Add unit tests for findUniqueFileName

app/src/main/java/fr/free/nrw/commons/upload/worker/UploadWorker.kt

@@ -73,7 +73,7 @@ class UploadWorker(
     lateinit var uploadClient: UploadClient
 
     @Inject
-    lateinit var mediaClient: MediaClient
+    internal lateinit var mediaClient: MediaClient
 
     @Inject
     lateinit var fileUtilsWrapper: FileUtilsWrapper
@@ -562,7 +562,7 @@ class UploadWorker(
         }
     }
 
-    private fun findUniqueFileName(fileName: String): String {
+    internal fun findUniqueFileName(fileName: String): String {
         var sequenceFileName: String? = fileName
         val random = Random()
 
@@ -575,22 +575,22 @@ class UploadWorker(
                     ),
                 ).blockingGet()) {
 
-            // Generate a random 5-character alphanumeric string
-            val randomHash = (random.nextInt(90000) + 10000).toString()
+            // Generate a random 3-character alphanumeric string
+            val randomHash = (random.nextInt(900) + 100).toString()
 
             sequenceFileName =
                 if (fileName.indexOf('.') == -1) {
                     // Append the random hash in parentheses if no file extension is present
-                    "$fileName ($randomHash)"
+                    "$fileName #$randomHash"
                 } else {
                     val regex =
                         Pattern.compile("^(.*)(\\..+?)$")
                     val regexMatcher = regex.matcher(fileName)
                     // Append the random hash in parentheses before the file extension
                     if (regexMatcher.find()) {
-                        "${regexMatcher.group(1)} ($randomHash)${regexMatcher.group(2)}"
+                        "${regexMatcher.group(1)} #$randomHash${regexMatcher.group(2)}"
                     } else {
-                        "$fileName ($randomHash)"
+                    "$fileName #$randomHash"
                     }
                 }
         }

app/src/test/kotlin/fr/free/nrw/commons/upload/worker/UploadWorkerTest.kt

@@ -0,0 +1,68 @@
+import com.nhaarman.mockitokotlin2.*
+import fr.free.nrw.commons.media.MediaClient
+import io.reactivex.Single
+import org.junit.Assert.assertEquals
+import org.junit.Before
+import org.junit.Test
+import org.mockito.Mock
+import org.mockito.MockitoAnnotations
+import fr.free.nrw.commons.upload.worker.UploadWorker
+
+class UploadWorkerTest {
+
+    @Mock
+    lateinit var mediaClient: MediaClient
+
+    @Mock
+    lateinit var context: android.content.Context
+
+    private lateinit var uploadWorker: UploadWorker
+
+    @Before
+    fun setUp() {
+        MockitoAnnotations.openMocks(this)
+        uploadWorker = mock<UploadWorker>()
+        uploadWorker.mediaClient = mediaClient
+        whenever(uploadWorker.mediaClient).thenReturn(mediaClient)
+        whenever(uploadWorker.findUniqueFileName(any())).thenCallRealMethod()
+    }
+
+    @Test
+    fun `findUniqueFileName returns original when file does not exist`() {
+        val fileName = "test_image.jpg"
+        whenever(mediaClient.checkPageExistsUsingTitle("File:$fileName"))
+            .thenReturn(Single.just(false))
+
+        val result = uploadWorker.findUniqueFileName(fileName)
+
+        assertEquals(fileName, result)
+    }
+
+    @Test
+    fun `findUniqueFileName appends hash when file exists`() {
+        val fileName = "test_image.jpg"
+        //mockking: first check exists, second check unique
+        whenever(mediaClient.checkPageExistsUsingTitle(any()))
+            .thenReturn(Single.just(true))
+            .thenReturn(Single.just(false))
+
+        val result = uploadWorker.findUniqueFileName(fileName)
+
+        //verify it follows the #XXX pattern
+        val regex = Regex("test_image #\\d{3}\\.jpg")
+        assert(result.matches(regex))
+    }
+
+    @Test
+    fun `findUniqueFileName handles files without extensions`() {
+        val fileName = "no_extension"
+        whenever(mediaClient.checkPageExistsUsingTitle(any()))
+            .thenReturn(Single.just(true))
+            .thenReturn(Single.just(false))
+
+        val result = uploadWorker.findUniqueFileName(fileName)
+
+        val regex = Regex("no_extension #\\d{3}")
+        assert(result.matches(regex))
+    }
+}