UHF-9239: Add tests

tests/modules/helfi_api_client_test/helfi_api_client_test.info.yml

@@ -0,0 +1,6 @@
+name: HELfi api client test
+type: module
+package: Custom
+core_version_requirement: ^9 || ^10
+dependencies:
+  - helfi_api_base

tests/modules/helfi_api_client_test/src/ApiClient.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\helfi_api_client_test;
+
+use Drupal\helfi_api_base\ApiClient\ApiClientBase;
+use Drupal\helfi_api_base\ApiClient\ApiResponse;
+use Drupal\helfi_api_base\ApiClient\CacheValue;
+use GuzzleHttp\Exception\GuzzleException;
+
+/**
+ * Class responsible for performing language negotiation.
+ */
+class ApiClient extends ApiClientBase {
+
+  /**
+   * Expose protected method for testing.
+   *
+   * @throws GuzzleException
+   */
+  public function exposedMakeRequest(string $method, string $url, array $options = [], ?callable $mockCallback = NULL): ApiResponse {
+    return $this->makeRequest($method, $url, $options, $mockCallback);
+  }
+
+  /**
+   * Expose protected method for testing
+   */
+  public function exposedCache(string $key, callable $callback): CacheValue {
+    return $this->cache($key, $callback);
+  }
+
+}