Add unit tests for data-modifying methods

Author: DoomsCoder

AnkiDroid/src/main/java/com/ichi2/anki/provider/CardContentProvider.kt

@@ -754,8 +754,7 @@ class CardContentProvider : ContentProvider() {
         val deletedCount =
             when (sUriMatcher.match(uri)) {
                 NOTES_ID -> {
-                    col.removeNotes(noteIds = listOf(uri.pathSegments[1].toLong()))
-                    1
+                    col.removeNotes(noteIds = listOf(uri.pathSegments[1].toLong())).count
                 }
                 NOTE_TYPES_ID_EMPTY_CARDS -> {
                     val noteType = col.notetypes.get(getNoteTypeIdFromUri(uri, col)) ?: return -1

AnkiDroid/src/test/java/com/ichi2/anki/provider/CardContentProviderTest.kt

@@ -0,0 +1,140 @@
+// SPDX-FileCopyrightText: 2026 Vedant Kakade <vedantkakade05@gmail.com>
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package com.ichi2.anki.provider
+
+import android.content.ContentValues
+import android.net.Uri
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.ichi2.anki.FlashCardsContract
+import com.ichi2.anki.RobolectricTest
+import com.ichi2.testutils.grantPermissions
+import com.ichi2.testutils.subscriberChangeCounter
+import org.hamcrest.MatcherAssert.assertThat
+import org.hamcrest.Matchers.equalTo
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class CardContentProviderTest : RobolectricTest() {
+    @Before
+    override fun setUp() {
+        super.setUp()
+
+        grantPermissions(FlashCardsContract.READ_WRITE_PERMISSION)
+    }
+
+    @Test
+    fun `insert notifies UI`() {
+        val counter = subscriberChangeCounter()
+        val mid = col.notetypes.all()[0].id
+
+        val noteType = col.notetypes.get(mid)!!
+        val fieldCount = noteType.fields.length()
+        val emptyFields = Array(fieldCount) { "" }.joinToString(separator = "\u001f")
+
+        val values =
+            ContentValues().apply {
+                put(FlashCardsContract.Note.MID, mid)
+                put(FlashCardsContract.Note.FLDS, emptyFields)
+            }
+
+        targetContext.contentResolver.insert(FlashCardsContract.Note.CONTENT_URI, values)
+
+        advanceRobolectricLooper()
+        assertThat("Insert should notify UI", counter.hasChanges, equalTo(true))
+    }
+
+    @Test
+    fun `update notifies UI`() {
+        val note = addBasicNote("f1", "b1")
+        val counter = subscriberChangeCounter()
+        val values =
+            ContentValues().apply {
+                put(FlashCardsContract.Note.TAGS, "new_tag")
+            }
+
+        val uri = Uri.withAppendedPath(FlashCardsContract.Note.CONTENT_URI, note.id.toString())
+
+        targetContext.contentResolver.update(uri, values, null, null)
+
+        advanceRobolectricLooper()
+        assertThat("Update should notify UI", counter.hasChanges, equalTo(true))
+    }
+
+    @Test
+    fun `update non-existent note does not notify UI`() {
+        val counter = subscriberChangeCounter()
+        val values =
+            ContentValues().apply {
+                put(FlashCardsContract.Note.TAGS, "new_tag")
+            }
+        val uri = Uri.withAppendedPath(FlashCardsContract.Note.CONTENT_URI, "999999")
+
+        try {
+            targetContext.contentResolver.update(uri, values, null, null)
+        } catch (e: Exception) {
+            // BackendNotException is expected
+        }
+
+        advanceRobolectricLooper()
+        assertThat("Update should not notify UI if update is failed", counter.hasChanges, equalTo(false))
+    }
+
+    @Test
+    fun `delete notifies UI`() {
+        val note = addBasicNote("f1", "b1")
+        val counter = subscriberChangeCounter()
+
+        val uri = Uri.withAppendedPath(FlashCardsContract.Note.CONTENT_URI, note.id.toString())
+
+        targetContext.contentResolver.delete(uri, null, null)
+
+        advanceRobolectricLooper()
+        assertThat("Delete should notify UI", counter.hasChanges, equalTo(true))
+    }
+
+    @Test
+    fun `delete non-existent note does not notify UI`() {
+        val counter = subscriberChangeCounter()
+        val uri = Uri.withAppendedPath(FlashCardsContract.Note.CONTENT_URI, "999999")
+
+        targetContext.contentResolver.delete(uri, null, null)
+
+        advanceRobolectricLooper()
+        assertThat("Delete should not notify UI if nothing was deleted", counter.hasChanges, equalTo(false))
+    }
+
+    @Test
+    fun `bulkInsert notifies UI`() {
+        val counter = subscriberChangeCounter()
+        val mid = col.notetypes.all()[0].id
+
+        val noteType = col.notetypes.get(mid)!!
+        val fieldCount = noteType.fields.length()
+        val emptyFields = Array(fieldCount) { "" }.joinToString(separator = "\u001f")
+
+        val values =
+            arrayOf(
+                ContentValues().apply {
+                    put(FlashCardsContract.Note.MID, mid)
+                    put(FlashCardsContract.Note.FLDS, emptyFields)
+                },
+            )
+
+        targetContext.contentResolver.bulkInsert(FlashCardsContract.Note.CONTENT_URI, values)
+
+        advanceRobolectricLooper()
+        assertThat(" Bulk insert should notify UI", counter.hasChanges, equalTo(true))
+    }
+
+    @Test
+    fun `bulkInsert with empty list does not notify UI`() {
+        val counter = subscriberChangeCounter()
+
+        targetContext.contentResolver.bulkInsert(FlashCardsContract.Note.CONTENT_URI, emptyArray())
+
+        assertThat("Empty bulk insert should not notify UI", counter.hasChanges, equalTo(false))
+    }
+}