Fix46246

src/compiler/checker.ts

@@ -2478,7 +2478,12 @@ namespace ts {
         function checkAndReportErrorForUsingTypeAsValue(errorLocation: Node, name: __String, meaning: SymbolFlags): boolean {
             if (meaning & (SymbolFlags.Value & ~SymbolFlags.NamespaceModule)) {
                 if (isPrimitiveTypeName(name)) {
-                    error(errorLocation, Diagnostics._0_only_refers_to_a_type_but_is_being_used_as_a_value_here, unescapeLeadingUnderscores(name));
+                    if (isExtendedByInterface(errorLocation)) {
+                        error(errorLocation, Diagnostics.An_interface_cannot_extend_a_primitive_type_like_0_an_interface_can_only_extend_named_types_and_classes, unescapeLeadingUnderscores(name));
+                    }
+                    else {
+                        error(errorLocation, Diagnostics._0_only_refers_to_a_type_but_is_being_used_as_a_value_here, unescapeLeadingUnderscores(name));
+                    }
                     return true;
                 }
                 const symbol = resolveSymbol(resolveName(errorLocation, name, SymbolFlags.Type & ~SymbolFlags.Value, /*nameNotFoundMessage*/undefined, /*nameArg*/ undefined, /*isUse*/ false));
@@ -2499,6 +2504,17 @@ namespace ts {
             return false;
         }
 
+        function isExtendedByInterface(node: Node): boolean {
+            const grandparent = node.parent.parent;
+            const parentOfGrandparent = grandparent.parent;
+            if(grandparent && parentOfGrandparent){
+                const isExtending = isHeritageClause(grandparent) && grandparent.token === SyntaxKind.ExtendsKeyword;
+                const isInterface = isInterfaceDeclaration(parentOfGrandparent);
+                return isExtending && isInterface;
+            }
+            return false;
+        }
+
         function maybeMappedType(node: Node, symbol: Symbol) {
             const container = findAncestor(node.parent, n =>
                 isComputedPropertyName(n) || isPropertySignature(n) ? false : isTypeLiteralNode(n) || "quit") as TypeLiteralNode | undefined;

src/compiler/diagnosticMessages.json

@@ -3475,6 +3475,10 @@
         "category": "Error",
         "code": 2839
     },
+    "An interface cannot extend a primitive type like '{0}'; an interface can only extend named types and classes": {
+        "category": "Error",
+        "code": 2840
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",

tests/baselines/reference/errorLocationForInterfaceExtension.errors.txt

@@ -1,10 +1,10 @@
-tests/cases/compiler/errorLocationForInterfaceExtension.ts(3,21): error TS2693: 'string' only refers to a type, but is being used as a value here.
+tests/cases/compiler/errorLocationForInterfaceExtension.ts(3,21): error TS2840: An interface cannot extend a primitive type like 'string'; an interface can only extend named types and classes
 
 
 ==== tests/cases/compiler/errorLocationForInterfaceExtension.ts (1 errors) ====
     var n = '';
 
     interface x extends string { }
                         ~~~~~~
-!!! error TS2693: 'string' only refers to a type, but is being used as a value here.
+!!! error TS2840: An interface cannot extend a primitive type like 'string'; an interface can only extend named types and classes
 

tests/baselines/reference/interfacedeclWithIndexerErrors.errors.txt

@@ -3,9 +3,11 @@ tests/cases/compiler/interfacedeclWithIndexerErrors.ts(14,5): error TS2411: Prop
 tests/cases/compiler/interfacedeclWithIndexerErrors.ts(15,5): error TS2411: Property 'p5' of type '(s: number) => string' is not assignable to 'string' index type '() => string'.
 tests/cases/compiler/interfacedeclWithIndexerErrors.ts(19,5): error TS2411: Property 'f3' of type '(a: string) => number' is not assignable to 'string' index type '() => string'.
 tests/cases/compiler/interfacedeclWithIndexerErrors.ts(20,5): error TS2411: Property 'f4' of type '(s: number) => string' is not assignable to 'string' index type '() => string'.
+tests/cases/compiler/interfacedeclWithIndexerErrors.ts(44,21): error TS2840: An interface cannot extend a primitive type like 'number'; an interface can only extend named types and classes
+tests/cases/compiler/interfacedeclWithIndexerErrors.ts(48,18): error TS2693: 'string' only refers to a type, but is being used as a value here.
 
 
-==== tests/cases/compiler/interfacedeclWithIndexerErrors.ts (5 errors) ====
+==== tests/cases/compiler/interfacedeclWithIndexerErrors.ts (7 errors) ====
     interface a0 {
         (): string;
         (a, b, c?: string): number;
@@ -59,6 +61,17 @@ tests/cases/compiler/interfacedeclWithIndexerErrors.ts(20,5): error TS2411: Prop
     interface d extends a {
     }
 
+    interface e extends number {
+                        ~~~~~~
+!!! error TS2840: An interface cannot extend a primitive type like 'number'; an interface can only extend named types and classes
+    }
+
+    interface f {
+        prop: typeof string;
+                     ~~~~~~
+!!! error TS2693: 'string' only refers to a type, but is being used as a value here.
+    }
+
     class c1 implements a {
     }
     var instance2 = new c1();

tests/baselines/reference/interfacedeclWithIndexerErrors.js

@@ -42,6 +42,13 @@ interface c extends a, b {
 interface d extends a {
 }
 
+interface e extends number {
+}
+
+interface f {
+    prop: typeof string;
+}
+
 class c1 implements a {
 }
 var instance2 = new c1();

tests/baselines/reference/interfacedeclWithIndexerErrors.symbols

@@ -84,11 +84,22 @@ interface d extends a {
 >a : Symbol(a, Decl(interfacedeclWithIndexerErrors.ts, 29, 1))
 }
 
+interface e extends number {
+>e : Symbol(e, Decl(interfacedeclWithIndexerErrors.ts, 41, 1))
+}
+
+interface f {
+>f : Symbol(f, Decl(interfacedeclWithIndexerErrors.ts, 44, 1))
+
+    prop: typeof string;
+>prop : Symbol(f.prop, Decl(interfacedeclWithIndexerErrors.ts, 46, 13))
+}
+
 class c1 implements a {
->c1 : Symbol(c1, Decl(interfacedeclWithIndexerErrors.ts, 41, 1))
+>c1 : Symbol(c1, Decl(interfacedeclWithIndexerErrors.ts, 48, 1))
 >a : Symbol(a, Decl(interfacedeclWithIndexerErrors.ts, 29, 1))
 }
 var instance2 = new c1();
->instance2 : Symbol(instance2, Decl(interfacedeclWithIndexerErrors.ts, 45, 3))
->c1 : Symbol(c1, Decl(interfacedeclWithIndexerErrors.ts, 41, 1))
+>instance2 : Symbol(instance2, Decl(interfacedeclWithIndexerErrors.ts, 52, 3))
+>c1 : Symbol(c1, Decl(interfacedeclWithIndexerErrors.ts, 48, 1))
 

tests/baselines/reference/interfacedeclWithIndexerErrors.types

@@ -70,6 +70,15 @@ interface c extends a, b {
 interface d extends a {
 }
 
+interface e extends number {
+}
+
+interface f {
+    prop: typeof string;
+>prop : any
+>string : any
+}
+
 class c1 implements a {
 >c1 : c1
 }

tests/cases/compiler/interfacedeclWithIndexerErrors.ts

@@ -41,6 +41,13 @@ interface c extends a, b {
 interface d extends a {
 }
 
+interface e extends number {
+}
+
+interface f {
+    prop: typeof string;
+}
+
 class c1 implements a {
 }
 var instance2 = new c1();