Do not require import attributes for JSON imports in --module node16

src/compiler/checker.ts

@@ -48100,7 +48100,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     }
                 }
 
-                if (isOnlyImportableAsDefault(node.moduleSpecifier, resolvedModule) && !hasTypeJsonImportAttribute(node)) {
+                if (moduleKind === ModuleKind.NodeNext && isOnlyImportableAsDefault(node.moduleSpecifier, resolvedModule) && !hasTypeJsonImportAttribute(node)) {
+                    // Import attributes/assertions are not allowed in --module node16, so don't suggest adding one
                     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]);
                 }
             }

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

@@ -0,0 +1,81 @@
+/loosey.cts(1,36): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+/loosey.cts(6,9): error TS2339: Property 'default' does not exist on type '{ version: number; }'.
+/main.mts(5,36): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+/main.mts(6,52): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+/main.mts(8,10): error TS1544: Named imports from a JSON file into an ECMAScript module are not allowed when 'module' is set to 'Node16'.
+/main.mts(8,41): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+/main.mts(9,42): error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+/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 (6 errors) ====
+    import { oops } from "not.json"; // Ok
+    import moreOops from "actually-json"; // Error in nodenext
+    import typed from "actually-json/typed"; // Error in nodenext
+
+    import config from "./config.json" with { type: "json" }; // Ok
+                                       ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    import { default as config1 } from "./config.json" with { type: "json" }; // Ok
+                                                       ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    import config2 from "./config.json"; // Error in nodenext, no attribute
+    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 'Node16'.
+                                            ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    import * as config3 from "./config.json" with { type: "json" };
+                                             ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    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 TS2823: Import attributes are only supported when the '--module' option is set to 'esnext', 'nodenext', or 'preserve'.
+    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 → tests/baselines/reference/nodeModulesJson(module=node16).symbols

@@ -26,10 +26,10 @@ export default _default;
 import { oops } from "not.json"; // Ok
 >oops : Symbol(oops, Decl(main.mts, 0, 8))
 
-import moreOops from "actually-json"; // Error
+import moreOops from "actually-json"; // Error in nodenext
 >moreOops : Symbol(moreOops, Decl(main.mts, 1, 6))
 
-import typed from "actually-json/typed"; // Error
+import typed from "actually-json/typed"; // Error in nodenext
 >typed : Symbol(typed, Decl(main.mts, 2, 6))
 
 import config from "./config.json" with { type: "json" }; // Ok
@@ -39,7 +39,7 @@ 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
+import config2 from "./config.json"; // Error in nodenext, no attribute
 >config2 : Symbol(config2, Decl(main.mts, 6, 6))
 
 import { version } from "./config.json" with { type: "json" }; // Error, named import

tests/baselines/reference/nodeModulesJson.types → tests/baselines/reference/nodeModulesJson(module=node16).types

@@ -38,11 +38,11 @@ import { oops } from "not.json"; // Ok
 >oops : (json: string) => any
 >     : ^    ^^      ^^^^^   
 
-import moreOops from "actually-json"; // Error
+import moreOops from "actually-json"; // Error in nodenext
 >moreOops : {}
 >         : ^^
 
-import typed from "actually-json/typed"; // Error
+import typed from "actually-json/typed"; // Error in nodenext
 >typed : typeof typed
 >      : ^^^^^^^^^^^^
 
@@ -60,7 +60,7 @@ import { default as config1 } from "./config.json" with { type: "json" }; // Ok
 >type : any
 >     : ^^^
 
-import config2 from "./config.json"; // Error, no attribute
+import config2 from "./config.json"; // Error in nodenext, no attribute
 >config2 : { version: number; }
 >        : ^^^^^^^^^^^^^^^^^^^^
 

tests/baselines/reference/nodeModulesJson.errors.txt → tests/baselines/reference/nodeModulesJson(module=nodenext).errors.txt

@@ -43,16 +43,16 @@
 
 ==== /main.mts (5 errors) ====
     import { oops } from "not.json"; // Ok
-    import moreOops from "actually-json"; // Error
+    import moreOops from "actually-json"; // Error in nodenext
                          ~~~~~~~~~~~~~~~
 !!! 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
+    import typed from "actually-json/typed"; // Error in nodenext
                       ~~~~~~~~~~~~~~~~~~~~~
 !!! 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
+    import config2 from "./config.json"; // Error in nodenext, 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

tests/baselines/reference/nodeModulesJson(module=nodenext).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 in nodenext
+>moreOops : Symbol(moreOops, Decl(main.mts, 1, 6))
+
+import typed from "actually-json/typed"; // Error in nodenext
+>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 in nodenext, 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(module=nodenext).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 in nodenext
+>moreOops : {}
+>         : ^^
+
+import typed from "actually-json/typed"; // Error in nodenext
+>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 in nodenext, 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/cases/conformance/node/nodeModulesJson.ts

@@ -1,4 +1,4 @@
-// @module: nodenext
+// @module: node16,nodenext
 // @resolveJsonModule: true
 // @noEmit: true
 
@@ -38,12 +38,12 @@ export default _default;
 
 // @Filename: /main.mts
 import { oops } from "not.json"; // Ok
-import moreOops from "actually-json"; // Error
-import typed from "actually-json/typed"; // Error
+import moreOops from "actually-json"; // Error in nodenext
+import typed from "actually-json/typed"; // Error in 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
+import config2 from "./config.json"; // Error in nodenext, 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