[csharp][restsharp] add throwOnAnyError option to surface client errors

docs/generators/csharp.md

@@ -47,6 +47,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |returnICollection|Return ICollection<T> instead of the concrete type.| |false|
 |sourceFolder|source folder for generated code| |src|
 |targetFramework|The target .NET framework version. To target multiple frameworks, use `;` as the separator, e.g. `netstandard2.1;netcoreapp3.1`|<dl><dt>**netstandard1.3**</dt><dd>.NET Standard 1.3</dd><dt>**netstandard1.4**</dt><dd>.NET Standard 1.4</dd><dt>**netstandard1.5**</dt><dd>.NET Standard 1.5</dd><dt>**netstandard1.6**</dt><dd>.NET Standard 1.6</dd><dt>**netstandard2.0**</dt><dd>.NET Standard 2.0</dd><dt>**netstandard2.1**</dt><dd>.NET Standard 2.1</dd><dt>**net47**</dt><dd>.NET Framework 4.7</dd><dt>**net48**</dt><dd>.NET Framework 4.8</dd><dt>**net8.0**</dt><dd>.NET 8.0 (End of Support 10 November 2026)</dd><dt>**net9.0**</dt><dd>.NET 9.0 (End of Support 10 November 2026)</dd><dt>**net10.0**</dt><dd>.NET 10.0 (End of Support 14 November 2028)</dd></dl>|net10.0|
+|throwOnAnyError|Configure RestSharp to rethrow deserialization and transport errors instead of swallowing them into RestResponse.ErrorException (which the default ToApiResponse&lt;T&gt; discards as null Data). Recommended for production use to surface bugs that would otherwise be invisible. (restsharp only)| |false|
 |useCollection|Deserialize array types to Collection&lt;T&gt; instead of List&lt;T&gt;.| |false|
 |useDateTimeForDate|Use DateTime to model date properties even if DateOnly supported. (.net 6.0+ only)| |false|
 |useDateTimeOffset|Use DateTimeOffset to model date-time properties| |false|

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

@@ -122,6 +122,7 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
     protected boolean supportsFileParameters = Boolean.TRUE;
     protected boolean supportsDateOnly = Boolean.FALSE;
     protected boolean useIntForTimeout = Boolean.FALSE;
+    protected boolean throwOnAnyError = Boolean.FALSE;
 
     @Setter protected boolean validatable = Boolean.TRUE;
     @Setter protected boolean equatable = Boolean.FALSE;
@@ -132,6 +133,7 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
     private static final String OPERATION_PARAMETER_SORTING_KEY = "operationParameterSorting";
     private static final String MODEL_PROPERTY_SORTING_KEY = "modelPropertySorting";
     private static final String USE_INT_FOR_TIMEOUT = "useIntForTimeout";
+    private static final String THROW_ON_ANY_ERROR = "throwOnAnyError";
 
     enum SortingMethod {
         DEFAULT,
@@ -249,6 +251,10 @@ public CSharpClientCodegen() {
                 "Use int for Timeout (fall back to v7.9.0 templates). This option (for restsharp only) will be deprecated so please migrated to TimeSpan instead.",
                 String.valueOf(this.useIntForTimeout));
 
+        addSwitch(CSharpClientCodegen.THROW_ON_ANY_ERROR,
+                "Configure RestSharp to rethrow deserialization and transport errors instead of swallowing them into RestResponse.ErrorException (which the default ToApiResponse<T> discards as null Data). Recommended for production use to surface bugs that would otherwise be invisible. (restsharp only)",
+                this.throwOnAnyError);
+
         CliOption framework = new CliOption(
                 CodegenConstants.DOTNET_FRAMEWORK,
                 CodegenConstants.DOTNET_FRAMEWORK_DESC
@@ -871,6 +877,7 @@ public void processOpts() {
         syncBooleanProperty(additionalProperties, "useSourceGeneration", this::setUseSourceGeneration, this.useSourceGeneration);
         syncBooleanProperty(additionalProperties, "supportsDateOnly", this::setSupportsDateOnly, this.supportsDateOnly);
         syncBooleanProperty(additionalProperties, "useIntForTimeout", this::setUseIntForTimeout, this.useIntForTimeout);
+        syncBooleanProperty(additionalProperties, "throwOnAnyError", this::setThrowOnAnyError, this.throwOnAnyError);
 
         final String testPackageName = testPackageName();
         String packageFolder = sourceFolder + File.separator + packageName;
@@ -1244,6 +1251,10 @@ public void setUseIntForTimeout(Boolean useIntForTimeout) {
         this.useIntForTimeout = useIntForTimeout;
     }
 
+    public void setThrowOnAnyError(Boolean throwOnAnyError) {
+        this.throwOnAnyError = throwOnAnyError;
+    }
+
     public void setSupportsRetry(Boolean supportsRetry) {
         this.supportsRetry = supportsRetry;
     }

modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache

@@ -467,7 +467,8 @@ namespace {{packageName}}.Client
                 Proxy = configuration.Proxy,
                 UserAgent = configuration.UserAgent,
                 UseDefaultCredentials = configuration.UseDefaultCredentials,
-                RemoteCertificateValidationCallback = configuration.RemoteCertificateValidationCallback
+                RemoteCertificateValidationCallback = configuration.RemoteCertificateValidationCallback{{#throwOnAnyError}},
+                ThrowOnAnyError = true{{/throwOnAnyError}}
             };
             setOptions(clientOptions);
 
@@ -560,16 +561,21 @@ namespace {{packageName}}.Client
 
         private async Task<RestResponse<T>> DeserializeRestResponseFromPolicyAsync<T>(RestClient client, RestRequest request, PolicyResult<RestResponse> policyResult, CancellationToken cancellationToken = default)
         {
-            if (policyResult.Outcome == OutcomeType.Successful) 
+            if (policyResult.Outcome == OutcomeType.Successful)
             {
                 return await client.Deserialize<T>(policyResult.Result, cancellationToken).ConfigureAwait(false);
             }
             else
             {
+                {{#throwOnAnyError}}
+                throw policyResult.FinalException;
+                {{/throwOnAnyError}}
+                {{^throwOnAnyError}}
                 return new RestResponse<T>(request)
                 {
                     ErrorException = policyResult.FinalException
                 };
+                {{/throwOnAnyError}}
             }
         }
 

modules/openapi-generator/src/main/resources/csharp/ApiClient.v790.mustache

@@ -552,16 +552,21 @@ namespace {{packageName}}.Client
 
         private async Task<RestResponse<T>> DeserializeRestResponseFromPolicyAsync<T>(RestClient client, RestRequest request, PolicyResult<RestResponse> policyResult, CancellationToken cancellationToken = default)
         {
-            if (policyResult.Outcome == OutcomeType.Successful) 
+            if (policyResult.Outcome == OutcomeType.Successful)
             {
                 return await client.Deserialize<T>(policyResult.Result, cancellationToken);
             }
             else
             {
+                {{#throwOnAnyError}}
+                throw policyResult.FinalException;
+                {{/throwOnAnyError}}
+                {{^throwOnAnyError}}
                 return new RestResponse<T>(request)
                 {
                     ErrorException = policyResult.FinalException
                 };
+                {{/throwOnAnyError}}
             }
         }