Improve esm compatability

src/targets/typescript.ts

@@ -33,7 +33,7 @@ export class TypescriptTarget extends CompileTarget {
    }
 
    private generateImport(imports: string, path: string) {
-      return `import ${imports} from "${path + (this.flavour === "esm" ? ".ts" : "")
+      return `import ${imports} from "${path + (this.flavour === "esm" ? ".js" : "")
          }";\n`;
    }
 
@@ -207,7 +207,7 @@ export class TypescriptTarget extends CompileTarget {
       this.writeFormattedFile(
          "service_client.ts",
          this.generateImport(
-            "{ RequestObject, ResponseObject, ErrorCodes, Logging }",
+            "{ type RequestObject, type ResponseObject, ErrorCodes, Logging }",
             "./service_base"
          ) +
          this.generateImport(" { VerificationError }", "./ts_base") +

templates/ts_base.ts

@@ -1,5 +1,3 @@
-import { isGeneratorFunction } from "util/types";
-
 function form_verficiation_error_message(type?: string, field?: string) {
    let msg = "Parameter verification failed! ";
    if (type && field) {