fix(typescript-axios-slim): fix observe overloads

Author: scarf005

modules/openapi-generator/src/main/resources/typescript-axios-slim/apiInner.mustache

@@ -60,7 +60,7 @@ export interface {{classname}}Interface {
      * @deprecated{{/isDeprecated}}
      * @throws {RequiredError}
      */
-    {{nickname}}({{#allParams.0}}requestParameters{{^hasRequiredParams}}?{{/hasRequiredParams}}: {{classname}}{{operationIdCamelCase}}Request, {{/allParams.0}}options: ResponseObserveOptions): Promise<AxiosResponse<{{{returnType}}}{{^returnType}}void{{/returnType}}>>;
+    {{nickname}}({{#allParams.0}}{{#hasRequiredParams}}requestParameters: {{classname}}{{operationIdCamelCase}}Request, {{/hasRequiredParams}}{{^hasRequiredParams}}requestParameters: {{classname}}{{operationIdCamelCase}}Request | undefined, {{/hasRequiredParams}}{{/allParams.0}}options: ResponseObserveOptions): Promise<AxiosResponse<{{{returnType}}}{{^returnType}}void{{/returnType}}>>;
     {{nickname}}({{#allParams.0}}requestParameters{{^hasRequiredParams}}?{{/hasRequiredParams}}: {{classname}}{{operationIdCamelCase}}Request, {{/allParams.0}}options?: ObserveOptions): Promise<{{{returnType}}}{{^returnType}}void{{/returnType}}>;
 
 {{/operation}}
@@ -107,12 +107,13 @@ export class {{classname}} extends BaseAPI {
      * @deprecated{{/isDeprecated}}
      * @throws {RequiredError}
      */
-    public async {{nickname}}({{#allParams.0}}requestParameters: {{classname}}{{operationIdCamelCase}}Request{{^hasRequiredParams}} = {}{{/hasRequiredParams}}, {{/allParams.0}}options: ResponseObserveOptions): Promise<AxiosResponse<{{{returnType}}}{{^returnType}}void{{/returnType}}>>;
+    public async {{nickname}}({{#allParams.0}}{{#hasRequiredParams}}requestParameters: {{classname}}{{operationIdCamelCase}}Request, {{/hasRequiredParams}}{{^hasRequiredParams}}requestParameters: {{classname}}{{operationIdCamelCase}}Request | undefined, {{/hasRequiredParams}}{{/allParams.0}}options: ResponseObserveOptions): Promise<AxiosResponse<{{{returnType}}}{{^returnType}}void{{/returnType}}>>;
+    public async {{nickname}}({{#allParams.0}}requestParameters{{^hasRequiredParams}}?{{/hasRequiredParams}}: {{classname}}{{operationIdCamelCase}}Request, {{/allParams.0}}options?: ObserveOptions): Promise<{{{returnType}}}{{^returnType}}void{{/returnType}}>;
     public async {{nickname}}<TObserve extends ObserveOptions = ObserveOptions>({{#allParams.0}}requestParameters: {{classname}}{{operationIdCamelCase}}Request{{^hasRequiredParams}} = {}{{/hasRequiredParams}}, {{/allParams.0}}options: TObserve = {} as TObserve): Promise<TObserve extends ResponseObserveOptions ? AxiosResponse<{{{returnType}}}{{^returnType}}void{{/returnType}}> : {{{returnType}}}{{^returnType}}void{{/returnType}}> {
     {{#allParams.0}}
         validateRequestParameters('{{nickname}}', {{nickname}}RequestSchema, requestParameters);
     {{/allParams.0}}
-        const localVarPath = {{#pathParams}}withParams(`{{{path}}}`, { {{#pathParams}}"{{baseName}}": requestParameters.{{paramName}}, {{/pathParams}} }){{/pathParams}}{{^pathParams}}`{{{path}}}`{{/pathParams}};
+        const localVarPath = {{#pathParams.0}}withParams(`{{{path}}}`, { {{#pathParams}}"{{baseName}}": requestParameters.{{paramName}}, {{/pathParams}} }){{/pathParams.0}}{{^pathParams.0}}`{{{path}}}`{{/pathParams.0}};
         const localVarUrlObj = new URL(localVarPath, DUMMY_BASE_URL);
         const baseOptions = this.configuration ? this.configuration.baseOptions : undefined;
         const localVarObserve = options.observe ?? 'body';

modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/axios/TypeScriptAxiosSlimParityTest.java

@@ -134,6 +134,17 @@ public void shouldReturnPayloadDataFromObjectOrientedMethods() throws Exception
         assertTrue(apiSource.contains("return localVarResponse.data as TObserve extends ResponseObserveOptions ? AxiosResponse<"), "Slim API class should resolve axios response data directly");
     }
 
+    @Test(description = "slim: response overload keeps optional request object typescript-safe")
+    public void shouldUseUndefinedRequestParameterForOptionalRequestObjectResponseOverloads() throws Exception {
+        IdentitySurface slimSurface = generateIdentity("typescript-axios-slim", EDGE_CASE_SPEC, NO_CUSTOMIZER);
+        String apiSource = String.join(" ", slimSurface.apiFiles.values());
+
+        assertTrue(apiSource.contains("requestParameters: AnalyticsApiListReportsRequest | undefined, options: ResponseObserveOptions"),
+                "Slim API response overloads should avoid optional request parameters before required options");
+        assertTrue(apiSource.contains("public async listReports(requestParameters: AnalyticsApiListReportsRequest | undefined, options: ResponseObserveOptions): Promise<AxiosResponse<ReportList>>;"),
+                "Slim API class response overload should remain TypeScript-valid for optional request objects");
+    }
+
     @Test(description = "slim: observe options are exported for typed response access")
     public void shouldExportObserveOptionsForTypedResponseAccess() throws Exception {
         IdentitySurface slimSurface = generateIdentity("typescript-axios-slim", EDGE_CASE_SPEC, NO_CUSTOMIZER);