legacy'
Directory '/home/user/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators/legacy'
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators/legacy'
Directory '/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-decorators/legacy'
Loading module '@typescript/lib-decorators/legacy' from 'node_modules' folder, target file types: JavaScript.
Searching all ancestor node_modules directories for fallback extensions: JavaScript.
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Directory '/node_modules' does not exist, skipping all lookups in it.
======== Module name '@typescript/lib-decorators/legacy' was not resolved. ========
File '/home/user/desk/foo/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/home/user/desk/foo/node_modules/typescript/package.json' exists according to earlier cached lookups.
======== Resolving module '@typescript/lib-dom' from '/home/user/desk/foo/__lib_node_modules_lookup_lib.dom.d.ts__.ts'. ========
Explicitly specified module resolution kind: 'Node10'.
Loading module '@typescript/lib-dom' from 'node_modules' folder, target file types: TypeScript, Declaration.
Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.
Directory '/home/user/desk/foo/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-dom'
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-dom'
Directory '/home/user/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-dom'
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-dom'
Directory '/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-dom'
Loading module '@typescript/lib-dom' from 'node_modules' folder, target file types: JavaScript.
Searching all ancestor node_modules directories for fallback extensions: JavaScript.
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Directory '/node_modules' does not exist, skipping all lookups in it.
======== Module name '@typescript/lib-dom' was not resolved. ========
File '/home/user/desk/foo/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/home/user/desk/foo/node_modules/typescript/package.json' exists according to earlier cached lookups.
======== Resolving module '@typescript/lib-webworker/importscripts' from '/home/user/desk/foo/__lib_node_modules_lookup_lib.webworker.importscripts.d.ts__.ts'. ========
Explicitly specified module resolution kind: 'Node10'.
Loading module '@typescript/lib-webworker/importscripts' from 'node_modules' folder, target file types: TypeScript, Declaration.
Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.
Directory '/home/user/desk/foo/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-webworker/importscripts'
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-webworker/importscripts'
Directory '/home/user/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-webworker/importscripts'
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-webworker/importscripts'
Directory '/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-webworker/importscripts'
Loading module '@typescript/lib-webworker/importscripts' from 'node_modules' folder, target file types: JavaScript.
Searching all ancestor node_modules directories for fallback extensions: JavaScript.
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Directory '/node_modules' does not exist, skipping all lookups in it.
======== Module name '@typescript/lib-webworker/importscripts' was not resolved. ========
File '/home/user/desk/foo/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/home/user/desk/foo/node_modules/typescript/package.json' exists according to earlier cached lookups.
======== Resolving module '@typescript/lib-scripthost' from '/home/user/desk/foo/__lib_node_modules_lookup_lib.scripthost.d.ts__.ts'. ========
Explicitly specified module resolution kind: 'Node10'.
Loading module '@typescript/lib-scripthost' from 'node_modules' folder, target file types: TypeScript, Declaration.
Searching all ancestor node_modules directories for preferred extensions: TypeScript, Declaration.
Directory '/home/user/desk/foo/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-scripthost'
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-scripthost'
Directory '/home/user/node_modules/@types' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-scripthost'
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-scripthost'
Directory '/node_modules' does not exist, skipping all lookups in it.
Scoped package detected, looking in 'typescript__lib-scripthost'
Loading module '@typescript/lib-scripthost' from 'node_modules' folder, target file types: JavaScript.
Searching all ancestor node_modules directories for fallback extensions: JavaScript.
Directory '/home/user/desk/node_modules' does not exist, skipping all lookups in it.
Directory '/home/node_modules' does not exist, skipping all lookups in it.
Directory '/node_modules' does not exist, skipping all lookups in it.
======== Module name '@typescript/lib-scripthost' was not resolved. ========
File '/home/user/desk/foo/node_modules/typescript/lib/package.json' does not exist according to earlier cached lookups.
File '/home/user/desk/foo/node_modules/typescript/package.json' exists according to earlier cached lookups.
index.ts:4:14 - error TS2322: Type '{ name: string; type: string; }' is not assignable to type 'Schema'.
Types of property 'type' are incompatible.
Type 'string' is not assignable to type '"File" | "Folder"'.

4 export const schema: Schema = schemaJSON
~~~~~~
```

Found 1 error in index.ts:4

### Paste the `package.json` of the *importing* module, if it exists
```json
{
"name": "foo",
"version": "0.0.0",
"main": "index.js",
"scripts": {
"test": "npx tsc"
},
"keywords": [],
"author": "Stephen Niedzielski (https://oidoid.com/)",
"license": "AGPL-3.0-only",
"description": "",
"devDependencies": {
"typescript": "5.9.3"
}
}
```

### Paste the `package.json` of the *target* module, if it exists

Same as importing module.

### Any other comments can go here

Overriding JSON typing is an important feature for custom schemas. The workarounds now are:

1. Cast.
2. Use a non-JSON extension. For example, `*.jsonc` works.
3. Disable `resolveJsonModule`.
4. Instead of a wildcard, hardcode the module declarations to specific files.

Start with the linked demo repository, then run the supplied tsc configuration and resolution trace to compare the ambient schema-decl.d.ts typing with resolveJsonModule behavior for index.ts. Done means the ambient wildcard declaration's Schema type is honored for the imported JSON while module resolution still finds the right file.

Written by the indexing model from the issue text.