Merge pull request #8453 from kunal-pmj/fix-singleton-query-parameter

Fix for Issue #8339

Author: HugoMario

modules/swagger-codegen/src/main/java/io/swagger/codegen/CodegenParameter.java

@@ -17,7 +17,7 @@ public class CodegenParameter {
     public boolean isString, isNumeric, isInteger, isLong, isNumber, isFloat, isDouble, isByteArray, isBinary, isBoolean, isDate, isDateTime, isUuid;
     public boolean isListContainer, isMapContainer;
     public boolean isFile, notFile;
-    public boolean isEnum;
+    public boolean isEnum, isConstEnumParam;
     public List<String> _enum;
     public Map<String, Object> allowableValues;
     public CodegenProperty items;
@@ -119,6 +119,7 @@ public CodegenParameter copy() {
         output.isEnum = this.isEnum;
         if (this._enum != null) {
             output._enum = new ArrayList<String>(this._enum);
+            this.isConstEnumParam = (this._enum.size() == 1 && this.required);
         }
         if (this.allowableValues != null) {
             output.allowableValues = new HashMap<String, Object>(this.allowableValues);

modules/swagger-codegen/src/main/resources/typescript-angular/api.service.mustache

@@ -124,19 +124,25 @@ export class {{classname}} {
      * @param reportProgress flag to report request and response progress.{{/useHttpClient}}
      */
     {{#useHttpClient}}
-    public {{nickname}}({{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}observe?: 'body', reportProgress?: boolean): Observable<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>;
-    public {{nickname}}({{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}observe?: 'response', reportProgress?: boolean): Observable<HttpResponse<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>>;
-    public {{nickname}}({{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}observe?: 'events', reportProgress?: boolean): Observable<HttpEvent<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>>;
-    public {{nickname}}({{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}observe: any = 'body', reportProgress: boolean = false ): Observable<any> {
+    public {{nickname}}({{#allParams}}{{^isConstEnumParam}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/isConstEnumParam}}{{/allParams}}observe?: 'body', reportProgress?: boolean): Observable<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>;
+    public {{nickname}}({{#allParams}}{{^isConstEnumParam}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/isConstEnumParam}}{{/allParams}}observe?: 'response', reportProgress?: boolean): Observable<HttpResponse<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>>;
+    public {{nickname}}({{#allParams}}{{^isConstEnumParam}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/isConstEnumParam}}{{/allParams}}observe?: 'events', reportProgress?: boolean): Observable<HttpEvent<{{#returnType}}{{{returnType}}}{{#isResponseTypeFile}}|undefined{{/isResponseTypeFile}}{{/returnType}}{{^returnType}}any{{/returnType}}>>;
+    public {{nickname}}({{#allParams}}{{^isConstEnumParam}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/isConstEnumParam}}{{/allParams}}observe: any = 'body', reportProgress: boolean = false ): Observable<any> {
     {{/useHttpClient}}
     {{^useHttpClient}}
     public {{nickname}}WithHttpInfo({{#allParams}}{{paramName}}{{^required}}?{{/required}}: {{{dataType}}}, {{/allParams}}extraHttpRequestParams?: RequestOptionsArgs): Observable<Response> {
     {{/useHttpClient}}
 {{#allParams}}
+
 {{#required}}
+        {{#isConstEnumParam}}
+        let {{paramName}} = {{{dataType}}};
+        {{/isConstEnumParam}}
+        {{^isConstEnumParam}}
         if ({{paramName}} === null || {{paramName}} === undefined) {
             throw new Error('Required parameter {{paramName}} was null or undefined when calling {{nickname}}.');
         }
+        {{/isConstEnumParam}}
 {{/required}}
 {{/allParams}}