Add tests for ApiState error handling

app/src/test/java/com/samad_talukder/mvvmcompose/utils/ApiStateTest.kt

@@ -0,0 +1,93 @@
+package com.samad_talukder.mvvmcompose.utils
+
+import kotlinx.coroutines.runBlocking
+import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.Protocol
+import okhttp3.Request
+import okhttp3.ResponseBody.Companion.toResponseBody
+import okio.IOException
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import retrofit2.Response
+import java.net.SocketTimeoutException
+
+class ApiStateTest {
+
+    @Test
+    fun `safeApiCall returns success when response is successful`() = runBlocking {
+        val result = safeApiCall { Response.success("data") }
+
+        assertTrue(result is ApiState.Success)
+        assertEquals("data", (result as ApiState.Success).data)
+    }
+
+    @Test
+    fun `safeApiCall maps 404 to User Not Found`() = runBlocking {
+        val errorResponse = Response.error<String>(
+            404,
+            "Not Found".toResponseBody("text/plain".toMediaType())
+        )
+
+        val result = safeApiCall { errorResponse }
+
+        assertTrue(result is ApiState.Error)
+        val error = result as ApiState.Error
+        assertEquals("User Not Found", error.message)
+        assertEquals(404, error.code)
+    }
+
+    @Test
+    fun `safeApiCall maps 500 to internal server error`() = runBlocking {
+        val errorResponse = Response.error<String>(
+            500,
+            "Server Error".toResponseBody("text/plain".toMediaType())
+        )
+
+        val result = safeApiCall { errorResponse }
+
+        assertTrue(result is ApiState.Error)
+        val error = result as ApiState.Error
+        assertEquals(
+            "Internal server error. Please try again later.",
+            error.message
+        )
+        assertEquals(500, error.code)
+    }
+
+    @Test
+    fun `safeApiCall maps unknown codes to default error`() = runBlocking {
+        val errorBody = "Bad Request".toResponseBody("text/plain".toMediaType())
+        val rawResponse = okhttp3.Response.Builder()
+            .code(400)
+            .message("Bad Request")
+            .protocol(Protocol.HTTP_1_1)
+            .request(Request.Builder().url("http://localhost/").build())
+            .build()
+        val errorResponse = Response.error<String>(errorBody, rawResponse)
+
+        val result = safeApiCall { errorResponse }
+
+        assertTrue(result is ApiState.Error)
+        val error = result as ApiState.Error
+        assertEquals("Error: 400 Bad Request", error.message)
+        assertEquals(400, error.code)
+    }
+
+    @Test
+    fun `safeApiCall maps IOException to ApiState Error`() = runBlocking {
+        val result = safeApiCall<String> { throw IOException("No Internet") }
+
+        assertTrue(result is ApiState.Error)
+        assertEquals("No Internet", (result as ApiState.Error).message)
+    }
+
+    @Test
+    fun `safeApiCall maps SocketTimeoutException to ApiState Error`() = runBlocking {
+        val result = safeApiCall<String> { throw SocketTimeoutException("Timeout") }
+
+        assertTrue(result is ApiState.Error)
+        assertEquals("Timeout", (result as ApiState.Error).message)
+    }
+}
+