Add test for KeysViewModel state updates (#507)

Added unit tests to `KeysViewModelTest.kt` to cover `setNewKeyName` and `setNewKeyValue` functions. This ensures that the state flow correctly updates when key names and values are modified. This increases the test coverage for UI state manipulation within the Keys settings module.

app/src/test/java/com/m57/hermescontrol/ui/keys/KeysViewModelTest.kt

@@ -0,0 +1,57 @@
+package com.m57.hermescontrol.ui.keys
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.advanceUntilIdle
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.setMain
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+
+@OptIn(ExperimentalCoroutinesApi::class)
+class KeysViewModelTest {
+    private val testDispatcher = StandardTestDispatcher()
+
+    private fun createViewModel(): KeysViewModel {
+        val vm = KeysViewModel()
+        testDispatcher.scheduler.advanceUntilIdle()
+        return vm
+    }
+
+    @Before
+    fun setUp() {
+        Dispatchers.setMain(testDispatcher)
+    }
+
+    @After
+    fun tearDown() {
+        Dispatchers.resetMain()
+    }
+
+    @Test
+    fun `setNewKeyName updates state flow correctly`() {
+        val viewModel = createViewModel()
+
+        assertEquals("", viewModel.uiState.value.newKeyName)
+
+        viewModel.setNewKeyName("MY_NEW_API_KEY")
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        assertEquals("MY_NEW_API_KEY", viewModel.uiState.value.newKeyName)
+    }
+
+    @Test
+    fun `setNewKeyValue updates state flow correctly`() {
+        val viewModel = createViewModel()
+
+        assertEquals("", viewModel.uiState.value.newKeyValue)
+
+        viewModel.setNewKeyValue("dummy_token_value_that_is_long_enough")
+        testDispatcher.scheduler.advanceUntilIdle()
+
+        assertEquals("dummy_token_value_that_is_long_enough", viewModel.uiState.value.newKeyValue)
+    }
+}