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;