fix(typescript-fetch): allow null for required nullable parameters

modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache

@@ -118,10 +118,10 @@ export class {{classname}} extends runtime.BaseAPI {
     async {{nickname}}RequestOpts({{#allParams.0}}requestParameters: {{#prefixParameterInterfaces}}{{classname}}{{/prefixParameterInterfaces}}{{operationIdCamelCase}}Request{{/allParams.0}}): Promise<runtime.RequestOpts> {
         {{#allParams}}
         {{#required}}
-        if (requestParameters['{{paramName}}'] == null) {
+        if (requestParameters['{{paramName}}'] {{#isBodyParam}}{{#isNullable}}=== undefined{{/isNullable}}{{^isNullable}}== null{{/isNullable}}{{/isBodyParam}}{{^isBodyParam}}== null{{/isBodyParam}}) {
             throw new runtime.RequiredError(
                 '{{paramName}}',
-                'Required parameter "{{paramName}}" was null or undefined when calling {{nickname}}().'
+                'Required parameter "{{paramName}}" was {{#isBodyParam}}{{#isNullable}}undefined{{/isNullable}}{{^isNullable}}null or undefined{{/isNullable}}{{/isBodyParam}}{{^isBodyParam}}null or undefined{{/isBodyParam}} when calling {{nickname}}().'
             );
         }
 

modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java

@@ -667,6 +667,27 @@ public void testOptionalNullableFieldDeserializesToNull() throws Exception {
         TestUtils.assertFileNotContains(modelPath, "json['required_property'] === undefined ? undefined : json['required_property'] === null ? null :");
     }
 
+    @Test(description = "Required nullable bodies should reject undefined but accept null (fix #23493)")
+    public void testRequiredNullableBodyRejectsOnlyUndefined() throws Exception {
+        File output = generate(
+            Collections.emptyMap(),
+            "src/test/resources/3_0/typescript-fetch/issue_23493.yaml"
+        );
+
+        Path apiPath = Paths.get(output + "/apis/DefaultApi.ts");
+        TestUtils.assertFileContains(apiPath,
+                "if (requestParameters['body'] === undefined)",
+                "Required parameter \"body\" was undefined when calling nullableBody().",
+                "body: boolean | null;",
+                "body: requestParameters['body'] as any");
+        TestUtils.assertFileContains(apiPath,
+                "if (requestParameters['body'] == null)",
+                "Required parameter \"body\" was null or undefined when calling nonNullableBody().");
+        TestUtils.assertFileContains(apiPath,
+                "if (requestParameters['requiredNullableQuery'] == null)",
+                "Required parameter \"requiredNullableQuery\" was null or undefined when calling nullableBody().");
+    }
+
     @Test(description = "Verify Omit uses the camelCase property name instead of the baseName for readOnly fields")
     public void testIssue23380_OmitUsesCorrectPropertyName() throws Exception {
         File output = generate(

modules/openapi-generator/src/test/resources/3_0/typescript-fetch/issue_23493.yaml

@@ -0,0 +1,37 @@
+openapi: 3.0.1
+info:
+  title: Required nullable request body
+  version: 1.0.0
+paths:
+  /nullable:
+    post:
+      operationId: nullableBody
+      parameters:
+        - name: requiredNullableQuery
+          in: query
+          required: true
+          schema:
+            type: string
+            nullable: true
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: boolean
+              nullable: true
+      responses:
+        '200':
+          description: OK
+  /non-nullable:
+    post:
+      operationId: nonNullableBody
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: boolean
+      responses:
+        '200':
+          description: OK

samples/client/petstore/typescript-fetch/builds/default-v3.0/apis/FakeApi.ts

@@ -589,10 +589,10 @@ export class FakeApi extends runtime.BaseAPI {
      * Creates request options for testBodyWithBinary without sending the request
      */
     async testBodyWithBinaryRequestOpts(requestParameters: TestBodyWithBinaryRequest): Promise<runtime.RequestOpts> {
-        if (requestParameters['body'] == null) {
+        if (requestParameters['body'] === undefined) {
             throw new runtime.RequiredError(
                 'body',
-                'Required parameter "body" was null or undefined when calling testBodyWithBinary().'
+                'Required parameter "body" was undefined when calling testBodyWithBinary().'
             );
         }
 

samples/client/petstore/typescript-fetch/builds/kebab-case/apis/fake-api.ts

@@ -589,10 +589,10 @@ export class FakeApi extends runtime.BaseAPI {
      * Creates request options for testBodyWithBinary without sending the request
      */
     async testBodyWithBinaryRequestOpts(requestParameters: TestBodyWithBinaryRequest): Promise<runtime.RequestOpts> {
-        if (requestParameters['body'] == null) {
+        if (requestParameters['body'] === undefined) {
             throw new runtime.RequiredError(
                 'body',
-                'Required parameter "body" was null or undefined when calling testBodyWithBinary().'
+                'Required parameter "body" was undefined when calling testBodyWithBinary().'
             );
         }
 

samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/apis/FakeApi.ts

@@ -515,10 +515,10 @@ export class FakeApi extends runtime.BaseAPI {
      * Creates request options for testBodyWithBinary without sending the request
      */
     async testBodyWithBinaryRequestOpts(requestParameters: TestBodyWithBinaryRequest): Promise<runtime.RequestOpts> {
-        if (requestParameters['body'] == null) {
+        if (requestParameters['body'] === undefined) {
             throw new runtime.RequiredError(
                 'body',
-                'Required parameter "body" was null or undefined when calling testBodyWithBinary().'
+                'Required parameter "body" was undefined when calling testBodyWithBinary().'
             );
         }