fix(36909): wrong error message when trying to named-import an export

src/compiler/checker.ts

@@ -2538,7 +2538,7 @@ namespace ts {
                                 );
                             }
                             else {
-                                reportNonExportedMember(name, declarationName, moduleSymbol, moduleName);
+                                reportNonExportedMember(node, name, declarationName, moduleSymbol, moduleName);
                             }
                         }
                     }
@@ -2547,27 +2547,50 @@ namespace ts {
             }
         }
 
-        function reportNonExportedMember(name: Identifier, declarationName: string, moduleSymbol: Symbol, moduleName: string): void {
+        function reportNonExportedMember(node: ImportDeclaration | ExportDeclaration, name: Identifier, declarationName: string, moduleSymbol: Symbol, moduleName: string): void {
             const localSymbol = moduleSymbol.valueDeclaration.locals?.get(name.escapedText);
             const exports = moduleSymbol.exports;
-
             if (localSymbol) {
-                const exportedSymbol = exports && !exports.has(InternalSymbolName.ExportEquals)
-                    ? find(symbolsToArray(exports), symbol => !!getSymbolIfSameReference(symbol, localSymbol))
-                    : undefined;
-                const diagnostic = exportedSymbol
-                    ? error(name, Diagnostics.Module_0_declares_1_locally_but_it_is_exported_as_2, moduleName, declarationName, symbolToString(exportedSymbol))
-                    : error(name, Diagnostics.Module_0_declares_1_locally_but_it_is_not_exported, moduleName, declarationName);
+                const exportedEqualsSymbol = exports?.get(InternalSymbolName.ExportEquals);
+                if (exportedEqualsSymbol) {
+                    getSymbolIfSameReference(exportedEqualsSymbol, localSymbol) ? reportInvalidImportEqualsExportMember(node, name, declarationName, moduleName) :
+                        error(name, Diagnostics.Module_0_has_no_exported_member_1, moduleName, declarationName);
+                }
+                else {
+                    const exportedSymbol = exports ? find(symbolsToArray(exports), symbol => !!getSymbolIfSameReference(symbol, localSymbol)) : undefined;
+                    const diagnostic = exportedSymbol ? error(name, Diagnostics.Module_0_declares_1_locally_but_it_is_exported_as_2, moduleName, declarationName, symbolToString(exportedSymbol)) :
+                        error(name, Diagnostics.Module_0_declares_1_locally_but_it_is_not_exported, moduleName, declarationName);
 
-                addRelatedInfo(diagnostic,
-                    ...map(localSymbol.declarations, (decl, index) =>
-                        createDiagnosticForNode(decl, index === 0 ? Diagnostics._0_is_declared_here : Diagnostics.and_here, declarationName)));
+                    addRelatedInfo(diagnostic,
+                        ...map(localSymbol.declarations, (decl, index) =>
+                            createDiagnosticForNode(decl, index === 0 ? Diagnostics._0_is_declared_here : Diagnostics.and_here, declarationName)));
+                }
             }
             else {
                 error(name, Diagnostics.Module_0_has_no_exported_member_1, moduleName, declarationName);
             }
         }
 
+        function reportInvalidImportEqualsExportMember(node: ImportDeclaration | ExportDeclaration, name: Identifier, declarationName: string, moduleName: string) {
+            if (moduleKind >= ModuleKind.ES2015) {
+                const message = compilerOptions.esModuleInterop ? Diagnostics._0_can_only_be_imported_by_using_a_default_import :
+                    Diagnostics._0_can_only_be_imported_by_turning_on_the_esModuleInterop_flag_and_using_a_default_import;
+                error(name, message, declarationName);
+            }
+            else {
+                if (isInJSFile(node)) {
+                    const message = compilerOptions.esModuleInterop ? Diagnostics._0_can_only_be_imported_by_using_a_require_call_or_by_using_a_default_import :
+                        Diagnostics._0_can_only_be_imported_by_using_a_require_call_or_by_turning_on_the_esModuleInterop_flag_and_using_a_default_import;
+                    error(name, message, declarationName);
+                }
+                else {
+                    const message = compilerOptions.esModuleInterop ? Diagnostics._0_can_only_be_imported_by_using_import_1_require_2_or_a_default_import :
+                        Diagnostics._0_can_only_be_imported_by_using_import_1_require_2_or_by_turning_on_the_esModuleInterop_flag_and_using_a_default_import;
+                    error(name, message, declarationName, declarationName, moduleName);
+                }
+            }
+        }
+
         function getTargetOfImportSpecifier(node: ImportSpecifier, dontResolveAlias: boolean): Symbol | undefined {
             const resolved = getExternalModuleMember(node.parent.parent.parent, node, dontResolveAlias);
             markSymbolOfAliasDeclarationIfTypeOnly(node, /*immediateTarget*/ undefined, resolved, /*overwriteEmpty*/ false);

src/compiler/diagnosticMessages.json

@@ -2317,6 +2317,22 @@
         "category": "Error",
         "code": 2594
     },
+    "'{0}' can only be imported by using a default import.": {
+        "category": "Error",
+        "code": 2595
+    },
+    "'{0}' can only be imported by turning on the 'esModuleInterop' flag and using a default import.": {
+        "category": "Error",
+        "code": 2596
+    },
+    "'{0}' can only be imported by using a 'require' call or by using a default import.": {
+        "category": "Error",
+        "code": 2597
+    },
+    "'{0}' can only be imported by using a 'require' call or by turning on the 'esModuleInterop' flag and using a default import.": {
+        "category": "Error",
+        "code": 2598
+    },
     "JSX element attributes type '{0}' may not be a union type.": {
         "category": "Error",
         "code": 2600
@@ -2381,6 +2397,14 @@
         "category": "Error",
         "code": 2615
     },
+    "'{0}' can only be imported by using 'import {1} = require({2})' or a default import.": {
+        "category": "Error",
+        "code": 2616
+    },
+    "'{0}' can only be imported by using 'import {1} = require({2})' or by turning on the 'esModuleInterop' flag and using a default import.": {
+        "category": "Error",
+        "code": 2617
+    },
 
     "Cannot augment module '{0}' with value exports because it resolves to a non-module entity.": {
         "category": "Error",

tests/baselines/reference/es6ImportNamedImportNoNamedExports.errors.txt

@@ -1,5 +1,5 @@
-tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(1,10): error TS2459: Module '"./es6ImportNamedImportNoNamedExports_0"' declares 'a' locally, but it is not exported.
-tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(2,10): error TS2459: Module '"./es6ImportNamedImportNoNamedExports_0"' declares 'a' locally, but it is not exported.
+tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(1,10): error TS2617: 'a' can only be imported by using 'import a = require("./es6ImportNamedImportNoNamedExports_0")' or by turning on the 'esModuleInterop' flag and using a default import.
+tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(2,10): error TS2617: 'a' can only be imported by using 'import a = require("./es6ImportNamedImportNoNamedExports_0")' or by turning on the 'esModuleInterop' flag and using a default import.
 
 
 ==== tests/cases/compiler/es6ImportNamedImportNoNamedExports_0.ts (0 errors) ====
@@ -9,9 +9,7 @@ tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(2,10): error TS2459
 ==== tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts (2 errors) ====
     import { a } from "./es6ImportNamedImportNoNamedExports_0";
              ~
-!!! error TS2459: Module '"./es6ImportNamedImportNoNamedExports_0"' declares 'a' locally, but it is not exported.
-!!! related TS2728 tests/cases/compiler/es6ImportNamedImportNoNamedExports_0.ts:1:5: 'a' is declared here.
+!!! error TS2617: 'a' can only be imported by using 'import a = require("./es6ImportNamedImportNoNamedExports_0")' or by turning on the 'esModuleInterop' flag and using a default import.
     import { a as x } from "./es6ImportNamedImportNoNamedExports_0";
              ~
-!!! error TS2459: Module '"./es6ImportNamedImportNoNamedExports_0"' declares 'a' locally, but it is not exported.
-!!! related TS2728 tests/cases/compiler/es6ImportNamedImportNoNamedExports_0.ts:1:5: 'a' is declared here.
+!!! error TS2617: 'a' can only be imported by using 'import a = require("./es6ImportNamedImportNoNamedExports_0")' or by turning on the 'esModuleInterop' flag and using a default import.

tests/baselines/reference/importNonExportedMember10.errors.txt

@@ -0,0 +1,17 @@
+tests/cases/compiler/a.ts(2,1): error TS1203: Export assignment cannot be used when targeting ECMAScript modules. Consider using 'export default' or another module format instead.
+tests/cases/compiler/b.js(1,10): error TS2596: 'Foo' can only be imported by turning on the 'esModuleInterop' flag and using a default import.
+tests/cases/compiler/b.js(1,21): error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'allowSyntheticDefaultImports' flag and referencing its default export.
+
+
+==== tests/cases/compiler/a.ts (1 errors) ====
+    class Foo {}
+    export = Foo;
+    ~~~~~~~~~~~~~
+!!! error TS1203: Export assignment cannot be used when targeting ECMAScript modules. Consider using 'export default' or another module format instead.
+
+==== tests/cases/compiler/b.js (2 errors) ====
+    import { Foo } from './a';
+             ~~~
+!!! error TS2596: 'Foo' can only be imported by turning on the 'esModuleInterop' flag and using a default import.
+                        ~~~~~
+!!! error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'allowSyntheticDefaultImports' flag and referencing its default export.

tests/baselines/reference/importNonExportedMember10.symbols

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+export = Foo;
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+=== tests/cases/compiler/b.js ===
+import { Foo } from './a';
+>Foo : Symbol(Foo, Decl(b.js, 0, 8))
+

tests/baselines/reference/importNonExportedMember10.types

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Foo
+
+export = Foo;
+>Foo : Foo
+
+=== tests/cases/compiler/b.js ===
+import { Foo } from './a';
+>Foo : any
+

tests/baselines/reference/importNonExportedMember11.errors.txt

@@ -0,0 +1,17 @@
+tests/cases/compiler/a.ts(2,1): error TS1203: Export assignment cannot be used when targeting ECMAScript modules. Consider using 'export default' or another module format instead.
+tests/cases/compiler/b.js(1,10): error TS2595: 'Foo' can only be imported by using a default import.
+tests/cases/compiler/b.js(1,21): error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'allowSyntheticDefaultImports' flag and referencing its default export.
+
+
+==== tests/cases/compiler/a.ts (1 errors) ====
+    class Foo {}
+    export = Foo;
+    ~~~~~~~~~~~~~
+!!! error TS1203: Export assignment cannot be used when targeting ECMAScript modules. Consider using 'export default' or another module format instead.
+
+==== tests/cases/compiler/b.js (2 errors) ====
+    import { Foo } from './a';
+             ~~~
+!!! error TS2595: 'Foo' can only be imported by using a default import.
+                        ~~~~~
+!!! error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'allowSyntheticDefaultImports' flag and referencing its default export.

tests/baselines/reference/importNonExportedMember11.symbols

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+export = Foo;
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+=== tests/cases/compiler/b.js ===
+import { Foo } from './a';
+>Foo : Symbol(Foo, Decl(b.js, 0, 8))
+

tests/baselines/reference/importNonExportedMember11.types

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Foo
+
+export = Foo;
+>Foo : Foo
+
+=== tests/cases/compiler/b.js ===
+import { Foo } from './a';
+>Foo : any
+

tests/baselines/reference/importNonExportedMember4.errors.txt

@@ -0,0 +1,14 @@
+tests/cases/compiler/b.ts(1,10): error TS2617: 'Foo' can only be imported by using 'import Foo = require("./a")' or by turning on the 'esModuleInterop' flag and using a default import.
+tests/cases/compiler/b.ts(1,21): error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'esModuleInterop' flag and referencing its default export.
+
+
+==== tests/cases/compiler/a.ts (0 errors) ====
+    class Foo {}
+    export = Foo;
+
+==== tests/cases/compiler/b.ts (2 errors) ====
+    import { Foo } from './a';
+             ~~~
+!!! error TS2617: 'Foo' can only be imported by using 'import Foo = require("./a")' or by turning on the 'esModuleInterop' flag and using a default import.
+                        ~~~~~
+!!! error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'esModuleInterop' flag and referencing its default export.

tests/baselines/reference/importNonExportedMember4.js

@@ -0,0 +1,20 @@
+//// [tests/cases/compiler/importNonExportedMember4.ts] ////
+
+//// [a.ts]
+class Foo {}
+export = Foo;
+
+//// [b.ts]
+import { Foo } from './a';
+
+//// [a.js]
+"use strict";
+var Foo = /** @class */ (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+module.exports = Foo;
+//// [b.js]
+"use strict";
+exports.__esModule = true;

tests/baselines/reference/importNonExportedMember4.symbols

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+export = Foo;
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+=== tests/cases/compiler/b.ts ===
+import { Foo } from './a';
+>Foo : Symbol(Foo, Decl(b.ts, 0, 8))
+

tests/baselines/reference/importNonExportedMember4.types

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Foo
+
+export = Foo;
+>Foo : Foo
+
+=== tests/cases/compiler/b.ts ===
+import { Foo } from './a';
+>Foo : any
+

tests/baselines/reference/importNonExportedMember5.errors.txt

@@ -0,0 +1,14 @@
+tests/cases/compiler/b.ts(1,10): error TS2616: 'Foo' can only be imported by using 'import Foo = require("./a")' or a default import.
+tests/cases/compiler/b.ts(1,21): error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'esModuleInterop' flag and referencing its default export.
+
+
+==== tests/cases/compiler/a.ts (0 errors) ====
+    class Foo {}
+    export = Foo;
+
+==== tests/cases/compiler/b.ts (2 errors) ====
+    import { Foo } from './a';
+             ~~~
+!!! error TS2616: 'Foo' can only be imported by using 'import Foo = require("./a")' or a default import.
+                        ~~~~~
+!!! error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'esModuleInterop' flag and referencing its default export.

tests/baselines/reference/importNonExportedMember5.js

@@ -0,0 +1,20 @@
+//// [tests/cases/compiler/importNonExportedMember5.ts] ////
+
+//// [a.ts]
+class Foo {}
+export = Foo;
+
+//// [b.ts]
+import { Foo } from './a';
+
+//// [a.js]
+"use strict";
+var Foo = /** @class */ (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+module.exports = Foo;
+//// [b.js]
+"use strict";
+exports.__esModule = true;

tests/baselines/reference/importNonExportedMember5.symbols

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+export = Foo;
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+=== tests/cases/compiler/b.ts ===
+import { Foo } from './a';
+>Foo : Symbol(Foo, Decl(b.ts, 0, 8))
+

tests/baselines/reference/importNonExportedMember5.types

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Foo
+
+export = Foo;
+>Foo : Foo
+
+=== tests/cases/compiler/b.ts ===
+import { Foo } from './a';
+>Foo : any
+

tests/baselines/reference/importNonExportedMember6.errors.txt

@@ -0,0 +1,17 @@
+tests/cases/compiler/a.ts(2,1): error TS1203: Export assignment cannot be used when targeting ECMAScript modules. Consider using 'export default' or another module format instead.
+tests/cases/compiler/b.ts(1,10): error TS2596: 'Foo' can only be imported by turning on the 'esModuleInterop' flag and using a default import.
+tests/cases/compiler/b.ts(1,21): error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'allowSyntheticDefaultImports' flag and referencing its default export.
+
+
+==== tests/cases/compiler/a.ts (1 errors) ====
+    class Foo {}
+    export = Foo;
+    ~~~~~~~~~~~~~
+!!! error TS1203: Export assignment cannot be used when targeting ECMAScript modules. Consider using 'export default' or another module format instead.
+
+==== tests/cases/compiler/b.ts (2 errors) ====
+    import { Foo } from './a';
+             ~~~
+!!! error TS2596: 'Foo' can only be imported by turning on the 'esModuleInterop' flag and using a default import.
+                        ~~~~~
+!!! error TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'allowSyntheticDefaultImports' flag and referencing its default export.

tests/baselines/reference/importNonExportedMember6.js

@@ -0,0 +1,16 @@
+//// [tests/cases/compiler/importNonExportedMember6.ts] ////
+
+//// [a.ts]
+class Foo {}
+export = Foo;
+
+//// [b.ts]
+import { Foo } from './a';
+
+//// [a.js]
+var Foo = /** @class */ (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+//// [b.js]

tests/baselines/reference/importNonExportedMember6.symbols

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+export = Foo;
+>Foo : Symbol(Foo, Decl(a.ts, 0, 0))
+
+=== tests/cases/compiler/b.ts ===
+import { Foo } from './a';
+>Foo : Symbol(Foo, Decl(b.ts, 0, 8))
+

tests/baselines/reference/importNonExportedMember6.types

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/a.ts ===
+class Foo {}
+>Foo : Foo
+
+export = Foo;
+>Foo : Foo
+
+=== tests/cases/compiler/b.ts ===
+import { Foo } from './a';
+>Foo : any
+