TS: Fix handling of 'export ='

Author: asger-semmle

javascript/extractor/lib/typescript/src/main.ts

@@ -360,7 +360,9 @@ function handleOpenProjectCommand(command: OpenProjectCommand) {
     function getEffectiveExportTarget(symbol: ts.Symbol) {
         if (symbol.exports != null && symbol.exports.has(ts.InternalSymbolName.ExportEquals)) {
             let exportAlias = symbol.exports.get(ts.InternalSymbolName.ExportEquals);
-            return typeChecker.getAliasedSymbol(exportAlias);
+            if (exportAlias.flags & ts.SymbolFlags.Alias) {
+                return typeChecker.getAliasedSymbol(exportAlias);
+            }
         }
         return symbol;
     }

javascript/ql/test/library-tests/TypeScript/RegressionTests/ExportEqualsExpr/extern.d.ts

@@ -0,0 +1,14 @@
+class Foo {}
+
+declare module 'foo' {
+  export = new Foo();
+}
+
+declare module 'bar' {
+  import * as baz from "baz";
+  export = baz;
+}
+
+declare module 'baz' {
+  export class C {}
+}

javascript/ql/test/library-tests/TypeScript/RegressionTests/ExportEqualsExpr/test.expected

@@ -0,0 +1,7 @@
+| "bar" in global scope |
+| C in module 'bar' |
+| Foo in global scope |
+| Foo in tst.ts |
+| module 'bar' |
+| module 'foo' |
+| tst.ts |

javascript/ql/test/library-tests/TypeScript/RegressionTests/ExportEqualsExpr/test.ql

@@ -0,0 +1,4 @@
+import javascript
+
+from CanonicalName name
+select name

javascript/ql/test/library-tests/TypeScript/RegressionTests/ExportEqualsExpr/tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "include": ["."],
+  "compilerOptions": {
+    "esModuleInterop": true
+  }
+}

javascript/ql/test/library-tests/TypeScript/RegressionTests/ExportEqualsExpr/tst.ts

@@ -0,0 +1,5 @@
+import self from "./tst";
+
+class Foo {}
+
+export = new Foo();