test: add ConfigManager unit tests

Author: objz

core/build.gradle.kts

@@ -26,6 +26,8 @@ dependencies {
 
     compileOnly("org.spongepowered:configurate-yaml:4.2.0")
     compileOnly("org.snakeyaml:snakeyaml-engine:2.10")
+    testImplementation("org.spongepowered:configurate-yaml:4.2.0")
+    testImplementation("org.snakeyaml:snakeyaml-engine:2.10")
     api("org.slf4j:slf4j-api:2.0.17")
     api("io.undertow:undertow-core:2.3.12.Final")
     api("io.undertow:undertow-websockets-jsr:2.3.12.Final")

core/src/test/java/dev/objz/commandbridge/config/ConfigManagerTest.java

@@ -0,0 +1,113 @@
+package dev.objz.commandbridge.config;
+
+import dev.objz.commandbridge.config.model.BackendsConfig;
+import dev.objz.commandbridge.logging.Log;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ConfigManagerTest {
+
+    @BeforeAll
+    static void installLog() {
+        try {
+            Log.install(java.util.logging.Logger.getLogger("config-test"));
+        } catch (IllegalStateException ignored) {
+            // already installed by another test class
+        }
+    }
+
+    @Test
+    void loadCreatesDefaultWhenFileMissing(@TempDir Path tempDir) {
+        var manager = new ConfigManager<>(tempDir, BackendsConfig.class);
+
+        boolean result = manager.load();
+
+        assertTrue(result, "load() should return true for freshly-created defaults");
+        assertTrue(Files.exists(tempDir.resolve("config.yml")), "config.yml should be created");
+        assertNotNull(manager.current(), "current() should not be null after load");
+    }
+
+    @Test
+    void loadReturnsTrueWithValidYaml(@TempDir Path tempDir) throws IOException {
+        Path configFile = tempDir.resolve("config.yml");
+        Files.writeString(configFile, validYaml("lobby-1"));
+
+        var manager = new ConfigManager<>(tempDir, BackendsConfig.class);
+        boolean result = manager.load();
+
+        assertTrue(result, "load() should return true for valid YAML");
+        assertNotNull(manager.current(), "current() should not be null");
+        assertTrue("lobby-1".equals(manager.current().clientId()),
+                "clientId should match written YAML value");
+    }
+
+    @Test
+    void reloadPicksUpChanges(@TempDir Path tempDir) throws IOException {
+        Path configFile = tempDir.resolve("config.yml");
+        Files.writeString(configFile, validYaml("server-a"));
+
+        var manager = new ConfigManager<>(tempDir, BackendsConfig.class);
+        assertTrue(manager.load(), "initial load should succeed");
+        assertTrue("server-a".equals(manager.current().clientId()),
+                "clientId should be server-a after initial load");
+
+        Files.writeString(configFile, validYaml("server-b"));
+        assertTrue(manager.reload(), "reload should succeed");
+        assertTrue("server-b".equals(manager.current().clientId()),
+                "clientId should be server-b after reload");
+    }
+
+    @Test
+    void currentReturnsNullBeforeLoad(@TempDir Path tempDir) {
+        var manager = new ConfigManager<>(tempDir, BackendsConfig.class);
+
+        assertNull(manager.current(), "current() should be null before any load");
+    }
+
+    @Test
+    void loadWithMissingRequiredFieldFallsBackToDefault(@TempDir Path tempDir) throws IOException {
+        Path configFile = tempDir.resolve("config.yml");
+        Files.writeString(configFile, "client-id: partial-server\n");
+
+        var manager = new ConfigManager<>(tempDir, BackendsConfig.class);
+        manager.load();
+
+        assertNotNull(manager.current(), "current() should not be null even with partial YAML");
+        assertNotNull(manager.current().clientId(),
+                "clientId should be populated from partial YAML or defaults");
+    }
+
+    private static String validYaml(String clientId) {
+        return """
+                client-id: "%s"
+                endpoint-type: WEBSOCKET
+                endpoints:
+                  websocket:
+                    host: "127.0.0.1"
+                    port: 8765
+                  redis:
+                    host: "127.0.0.1"
+                    port: 6379
+                    username: ""
+                    password: ""
+                security:
+                  tls-mode: TOFU
+                  tls-pin: ""
+                  secret: "my-real-secret"
+                timeouts:
+                  auth-timeout: 5
+                  reconnect-timeout: 60
+                  reconnect-interval: 5
+                debug: false
+                """.formatted(clientId);
+    }
+}