fix: treat an exported namespace as a value export (#285)

Co-authored-by: Lucas Treffenstädt <lucas.treffenstaedt@tngtech.com>

src/transform/ExportsFixer.ts

@@ -31,6 +31,7 @@ export class ExportsFixer {
         const exportedName = e.name.text;
         const localName = e.propertyName?.text ?? e.name.text;
         const kind = types.some(node => node.getText() === localName) && !values.some(node => node.getText() === localName) ? 'type' as const : 'value' as const;
+        this.DEBUG && (console.log(`export ${localName} as ${exportedName} is a ${kind}`));
         return {
           exportedName,
           localName,
@@ -96,6 +97,10 @@ export class ExportsFixer {
         continue;
       }
       if (ts.isModuleDeclaration(statement)) {
+        if (statement.name && ts.isIdentifier(statement.name)) {
+          this.DEBUG && console.log(`${statement.name.getFullText()} is a value (from module declaration)`);
+          values.push(statement.name);
+        }
         recurseInto(statement.getChildren());
         continue;
       }

tests/testcases/issue-284/expected.d.ts

@@ -0,0 +1,7 @@
+interface MyInterface {
+  a: string;
+}
+declare namespace MyInterface {
+  export const b: string;
+}
+export { MyInterface };

tests/testcases/issue-284/index.d.ts

@@ -0,0 +1,7 @@
+export interface MyInterface {
+  a: string;
+}
+
+export namespace MyInterface {
+  export const b: string;
+}