Issue better error for exporting primitive type (microsoft#36424)

* Issue better error for exporting primitive type

* Delete nonsense

Author: andrewbranch

src/compiler/checker.ts

@@ -1792,6 +1792,7 @@ namespace ts {
                         !checkAndReportErrorForMissingPrefix(errorLocation, name, nameArg!) && // TODO: GH#18217
                         !checkAndReportErrorForExtendingInterface(errorLocation) &&
                         !checkAndReportErrorForUsingTypeAsNamespace(errorLocation, name, meaning) &&
+                        !checkAndReportErrorForExportingPrimitiveType(errorLocation, name) &&
                         !checkAndReportErrorForUsingTypeAsValue(errorLocation, name, meaning) &&
                         !checkAndReportErrorForUsingNamespaceModuleAsValue(errorLocation, name, meaning) &&
                         !checkAndReportErrorForUsingValueAsType(errorLocation, name, meaning)) {
@@ -2053,9 +2054,21 @@ namespace ts {
             return false;
         }
 
+        function isPrimitiveTypeName(name: __String) {
+            return name === "any" || name === "string" || name === "number" || name === "boolean" || name === "never" || name === "unknown";
+        }
+
+        function checkAndReportErrorForExportingPrimitiveType(errorLocation: Node, name: __String): boolean {
+            if (isPrimitiveTypeName(name) && errorLocation.parent.kind === SyntaxKind.ExportSpecifier) {
+                error(errorLocation, Diagnostics.Cannot_export_0_Only_local_declarations_can_be_exported_from_a_module, name as string);
+                return true;
+            }
+            return false;
+        }
+
         function checkAndReportErrorForUsingTypeAsValue(errorLocation: Node, name: __String, meaning: SymbolFlags): boolean {
             if (meaning & (SymbolFlags.Value & ~SymbolFlags.NamespaceModule)) {
-                if (name === "any" || name === "string" || name === "number" || name === "boolean" || name === "never") {
+                if (isPrimitiveTypeName(name)) {
                     error(errorLocation, Diagnostics._0_only_refers_to_a_type_but_is_being_used_as_a_value_here, unescapeLeadingUnderscores(name));
                     return true;
                 }
@@ -33300,6 +33313,7 @@ namespace ts {
                 const id = node.expression as Identifier;
                 const sym = resolveEntityName(id, SymbolFlags.All, /*ignoreErrors*/ true, /*dontResolveAlias*/ true, node);
                 if (sym) {
+
                     markAliasReferenced(sym, id);
                     // If not a value, we're interpreting the identifier as a type export, along the lines of (`export { Id as default }`)
                     const target = sym.flags & SymbolFlags.Alias ? resolveAlias(sym) : sym;

src/compiler/diagnosticMessages.json

@@ -1127,6 +1127,7 @@
         "category": "Error",
         "code": 1378
     },
+
     "The types of '{0}' are incompatible between these types.": {
         "category": "Error",
         "code": 2200

tests/baselines/reference/exportNonLocalDeclarations.errors.txt

@@ -0,0 +1,12 @@
+tests/cases/conformance/externalModules/exportNonLocalDeclarations.ts(1,10): error TS2661: Cannot export 'string'. Only local declarations can be exported from a module.
+tests/cases/conformance/externalModules/exportNonLocalDeclarations.ts(2,15): error TS2661: Cannot export 'number'. Only local declarations can be exported from a module.
+
+
+==== tests/cases/conformance/externalModules/exportNonLocalDeclarations.ts (2 errors) ====
+    export { string };
+             ~~~~~~
+!!! error TS2661: Cannot export 'string'. Only local declarations can be exported from a module.
+    export type { number };
+                  ~~~~~~
+!!! error TS2661: Cannot export 'number'. Only local declarations can be exported from a module.
+    

tests/baselines/reference/exportNonLocalDeclarations.js

@@ -0,0 +1,8 @@
+//// [exportNonLocalDeclarations.ts]
+export { string };
+export type { number };
+
+
+//// [exportNonLocalDeclarations.js]
+"use strict";
+exports.__esModule = true;

tests/baselines/reference/exportNonLocalDeclarations.symbols

@@ -0,0 +1,7 @@
+=== tests/cases/conformance/externalModules/exportNonLocalDeclarations.ts ===
+export { string };
+>string : Symbol(string, Decl(exportNonLocalDeclarations.ts, 0, 8))
+
+export type { number };
+>number : Symbol(number, Decl(exportNonLocalDeclarations.ts, 1, 13))
+

tests/baselines/reference/exportNonLocalDeclarations.types

@@ -0,0 +1,7 @@
+=== tests/cases/conformance/externalModules/exportNonLocalDeclarations.ts ===
+export { string };
+>string : any
+
+export type { number };
+>number : any
+

tests/cases/conformance/externalModules/exportNonLocalDeclarations.ts

@@ -0,0 +1,2 @@
+export { string };
+export type { number };