fix(web): make type of additionalFilters in ImageController.findImages (backport #1877)

gate-web/src/main/groovy/com/netflix/spinnaker/gate/controllers/ImageController.groovy

@@ -49,7 +49,7 @@ class ImageController {
                        @RequestParam(value = "account", required = false) String account,
                        @RequestParam(value = "count", required = false) Integer count,
                        HttpServletRequest httpServletRequest) {
-    def additionalFilters = httpServletRequest.getParameterNames().findAll { String parameterName ->
+    Map<String, String> additionalFilters = httpServletRequest.getParameterNames().findAll { String parameterName ->
       !["provider", "q", "region", "account", "count"].contains(parameterName.toLowerCase())
     }.collectEntries { String parameterName ->
       [parameterName, httpServletRequest.getParameter(parameterName)]

gate-web/src/test/java/com/netflix/spinnaker/gate/controllers/ImageControllerTest.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2025 Salesforce, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.netflix.spinnaker.gate.controllers;
+
+import static org.mockito.Mockito.verify;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+import static org.springframework.test.web.servlet.setup.MockMvcBuilders.webAppContextSetup;
+
+import com.netflix.spinnaker.gate.Main;
+import com.netflix.spinnaker.gate.services.ImageService;
+import java.util.Map;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestInfo;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.test.context.TestPropertySource;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.web.context.WebApplicationContext;
+
+@SpringBootTest(classes = Main.class)
+@TestPropertySource(properties = "spring.config.location=classpath:gate-test.yml")
+class ImageControllerTest {
+
+  private MockMvc webAppMockMvc;
+
+  @Autowired private WebApplicationContext webApplicationContext;
+
+  @MockBean ImageService imageService;
+
+  @BeforeEach
+  void init(TestInfo testInfo) {
+    System.out.println("--------------- Test " + testInfo.getDisplayName());
+
+    webAppMockMvc = webAppContextSetup(webApplicationContext).build();
+  }
+
+  @Test
+  void testFindImages() throws Exception {
+    String provider = "my-provider";
+    String query = "my-query";
+    String region = "my-region";
+    String account = "my-account";
+    int count = 17;
+    String rateLimitHeader = "my-rate-limit-header";
+
+    Map<String, String> additionalFilters = Map.of("other", "my-special-header");
+
+    webAppMockMvc
+        .perform(
+            get("/images/find")
+                .param("provider", provider)
+                .param("q", query)
+                .param("region", region)
+                .param("account", account)
+                .param("count", String.valueOf(count))
+                .param("other", "my-special-header")
+                .header("X-RateLimit-Header", rateLimitHeader))
+        .andDo(print())
+        .andExpect(status().isOk());
+
+    verify(imageService)
+        .search(provider, query, region, account, count, additionalFilters, rateLimitHeader);
+  }
+}