fix(client configuration): default headers not applied

Sources/AlgoliaSearchClient/Models/Settings/Auxiliary/CustomRankingCriterion.swift

@@ -32,7 +32,7 @@ extension CustomRankingCriterion: RawRepresentable {
     guard
       let prefixedString = PrefixedString(rawValue: rawValue),
       let prefix = Prefix(rawValue: prefixedString.prefix) else {
-        return nil
+      return nil
     }
     switch prefix {
     case .asc:

Sources/AlgoliaSearchClient/Transport/HTTP/HTTPRequestBuilder.swift

@@ -32,6 +32,11 @@ class HTTPRequestBuilder {
     let timeout = command.requestOptions?.timeout(for: command.callType) ?? configuration.timeout(for: command.callType)
     var request = URLRequest(command: command).setIfNotNil(\.credentials, to: credentials)
     request.addValue(UserAgentController.httpHeaderValue, forHTTPHeaderField: HTTPHeaderKey.userAgent.rawValue)
+    if let defaultHeaders = configuration.defaultHeaders {
+      for header in defaultHeaders {
+        request.addValue(header.value, forHTTPHeaderField: header.key.rawValue)
+      }
+    }
     return HTTPRequest(requester: requester,
                        retryStrategy: retryStrategy,
                        request: request,

Tests/AlgoliaSearchClientTests/Unit/CustomClientConfigurationTests.swift

@@ -0,0 +1,46 @@
+//
+//  CustomClientConfigurationTests.swift
+//
+//
+//  Created by Vladislav Fitc on 27/11/2023.
+//
+
+import Foundation
+
+import Foundation
+import XCTest
+@testable import AlgoliaSearchClient
+
+class CustomClientConfigurationTests: XCTestCase {
+
+  func testCustomHeaders() throws {
+    let configuration = SearchConfiguration(applicationID: "undefined", apiKey: "undefined")
+      .set(\.defaultHeaders, to: ["default-header": "default-header-value"])
+
+    let requester = TestRequester()
+
+    let client = SearchClient(configuration: configuration,
+                              requester: requester)
+
+    let exp = expectation(description: "method call")
+
+    requester.onRequest = { request in
+      let headers = request.allHTTPHeaderFields ?? [:]
+      XCTAssert(headers.contains(where: { $0.key == "default-header" && $0.value == "default-header-value" }))
+      XCTAssert((request.allHTTPHeaderFields ?? [:]).contains(where: { $0.key == "another-header" && $0.value == "another-value" }))
+      exp.fulfill()
+    }
+
+    let queries: [MultiSearchQuery] = [
+      .hitsSearch(.init(indexName: "some-index", query: "search"))
+    ]
+
+    let requestOptions = RequestOptions(headers: ["another-header": "another-value"])
+
+    client.search(queries: queries, requestOptions: requestOptions) { _ in }
+
+    waitForExpectations(timeout: 5)
+
+  }
+
+}