Updates the go server generator to allow strict response decoding by default, and also allow a permissive option

Author: Chimdi511

docs/generators/go-server.md

@@ -29,6 +29,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |router|Specify the router which should be used.|<dl><dt>**mux**</dt><dd>mux</dd><dt>**chi**</dt><dd>chi</dd></dl>|mux|
 |serverPort|The network port the generated server binds to| |8080|
 |sourceFolder|source folder for generated code| |go|
+|strictResponseDecoding| Generated server rejects extra JSON fields | |true|
 
 ## IMPORT MAPPING
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoServerCodegen.java

@@ -35,24 +35,27 @@
 import static org.openapitools.codegen.utils.StringUtils.camelize;
 
 public class GoServerCodegen extends AbstractGoCodegen {
-
+    public static final String STRICT_RESPONSE_DECODING = "strictResponseDecoding";
+    protected boolean strictResponseDecoding = true;
     /**
      * Name of additional property for switching routers
      */
     private static final String ROUTER_SWITCH = "router";
+    
+    
 
     /**
      * Description of additional property for switching routers
      */
     private static final String ROUTER_SWITCH_DESC = "Specify the router which should be used.";
-
+    
     /**
      * List of available routers
      */
     private static final String[] ROUTERS = {"mux", "chi"};
-
+    
     private final Logger LOGGER = LoggerFactory.getLogger(GoServerCodegen.class);
-
+    
     @Setter protected String packageVersion = "1.0.0";
     @Setter protected int serverPort = 8080;
     protected String projectName = "openapi-server";
@@ -92,6 +95,7 @@ public GoServerCodegen() {
         // set the output folder here
         outputFolder = "generated-code/go";
 
+        cliOptions.add(new CliOption(STRICT_RESPONSE_DECODING, "If true, server JSON decoders call DisallowUnknownFields").defaultValue("true"));
         cliOptions.add(new CliOption(CodegenConstants.SOURCE_FOLDER, CodegenConstants.SOURCE_FOLDER_DESC)
                 .defaultValue(sourceFolder));
 
@@ -132,6 +136,9 @@ public GoServerCodegen() {
         optOutputAsLibrary.setType("bool");
         optOutputAsLibrary.defaultValue(outputAsLibrary.toString());
         cliOptions.add(optOutputAsLibrary);
+
+        cliOptions.add(new CliOption(STRICT_RESPONSE_DECODING, "If true, responses are decoded with DisallowUnknownFields (strict); " + "if false, unknown JSON fields are ignored (permissive)").defaultValue("true"));
+
         /*
          * Models.  You can write model files using the modelTemplateFiles map.
          * if you want to create one template for file, you can do so here.
@@ -192,6 +199,9 @@ public void processOpts() {
          * Additional Properties.  These values can be passed to the templates and
          * are available in models, apis, and supporting files
          */
+        if (additionalProperties.containsKey(STRICT_RESPONSE_DECODING)){
+            strictResponseDecoding = Boolean.parseBoolean(additionalProperties.get(STRICT_RESPONSE_DECODING).toString());
+        }
         if (additionalProperties.containsKey(CodegenConstants.PACKAGE_NAME)) {
             setPackageName((String) additionalProperties.get(CodegenConstants.PACKAGE_NAME));
         } else {
@@ -268,6 +278,7 @@ public void processOpts() {
             routers.put(router, router.equals(propRouter));
         }
         additionalProperties.put("routers", routers);
+        additionalProperties.put("strictResponseDecoding", strictResponseDecoding);
 
         modelPackage = packageName;
         apiPackage = packageName;

modules/openapi-generator/src/main/resources/go-server/controller-api.mustache

@@ -612,9 +612,9 @@ func (c *{{classname}}Controller) {{nickname}}(w http.ResponseWriter, r *http.Re
 	{{#isBodyParam}}
 	var {{paramName}}Param {{dataType}}
 	d := json.NewDecoder(r.Body)
-	{{^isAdditionalPropertiesTrue}}
+	{{#strictResponseDecoding}}
 	d.DisallowUnknownFields()
-	{{/isAdditionalPropertiesTrue}}
+	{{/strictResponseDecoding}}
 	if err := d.Decode(&{{paramName}}Param); err != nil {{^required}}&& !errors.Is(err, io.EOF) {{/required}}{
 		c.errorHandler(w, r, &ParsingError{Err: err}, nil)
 		return