Validate JSON imports into ESM in --module nodenext (#60019)

src/compiler/checker.ts

@@ -163,7 +163,6 @@ import {
     EmitResolver,
     EmitTextWriter,
     emptyArray,
-    endsWith,
     EntityName,
     EntityNameExpression,
     EntityNameOrEntityNameExpression,
@@ -265,6 +264,7 @@ import {
     getContainingClassStaticBlock,
     getContainingFunction,
     getContainingFunctionOrClassStaticBlock,
+    getDeclarationFileExtension,
     getDeclarationModifierFlagsFromSymbol,
     getDeclarationOfKind,
     getDeclarationsOfKind,
@@ -3702,11 +3702,15 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         return usageMode === ModuleKind.ESNext && targetMode === ModuleKind.CommonJS;
     }
 
-    function isOnlyImportableAsDefault(usage: Expression) {
+    function isOnlyImportableAsDefault(usage: Expression, resolvedModule?: Symbol) {
         // In Node.js, JSON modules don't get named exports
         if (ModuleKind.Node16 <= moduleKind && moduleKind <= ModuleKind.NodeNext) {
             const usageMode = getEmitSyntaxForModuleSpecifierExpression(usage);
-            return usageMode === ModuleKind.ESNext && endsWith((usage as StringLiteralLike).text, Extension.Json);
+            if (usageMode === ModuleKind.ESNext) {
+                resolvedModule ??= resolveExternalModuleName(usage, usage, /*ignoreErrors*/ true);
+                const targetFile = resolvedModule && getSourceFileOfModule(resolvedModule);
+                return targetFile && (isJsonSourceFile(targetFile) || getDeclarationFileExtension(targetFile.fileName) === ".d.json.ts");
+            }
         }
         return false;
     }
@@ -3776,7 +3780,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         if (!specifier) {
             return exportDefaultSymbol;
         }
-        const hasDefaultOnly = isOnlyImportableAsDefault(specifier);
+        const hasDefaultOnly = isOnlyImportableAsDefault(specifier, moduleSymbol);
         const hasSyntheticDefault = canHaveSyntheticDefault(file, moduleSymbol, dontResolveAlias, specifier);
         if (!exportDefaultSymbol && !hasSyntheticDefault && !hasDefaultOnly) {
             if (hasExportAssignmentSymbol(moduleSymbol) && !allowSyntheticDefaultImports) {
@@ -3961,7 +3965,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 let symbolFromModule = getExportOfModule(targetSymbol, nameText, specifier, dontResolveAlias);
                 if (symbolFromModule === undefined && nameText === InternalSymbolName.Default) {
                     const file = moduleSymbol.declarations?.find(isSourceFile);
-                    if (isOnlyImportableAsDefault(moduleSpecifier) || canHaveSyntheticDefault(file, moduleSymbol, dontResolveAlias, moduleSpecifier)) {
+                    if (isOnlyImportableAsDefault(moduleSpecifier, moduleSymbol) || canHaveSyntheticDefault(file, moduleSymbol, dontResolveAlias, moduleSpecifier)) {
                         symbolFromModule = resolveExternalModuleSymbol(moduleSymbol, dontResolveAlias) || resolveSymbol(moduleSymbol, dontResolveAlias);
                     }
                 }
@@ -3969,7 +3973,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 const symbol = symbolFromModule && symbolFromVariable && symbolFromModule !== symbolFromVariable ?
                     combineValueAndTypeSymbols(symbolFromVariable, symbolFromModule) :
                     symbolFromModule || symbolFromVariable;
-                if (!symbol) {
+
+                if (isImportOrExportSpecifier(specifier) && isOnlyImportableAsDefault(moduleSpecifier, moduleSymbol) && nameText !== InternalSymbolName.Default) {
+                    error(name, Diagnostics.Named_imports_from_a_JSON_file_into_an_ECMAScript_module_are_not_allowed_when_module_is_set_to_0, ModuleKind[moduleKind]);
+                }
+                else if (!symbol) {
                     errorNoModuleMemberSymbol(moduleSymbol, targetSymbol, node, name);
                 }
                 return symbol;
@@ -47779,6 +47787,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             grammarErrorOnFirstToken(node, Diagnostics.An_import_declaration_cannot_have_modifiers);
         }
         if (checkExternalImportOrExportDeclaration(node)) {
+            let resolvedModule;
             const importClause = node.importClause;
             if (importClause && !checkGrammarImportClause(importClause)) {
                 if (importClause.name) {
@@ -47793,12 +47802,16 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                         }
                     }
                     else {
-                        const moduleExisted = resolveExternalModuleName(node, node.moduleSpecifier);
-                        if (moduleExisted) {
+                        resolvedModule = resolveExternalModuleName(node, node.moduleSpecifier);
+                        if (resolvedModule) {
                             forEach(importClause.namedBindings.elements, checkImportBinding);
                         }
                     }
                 }
+
+                if (isOnlyImportableAsDefault(node.moduleSpecifier, resolvedModule) && !hasTypeJsonImportAttribute(node)) {
+                    error(node.moduleSpecifier, Diagnostics.Importing_a_JSON_file_into_an_ECMAScript_module_requires_a_type_Colon_json_import_attribute_when_module_is_set_to_0, ModuleKind[moduleKind]);
+                }
             }
             else if (noUncheckedSideEffectImports && !importClause) {
                 void resolveExternalModuleName(node, node.moduleSpecifier);
@@ -47807,6 +47820,10 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         checkImportAttributes(node);
     }
 
+    function hasTypeJsonImportAttribute(node: ImportDeclaration) {
+        return !!node.attributes && node.attributes.elements.some(attr => getTextOfIdentifierOrLiteral(attr.name) === "type" && tryCast(attr.value, isStringLiteralLike)?.text === "json");
+    }
+
     function checkImportEqualsDeclaration(node: ImportEqualsDeclaration) {
         if (checkGrammarModuleElementContext(node, isInJSFile(node) ? Diagnostics.An_import_declaration_can_only_be_used_at_the_top_level_of_a_module : Diagnostics.An_import_declaration_can_only_be_used_at_the_top_level_of_a_namespace_or_module)) {
             // If we hit an import declaration in an illegal context, just bail out to avoid cascading errors.

src/compiler/diagnosticMessages.json

@@ -1826,6 +1826,14 @@
         "category": "Error",
         "code": 1542
     },
+    "Importing a JSON file into an ECMAScript module requires a 'type: \"json\"' import attribute when 'module' is set to '{0}'.": {
+        "category": "Error",
+        "code": 1543
+    },
+    "Named imports from a JSON file into an ECMAScript module are not allowed when 'module' is set to '{0}'.": {
+        "category": "Error",
+        "code": 1544
+    },
 
     "The types of '{0}' are incompatible between these types.": {
         "category": "Error",

src/compiler/parser.ts

@@ -10517,9 +10517,10 @@ export function getDeclarationFileExtension(fileName: string): string | undefine
         return standardExtension;
     }
     if (fileExtensionIs(fileName, Extension.Ts)) {
-        const index = getBaseFileName(fileName).lastIndexOf(".d.");
+        const baseName = getBaseFileName(fileName);
+        const index = baseName.lastIndexOf(".d.");
         if (index >= 0) {
-            return fileName.substring(index);
+            return baseName.substring(index);
         }
     }
     return undefined;

tests/baselines/reference/nodeModulesJson.errors.txt

@@ -0,0 +1,78 @@
+/loosey.cts(1,36): error TS2856: Import attributes are not allowed on statements that compile to CommonJS 'require' calls.
+/loosey.cts(6,9): error TS2339: Property 'default' does not exist on type '{ version: number; }'.
+/main.mts(2,22): error TS1543: Importing a JSON file into an ECMAScript module requires a 'type: "json"' import attribute when 'module' is set to 'NodeNext'.
+/main.mts(3,19): error TS1543: Importing a JSON file into an ECMAScript module requires a 'type: "json"' import attribute when 'module' is set to 'NodeNext'.
+/main.mts(7,21): error TS1543: Importing a JSON file into an ECMAScript module requires a 'type: "json"' import attribute when 'module' is set to 'NodeNext'.
+/main.mts(8,10): error TS1544: Named imports from a JSON file into an ECMAScript module are not allowed when 'module' is set to 'NodeNext'.
+/main.mts(10,9): error TS2339: Property 'version' does not exist on type '{ default: { version: number; }; }'.
+
+
+==== /node_modules/not.json/package.json (0 errors) ====
+    {
+      "name": "not.json",
+      "version": "1.0.0",
+      "type": "module",
+      "exports": "./index.js"
+    }
+    
+==== /node_modules/not.json/index.d.ts (0 errors) ====
+    export function oops(json: string): any;
+    
+==== /node_modules/actually-json/package.json (0 errors) ====
+    {
+      "name": "actually-json",
+      "version": "1.0.0",
+      "type": "module",
+      "exports": {
+        ".": "./index.json",
+        "./typed": "./typed.d.json.ts"
+      }
+    }
+    
+==== /node_modules/actually-json/index.json (0 errors) ====
+    {}
+    
+==== /node_modules/actually-json/typed.d.json.ts (0 errors) ====
+    declare const _default: {};
+    export default _default;
+    
+==== /config.json (0 errors) ====
+    {
+      "version": 1
+    }
+    
+==== /main.mts (5 errors) ====
+    import { oops } from "not.json"; // Ok
+    import moreOops from "actually-json"; // Error
+                         ~~~~~~~~~~~~~~~
+!!! error TS1543: Importing a JSON file into an ECMAScript module requires a 'type: "json"' import attribute when 'module' is set to 'NodeNext'.
+    import typed from "actually-json/typed"; // Error
+                      ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1543: Importing a JSON file into an ECMAScript module requires a 'type: "json"' import attribute when 'module' is set to 'NodeNext'.
+    
+    import config from "./config.json" with { type: "json" }; // Ok
+    import { default as config1 } from "./config.json" with { type: "json" }; // Ok
+    import config2 from "./config.json"; // Error, no attribute
+                        ~~~~~~~~~~~~~~~
+!!! error TS1543: Importing a JSON file into an ECMAScript module requires a 'type: "json"' import attribute when 'module' is set to 'NodeNext'.
+    import { version } from "./config.json" with { type: "json" }; // Error, named import
+             ~~~~~~~
+!!! error TS1544: Named imports from a JSON file into an ECMAScript module are not allowed when 'module' is set to 'NodeNext'.
+    import * as config3 from "./config.json" with { type: "json" };
+    config3.version; // Error
+            ~~~~~~~
+!!! error TS2339: Property 'version' does not exist on type '{ default: { version: number; }; }'.
+    config3.default; // Ok
+    
+==== /loosey.cts (2 errors) ====
+    import config from "./config.json" with { type: "json" }; // Error
+                                       ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2856: Import attributes are not allowed on statements that compile to CommonJS 'require' calls.
+    import config2 from "./config.json"; // Ok
+    import { version } from "./config.json"; // Ok
+    import * as config3 from "./config.json";
+    config3.version; // Ok
+    config3.default; // Error
+            ~~~~~~~
+!!! error TS2339: Property 'default' does not exist on type '{ version: number; }'.
+    

tests/baselines/reference/nodeModulesJson.symbols

@@ -0,0 +1,79 @@
+//// [tests/cases/conformance/node/nodeModulesJson.ts] ////
+
+=== /node_modules/not.json/index.d.ts ===
+export function oops(json: string): any;
+>oops : Symbol(oops, Decl(index.d.ts, 0, 0))
+>json : Symbol(json, Decl(index.d.ts, 0, 21))
+
+=== /node_modules/actually-json/index.json ===
+
+{}
+
+=== /node_modules/actually-json/typed.d.json.ts ===
+declare const _default: {};
+>_default : Symbol(_default, Decl(typed.d.json.ts, 0, 13))
+
+export default _default;
+>_default : Symbol(_default, Decl(typed.d.json.ts, 0, 13))
+
+=== /config.json ===
+{
+  "version": 1
+>"version" : Symbol("version", Decl(config.json, 0, 1))
+}
+
+=== /main.mts ===
+import { oops } from "not.json"; // Ok
+>oops : Symbol(oops, Decl(main.mts, 0, 8))
+
+import moreOops from "actually-json"; // Error
+>moreOops : Symbol(moreOops, Decl(main.mts, 1, 6))
+
+import typed from "actually-json/typed"; // Error
+>typed : Symbol(typed, Decl(main.mts, 2, 6))
+
+import config from "./config.json" with { type: "json" }; // Ok
+>config : Symbol(config, Decl(main.mts, 4, 6))
+
+import { default as config1 } from "./config.json" with { type: "json" }; // Ok
+>default : Symbol(config, Decl(config.json, 0, 0))
+>config1 : Symbol(config1, Decl(main.mts, 5, 8))
+
+import config2 from "./config.json"; // Error, no attribute
+>config2 : Symbol(config2, Decl(main.mts, 6, 6))
+
+import { version } from "./config.json" with { type: "json" }; // Error, named import
+>version : Symbol(version, Decl(main.mts, 7, 8))
+
+import * as config3 from "./config.json" with { type: "json" };
+>config3 : Symbol(config3, Decl(main.mts, 8, 6))
+
+config3.version; // Error
+>config3 : Symbol(config3, Decl(main.mts, 8, 6))
+
+config3.default; // Ok
+>config3.default : Symbol("/config")
+>config3 : Symbol(config3, Decl(main.mts, 8, 6))
+>default : Symbol("/config")
+
+=== /loosey.cts ===
+import config from "./config.json" with { type: "json" }; // Error
+>config : Symbol(config, Decl(loosey.cts, 0, 6))
+
+import config2 from "./config.json"; // Ok
+>config2 : Symbol(config2, Decl(loosey.cts, 1, 6))
+
+import { version } from "./config.json"; // Ok
+>version : Symbol(version, Decl(loosey.cts, 2, 8))
+
+import * as config3 from "./config.json";
+>config3 : Symbol(config3, Decl(loosey.cts, 3, 6))
+
+config3.version; // Ok
+>config3.version : Symbol(version, Decl(config.json, 0, 1))
+>config3 : Symbol(config3, Decl(loosey.cts, 3, 6))
+>version : Symbol(version, Decl(config.json, 0, 1))
+
+config3.default; // Error
+>config3 : Symbol(config3, Decl(loosey.cts, 3, 6))
+

tests/baselines/reference/nodeModulesJson.types

@@ -0,0 +1,129 @@
+//// [tests/cases/conformance/node/nodeModulesJson.ts] ////
+
+=== /node_modules/not.json/index.d.ts ===
+export function oops(json: string): any;
+>oops : (json: string) => any
+>     : ^    ^^      ^^^^^   
+>json : string
+>     : ^^^^^^
+
+=== /node_modules/actually-json/index.json ===
+{}
+>{} : {}
+>   : ^^
+
+=== /node_modules/actually-json/typed.d.json.ts ===
+declare const _default: {};
+>_default : {}
+>         : ^^
+
+export default _default;
+>_default : {}
+>         : ^^
+
+=== /config.json ===
+{
+>{  "version": 1} : { version: number; }
+>                 : ^^^^^^^^^^^^^^^^^^^^
+
+  "version": 1
+>"version" : number
+>          : ^^^^^^
+>1 : 1
+>  : ^
+}
+
+=== /main.mts ===
+import { oops } from "not.json"; // Ok
+>oops : (json: string) => any
+>     : ^    ^^      ^^^^^   
+
+import moreOops from "actually-json"; // Error
+>moreOops : {}
+>         : ^^
+
+import typed from "actually-json/typed"; // Error
+>typed : typeof typed
+>      : ^^^^^^^^^^^^
+
+import config from "./config.json" with { type: "json" }; // Ok
+>config : { version: number; }
+>       : ^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
+
+import { default as config1 } from "./config.json" with { type: "json" }; // Ok
+>default : { version: number; }
+>        : ^^^^^^^^^^^^^^^^^^^^
+>config1 : { version: number; }
+>        : ^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
+
+import config2 from "./config.json"; // Error, no attribute
+>config2 : { version: number; }
+>        : ^^^^^^^^^^^^^^^^^^^^
+
+import { version } from "./config.json" with { type: "json" }; // Error, named import
+>version : number
+>        : ^^^^^^
+>type : any
+>     : ^^^
+
+import * as config3 from "./config.json" with { type: "json" };
+>config3 : { default: { version: number; }; }
+>        : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
+
+config3.version; // Error
+>config3.version : any
+>                : ^^^
+>config3 : { default: { version: number; }; }
+>        : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>version : any
+>        : ^^^
+
+config3.default; // Ok
+>config3.default : { version: number; }
+>                : ^^^^^^^^^^^^^^^^^^^^
+>config3 : { default: { version: number; }; }
+>        : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>default : { version: number; }
+>        : ^^^^^^^^^^^^^^^^^^^^
+
+=== /loosey.cts ===
+import config from "./config.json" with { type: "json" }; // Error
+>config : { version: number; }
+>       : ^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
+
+import config2 from "./config.json"; // Ok
+>config2 : { version: number; }
+>        : ^^^^^^^^^^^^^^^^^^^^
+
+import { version } from "./config.json"; // Ok
+>version : number
+>        : ^^^^^^
+
+import * as config3 from "./config.json";
+>config3 : { version: number; }
+>        : ^^^^^^^^^^^^^^^^^^^^
+
+config3.version; // Ok
+>config3.version : number
+>                : ^^^^^^
+>config3 : { version: number; }
+>        : ^^^^^^^^^^^^^^^^^^^^
+>version : number
+>        : ^^^^^^
+
+config3.default; // Error
+>config3.default : any
+>                : ^^^
+>config3 : { version: number; }
+>        : ^^^^^^^^^^^^^^^^^^^^
+>default : any
+>        : ^^^
+

tests/baselines/reference/nodeModulesResolveJsonModule(module=node16).errors.txt

@@ -0,0 +1,39 @@
+index.mts(1,34): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+index.mts(3,38): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+index.ts(1,34): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+index.ts(3,38): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+
+
+==== index.ts (2 errors) ====
+    import pkg from "./package.json" with { type: "json" };
+                                     ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    export const name = pkg.name;
+    import * as ns from "./package.json" with { type: "json" };
+                                         ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    export const thing = ns;
+    export const name2 = ns.default.name;
+==== index.cts (0 errors) ====
+    import pkg from "./package.json";
+    export const name = pkg.name;
+    import * as ns from "./package.json";
+    export const thing = ns;
+    export const name2 = ns.default.name;
+==== index.mts (2 errors) ====
+    import pkg from "./package.json" with { type: "json" };
+                                     ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    export const name = pkg.name;
+    import * as ns from "./package.json" with { type: "json" };
+                                         ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    export const thing = ns;
+    export const name2 = ns.default.name;
+==== package.json (0 errors) ====
+    {
+        "name": "pkg",
+        "version": "0.0.1",
+        "type": "module",
+        "default": "misedirection"
+    }

tests/baselines/reference/nodeModulesResolveJsonModule(module=node16).js

@@ -1,21 +1,21 @@
 //// [tests/cases/conformance/node/nodeModulesResolveJsonModule.ts] ////
 
 //// [index.ts]
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 //// [index.cts]
-import pkg from "./package.json"
+import pkg from "./package.json";
 export const name = pkg.name;
 import * as ns from "./package.json";
 export const thing = ns;
 export const name2 = ns.default.name;
 //// [index.mts]
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 //// [package.json]
@@ -34,9 +34,9 @@ export const name2 = ns.default.name;
     "default": "misedirection"
 }
 //// [index.js]
-import pkg from "./package.json";
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 //// [index.cjs]
@@ -75,9 +75,9 @@ const ns = __importStar(require("./package.json"));
 exports.thing = ns;
 exports.name2 = ns.default.name;
 //// [index.mjs]
-import pkg from "./package.json";
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 

tests/baselines/reference/nodeModulesResolveJsonModule(module=node16).symbols

@@ -1,7 +1,7 @@
 //// [tests/cases/conformance/node/nodeModulesResolveJsonModule.ts] ////
 
 === index.ts ===
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 >pkg : Symbol(pkg, Decl(index.ts, 0, 6))
 
 export const name = pkg.name;
@@ -10,7 +10,7 @@ export const name = pkg.name;
 >pkg : Symbol(pkg, Decl(index.ts, 0, 6))
 >name : Symbol("name", Decl(package.json, 0, 1))
 
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 >ns : Symbol(ns, Decl(index.ts, 2, 6))
 
 export const thing = ns;
@@ -26,7 +26,7 @@ export const name2 = ns.default.name;
 >name : Symbol("name", Decl(package.json, 0, 1))
 
 === index.cts ===
-import pkg from "./package.json"
+import pkg from "./package.json";
 >pkg : Symbol(pkg, Decl(index.cts, 0, 6))
 
 export const name = pkg.name;
@@ -51,7 +51,7 @@ export const name2 = ns.default.name;
 >name : Symbol("name", Decl(package.json, 0, 1))
 
 === index.mts ===
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 >pkg : Symbol(pkg, Decl(index.mts, 0, 6))
 
 export const name = pkg.name;
@@ -60,7 +60,7 @@ export const name = pkg.name;
 >pkg : Symbol(pkg, Decl(index.mts, 0, 6))
 >name : Symbol("name", Decl(package.json, 0, 1))
 
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 >ns : Symbol(ns, Decl(index.mts, 2, 6))
 
 export const thing = ns;

tests/baselines/reference/nodeModulesResolveJsonModule(module=node16).types

@@ -1,9 +1,11 @@
 //// [tests/cases/conformance/node/nodeModulesResolveJsonModule.ts] ////
 
 === index.ts ===
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 >pkg : { name: string; version: string; type: string; default: string; }
 >    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
 
 export const name = pkg.name;
 >name : string
@@ -15,9 +17,11 @@ export const name = pkg.name;
 >name : string
 >     : ^^^^^^
 
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 >ns : { default: { name: string; version: string; type: string; default: string; }; }
 >   : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
 
 export const thing = ns;
 >thing : { default: { name: string; version: string; type: string; default: string; }; }
@@ -40,7 +44,7 @@ export const name2 = ns.default.name;
 >     : ^^^^^^
 
 === index.cts ===
-import pkg from "./package.json"
+import pkg from "./package.json";
 >pkg : { name: string; version: string; type: string; default: string; }
 >    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -79,9 +83,11 @@ export const name2 = ns.default.name;
 >     : ^^^^^^
 
 === index.mts ===
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 >pkg : { name: string; version: string; type: string; default: string; }
 >    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
 
 export const name = pkg.name;
 >name : string
@@ -93,9 +99,11 @@ export const name = pkg.name;
 >name : string
 >     : ^^^^^^
 
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 >ns : { default: { name: string; version: string; type: string; default: string; }; }
 >   : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : any
+>     : ^^^
 
 export const thing = ns;
 >thing : { default: { name: string; version: string; type: string; default: string; }; }

tests/baselines/reference/nodeModulesResolveJsonModule(module=nodenext).js

@@ -1,21 +1,21 @@
 //// [tests/cases/conformance/node/nodeModulesResolveJsonModule.ts] ////
 
 //// [index.ts]
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 //// [index.cts]
-import pkg from "./package.json"
+import pkg from "./package.json";
 export const name = pkg.name;
 import * as ns from "./package.json";
 export const thing = ns;
 export const name2 = ns.default.name;
 //// [index.mts]
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 //// [package.json]
@@ -34,9 +34,9 @@ export const name2 = ns.default.name;
     "default": "misedirection"
 }
 //// [index.js]
-import pkg from "./package.json";
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 //// [index.cjs]
@@ -75,9 +75,9 @@ const ns = __importStar(require("./package.json"));
 exports.thing = ns;
 exports.name2 = ns.default.name;
 //// [index.mjs]
-import pkg from "./package.json";
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 

tests/baselines/reference/nodeModulesResolveJsonModule(module=nodenext).symbols

@@ -1,7 +1,7 @@
 //// [tests/cases/conformance/node/nodeModulesResolveJsonModule.ts] ////
 
 === index.ts ===
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 >pkg : Symbol(pkg, Decl(index.ts, 0, 6))
 
 export const name = pkg.name;
@@ -10,7 +10,7 @@ export const name = pkg.name;
 >pkg : Symbol(pkg, Decl(index.ts, 0, 6))
 >name : Symbol("name", Decl(package.json, 0, 1))
 
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 >ns : Symbol(ns, Decl(index.ts, 2, 6))
 
 export const thing = ns;
@@ -26,7 +26,7 @@ export const name2 = ns.default.name;
 >name : Symbol("name", Decl(package.json, 0, 1))
 
 === index.cts ===
-import pkg from "./package.json"
+import pkg from "./package.json";
 >pkg : Symbol(pkg, Decl(index.cts, 0, 6))
 
 export const name = pkg.name;
@@ -51,7 +51,7 @@ export const name2 = ns.default.name;
 >name : Symbol("name", Decl(package.json, 0, 1))
 
 === index.mts ===
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 >pkg : Symbol(pkg, Decl(index.mts, 0, 6))
 
 export const name = pkg.name;
@@ -60,7 +60,7 @@ export const name = pkg.name;
 >pkg : Symbol(pkg, Decl(index.mts, 0, 6))
 >name : Symbol("name", Decl(package.json, 0, 1))
 
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 >ns : Symbol(ns, Decl(index.mts, 2, 6))
 
 export const thing = ns;

tests/baselines/reference/nodeModulesResolveJsonModule(module=nodenext).types

@@ -1,9 +1,10 @@
 //// [tests/cases/conformance/node/nodeModulesResolveJsonModule.ts] ////
 
 === index.ts ===
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 >pkg : { name: string; version: string; type: string; default: string; }
 >    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : error
 
 export const name = pkg.name;
 >name : string
@@ -15,9 +16,10 @@ export const name = pkg.name;
 >name : string
 >     : ^^^^^^
 
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 >ns : { default: { name: string; version: string; type: string; default: string; }; }
 >   : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : error
 
 export const thing = ns;
 >thing : { default: { name: string; version: string; type: string; default: string; }; }
@@ -40,7 +42,7 @@ export const name2 = ns.default.name;
 >     : ^^^^^^
 
 === index.cts ===
-import pkg from "./package.json"
+import pkg from "./package.json";
 >pkg : { name: string; version: string; type: string; default: string; }
 >    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -79,9 +81,10 @@ export const name2 = ns.default.name;
 >     : ^^^^^^
 
 === index.mts ===
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 >pkg : { name: string; version: string; type: string; default: string; }
 >    : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : error
 
 export const name = pkg.name;
 >name : string
@@ -93,9 +96,10 @@ export const name = pkg.name;
 >name : string
 >     : ^^^^^^
 
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 >ns : { default: { name: string; version: string; type: string; default: string; }; }
 >   : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+>type : error
 
 export const thing = ns;
 >thing : { default: { name: string; version: string; type: string; default: string; }; }

tests/cases/conformance/node/nodeModulesJson.ts

@@ -0,0 +1,58 @@
+// @module: nodenext
+// @resolveJsonModule: true
+// @noEmit: true
+
+// @Filename: /node_modules/not.json/package.json
+{
+  "name": "not.json",
+  "version": "1.0.0",
+  "type": "module",
+  "exports": "./index.js"
+}
+
+// @Filename: /node_modules/not.json/index.d.ts
+export function oops(json: string): any;
+
+// @Filename: /node_modules/actually-json/package.json
+{
+  "name": "actually-json",
+  "version": "1.0.0",
+  "type": "module",
+  "exports": {
+    ".": "./index.json",
+    "./typed": "./typed.d.json.ts"
+  }
+}
+
+// @Filename: /node_modules/actually-json/index.json
+{}
+
+// @Filename: /node_modules/actually-json/typed.d.json.ts
+declare const _default: {};
+export default _default;
+
+// @Filename: /config.json
+{
+  "version": 1
+}
+
+// @Filename: /main.mts
+import { oops } from "not.json"; // Ok
+import moreOops from "actually-json"; // Error
+import typed from "actually-json/typed"; // Error
+
+import config from "./config.json" with { type: "json" }; // Ok
+import { default as config1 } from "./config.json" with { type: "json" }; // Ok
+import config2 from "./config.json"; // Error, no attribute
+import { version } from "./config.json" with { type: "json" }; // Error, named import
+import * as config3 from "./config.json" with { type: "json" };
+config3.version; // Error
+config3.default; // Ok
+
+// @Filename: /loosey.cts
+import config from "./config.json" with { type: "json" }; // Error
+import config2 from "./config.json"; // Ok
+import { version } from "./config.json"; // Ok
+import * as config3 from "./config.json";
+config3.version; // Ok
+config3.default; // Error

tests/cases/conformance/node/nodeModulesResolveJsonModule.ts

@@ -3,21 +3,21 @@
 // @outDir: ./out
 // @declaration: true
 // @filename: index.ts
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 // @filename: index.cts
-import pkg from "./package.json"
+import pkg from "./package.json";
 export const name = pkg.name;
 import * as ns from "./package.json";
 export const thing = ns;
 export const name2 = ns.default.name;
 // @filename: index.mts
-import pkg from "./package.json"
+import pkg from "./package.json" with { type: "json" };
 export const name = pkg.name;
-import * as ns from "./package.json";
+import * as ns from "./package.json" with { type: "json" };
 export const thing = ns;
 export const name2 = ns.default.name;
 // @filename: package.json