From 5a5f6d6922243df0fca33f12ba3fa7f8fd12da7a Mon Sep 17 00:00:00 2001
From: Ivan ROGER <contact@ivan-roger.fr>
Date: Wed, 29 Oct 2025 10:35:39 +0100
Subject: [PATCH] Fix explode query params for typescript-fetch

Fixes: #10438
---
 .../main/resources/typescript-fetch/apis.mustache    | 12 ++++++++++++
 .../builds/default-v3.0/apis/FakeApi.ts              |  4 +++-
 .../builds/snakecase-discriminator/apis/FakeApi.ts   |  4 +++-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
index ab7411c8bb14..5f14d753c854 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
@@ -133,6 +133,17 @@ export class {{classname}} extends runtime.BaseAPI {
         {{/isArray}}
         {{^isArray}}
         if (requestParameters['{{paramName}}'] != null) {
+            {{#isExplode}}
+            {{#isContainer}}
+            for (let key of Object.keys(requestParameters['{{paramName}}'])) {
+                queryParameters[key] = requestParameters['{{paramName}}'][key];
+            }
+            {{/isContainer}}
+            {{^isContainer}}
+            queryParameters['{{baseName}}'] = requestParameters['{{paramName}}'];
+            {{/isContainer}}
+            {{/isExplode}}
+            {{^isExplode}}
             {{#isDateTimeType}}
             queryParameters['{{baseName}}'] = (requestParameters['{{paramName}}'] as any).toISOString();
             {{/isDateTimeType}}
@@ -144,6 +155,7 @@ export class {{classname}} extends runtime.BaseAPI {
             queryParameters['{{baseName}}'] = requestParameters['{{paramName}}'];
             {{/isDateType}}
             {{/isDateTimeType}}
+            {{/isExplode}}
         }
 
         {{/isArray}}
diff --git a/samples/client/petstore/typescript-fetch/builds/default-v3.0/apis/FakeApi.ts b/samples/client/petstore/typescript-fetch/builds/default-v3.0/apis/FakeApi.ts
index 72800d8405f2..0eef4125671b 100644
--- a/samples/client/petstore/typescript-fetch/builds/default-v3.0/apis/FakeApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default-v3.0/apis/FakeApi.ts
@@ -1214,7 +1214,9 @@ export class FakeApi extends runtime.BaseAPI {
         }
 
         if (requestParameters['language'] != null) {
-            queryParameters['language'] = requestParameters['language'];
+            for (let key of Object.keys(requestParameters['language'])) {
+                queryParameters[key] = requestParameters['language'][key];
+            }
         }
 
         if (requestParameters['allowEmpty'] != null) {
diff --git a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/apis/FakeApi.ts b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/apis/FakeApi.ts
index 4c6c8605a6d7..21ad0984b848 100644
--- a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/apis/FakeApi.ts
+++ b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/apis/FakeApi.ts
@@ -1072,7 +1072,9 @@ export class FakeApi extends runtime.BaseAPI {
         }
 
         if (requestParameters['language'] != null) {
-            queryParameters['language'] = requestParameters['language'];
+            for (let key of Object.keys(requestParameters['language'])) {
+                queryParameters[key] = requestParameters['language'][key];
+            }
         }
 
         if (requestParameters['allowEmpty'] != null) {