add unit tests

app/src/test/java/com/example/hpostesting/CsvWriterTest.kt

@@ -0,0 +1,67 @@
+package com.example.hpostesting
+
+import android.content.Context
+import com.example.hpostesting.data.CsvWriter
+import org.junit.Assert
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+
+@RunWith(RobolectricTestRunner::class)
+@Config(manifest = Config.NONE)
+class CsvWriterTest {
+
+    private lateinit var csvWriter: CsvWriter
+    private lateinit var context: Context
+
+    @Before
+    fun setUp() {
+        context = androidx.test.core.app.ApplicationProvider.getApplicationContext()
+        csvWriter = CsvWriter(context)
+    }
+
+    @Test
+    fun writeCsv_Success() {
+        // Arrange
+        val fileName = "test.csv"
+        val data = listOf(
+            arrayOf("1", "A", "1990", "Positive", "2024-02-04", "image_url1", "John Doe"),
+            arrayOf("2", "B", "1985", "Negative", "2024-02-05", "image_url2", "Jane Doe")
+        )
+
+        // Act
+        val result = csvWriter.writeCsv(fileName, data)
+
+        // Assert
+        Assert.assertTrue(result)
+    }
+
+//    @Test
+//    fun writeCsv_Failure() {
+//        // Arrange
+//        val fileName = "test.csv"
+//        val data = listOf(
+//            arrayOf("1", "A", "1990", "Positive", "2024-02-04", "image_url1", "John Doe"),
+//            arrayOf("2", "B", "1985", "Negative", "2024-02-05", "image_url2", "Jane Doe")
+//        )
+//
+//        // Mocking Environment.getExternalStorageDirectory()
+//        val mockFile = Mockito.mock(File::class.java)
+//        Mockito.`when`(Environment.getExternalStorageDirectory()).thenReturn(mockFile)
+//        Mockito.`when`(mockFile.exists()).thenReturn(true)
+//
+//        // Mocking FileWriter to simulate IOException
+//        val mockWriter = Mockito.mock(FileWriter::class.java)
+//        Mockito.`when`(mockWriter.write(Mockito.anyString())).thenThrow(IOException::class.java)
+//        Mockito.`when`(mockFile.absolutePath).thenReturn("/fake/path/to/file.csv")
+//        Mockito.`when`(FileWriter(mockFile)).thenReturn(mockWriter)
+//
+//        // Act
+//        val result = csvWriter.writeCsv(fileName, data)
+//
+//        // Assert
+//        Assert.assertFalse("Expected writeCsv to fail", result)
+//    }
+}