From 409cc8f39d6b5cc1c111a62821724fa1393a8510 Mon Sep 17 00:00:00 2001
From: Oleksandr Karpovich <a.n.karpovich@gmail.com>
Date: Thu, 17 Nov 2022 14:09:15 +0100
Subject: [PATCH] Fix Ctrl+Backspace in TextField (#329)

Issue https://github.com/JetBrains/compose-jb/issues/2466

Co-Authored-By: Silas <s.develop@4-dc.de>

Co-authored-by: Silas <s.develop@4-dc.de>
---
 .../text/selection/TextPreparedSelection.kt   |  3 +-
 .../text/selection/SelectionTests.kt          | 56 +++++++++++++++++++
 2 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/selection/TextPreparedSelection.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/selection/TextPreparedSelection.kt
index 363688d6bebc7..1ff4d2a691f2f 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/selection/TextPreparedSelection.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/selection/TextPreparedSelection.kt
@@ -344,6 +344,7 @@ internal abstract class BaseTextPreparedSelection<T : BaseTextPreparedSelection<
 
     private fun charOffset(offset: Int) =
         offset.coerceAtMost(text.length - 1)
+            .coerceAtLeast(0)
 
     private fun getParagraphStart() = text.findParagraphStart(selection.min)
 
@@ -429,4 +430,4 @@ internal class TextFieldPreparedSelection(
             value.getOffsetForPosition(Offset(x, y))
         )
     }
-}
\ No newline at end of file
+}
diff --git a/compose/foundation/foundation/src/desktopTest/kotlin/androidx/compose/foundation/text/selection/SelectionTests.kt b/compose/foundation/foundation/src/desktopTest/kotlin/androidx/compose/foundation/text/selection/SelectionTests.kt
index d328ff0b29a3f..0133d62f5a484 100644
--- a/compose/foundation/foundation/src/desktopTest/kotlin/androidx/compose/foundation/text/selection/SelectionTests.kt
+++ b/compose/foundation/foundation/src/desktopTest/kotlin/androidx/compose/foundation/text/selection/SelectionTests.kt
@@ -153,4 +153,60 @@ class SelectionTests {
         rule.awaitIdle()
         Truth.assertThat(state.value.selection).isEqualTo(TextRange(1, 0))
     }
+
+    @OptIn(ExperimentalTestApi::class, ExperimentalComposeUiApi::class)
+    @Test
+    fun `Ctrl + Backspace on an empty line with DesktopPlatform-Windows`() = runBlocking {
+        setPlatformDefaultKeyMapping(createPlatformDefaultKeyMapping(DesktopPlatform.Windows))
+        val state = mutableStateOf(TextFieldValue(""))
+
+        rule.setContent {
+            BasicTextField(
+                value = state.value,
+                onValueChange = { state.value = it },
+                modifier = Modifier.testTag("textField")
+            )
+        }
+        rule.awaitIdle()
+        rule.onNodeWithTag("textField").performMouseInput {
+            click(Offset(0f, 0f))
+        }
+        rule.awaitIdle()
+        rule.onNodeWithTag("textField").assertIsFocused()
+        Truth.assertThat(state.value.selection).isEqualTo(TextRange(0, 0))
+
+        rule.onNodeWithTag("textField").performKeyInput {
+            keyDown(Key.CtrlLeft)
+            keyDown(Key.Backspace)
+        }
+        rule.awaitIdle()
+    }
+
+    @OptIn(ExperimentalTestApi::class, ExperimentalComposeUiApi::class)
+    @Test
+    fun `Ctrl + Backspace on an empty line with DesktopPlatform-Macos`() = runBlocking {
+        setPlatformDefaultKeyMapping(createPlatformDefaultKeyMapping(DesktopPlatform.MacOS))
+        val state = mutableStateOf(TextFieldValue(""))
+
+        rule.setContent {
+            BasicTextField(
+                value = state.value,
+                onValueChange = { state.value = it },
+                modifier = Modifier.testTag("textField")
+            )
+        }
+        rule.awaitIdle()
+        rule.onNodeWithTag("textField").performMouseInput {
+            click(Offset(0f, 0f))
+        }
+        rule.awaitIdle()
+        rule.onNodeWithTag("textField").assertIsFocused()
+        Truth.assertThat(state.value.selection).isEqualTo(TextRange(0, 0))
+
+        rule.onNodeWithTag("textField").performKeyInput {
+            keyDown(Key.AltLeft)
+            keyDown(Key.Backspace)
+        }
+        rule.awaitIdle()
+    }
 }