Fix regV5 SMS auto-fill and paste.

feature/registration/src/main/java/org/signal/registration/screens/verificationcode/VerificationCodeScreen.kt

@@ -89,9 +89,7 @@ fun VerificationCodeScreen(
     val code = state.autoFillCode ?: return@LaunchedEffect
 
     if (code.length == VerificationCodeState.CODE_LENGTH && code.all { it.isDigit() } && !state.isSubmittingCode) {
-      code.forEachIndexed { index, digit ->
-        onEvent(VerificationCodeScreenEvents.DigitChanged(index, digit.toString()))
-      }
+      onEvent(VerificationCodeScreenEvents.DigitChanged(0, code))
     }
     onEvent(VerificationCodeScreenEvents.ConsumeAutoFillCode)
   }

feature/registration/src/main/java/org/signal/registration/screens/verificationcode/VerificationCodeScreenEvents.kt

@@ -15,7 +15,8 @@ sealed class VerificationCodeScreenEvents {
   /**
    * The raw [value] of the digit field at [index] changed. The view model interprets it: a single digit is recorded
    * (submitting once the full code is present), an empty [value] is a backspace (deleting a digit and shifting the
-   * following ones left), and multi-character input (e.g. a pasted "123-456") is treated as a pasted code.
+   * following ones left), and multi-character input (e.g. a pasted "123-456" or an auto-filled SMS code) populates
+   * every field at once and submits.
    */
   data class DigitChanged(val index: Int, val value: String) : VerificationCodeScreenEvents() {
     override fun toString(): String = "DigitChanged(index=$index)"

feature/registration/src/main/java/org/signal/registration/screens/verificationcode/VerificationCodeViewModel.kt

@@ -191,7 +191,8 @@ class VerificationCodeViewModel(
    *
    * - an empty [value] is a backspace, deleting a digit and moving focus back
    * - a single digit is recorded and focus advances, submitting once the full code is present
-   * - multi-character input (e.g. a pasted "123-456") is treated as a pasted code
+   * - multi-character input (e.g. a pasted "123-456" or an auto-filled SMS code) populates every field at once and
+   *   submits, all in this single reducer pass
    */
   private suspend fun applyDigitChanged(
     state: VerificationCodeState,
@@ -225,7 +226,33 @@ class VerificationCodeViewModel(
         }
       }
 
-      else -> applyPastedCode(state, remainder)
+      else -> applyFullCode(state, addedDigits, stateEmitter)
+    }
+  }
+
+  /**
+   * Populates every digit field from a full pasted or auto-filled [code] in a single reducer pass and submits it.
+   * Multi-character input that isn't a complete code is ignored.
+   */
+  private suspend fun applyFullCode(
+    state: VerificationCodeState,
+    code: String,
+    stateEmitter: (VerificationCodeState) -> Unit
+  ): VerificationCodeState {
+    if (code.length != CODE_LENGTH) {
+      Log.w(TAG, "[DigitChanged] Ignoring multi-character input containing ${code.length} digits.")
+      return state
+    }
+
+    val updated = state.copy(
+      digits = code.map { it.toString() },
+      focusedDigitIndex = CODE_LENGTH - 1
+    )
+
+    return if (!updated.isSubmittingCode) {
+      submitCode(updated, updated.code, stateEmitter)
+    } else {
+      updated
     }
   }
 
@@ -257,20 +284,6 @@ class VerificationCodeViewModel(
     return applyCodeEntered(state, code).copy(isSubmittingCode = false)
   }
 
-  /**
-   * Strips any formatting (e.g. a hyphen) from pasted text and, if what remains is a full code, populates the fields
-   * by reusing the [VerificationCodeState.autoFillCode] path. Pasted text that doesn't contain a full code is ignored.
-   */
-  private fun applyPastedCode(state: VerificationCodeState, rawCode: String): VerificationCodeState {
-    val digits = rawCode.filter { it.isDigit() }
-    if (digits.length != CODE_LENGTH) {
-      Log.w(TAG, "[DigitChanged] Ignoring pasted text containing ${digits.length} digits.")
-      return state
-    }
-
-    return state.copy(autoFillCode = digits)
-  }
-
   private suspend fun applyCodeEntered(inputState: VerificationCodeState, code: String): VerificationCodeState {
     var state = inputState
     var sessionMetadata = state.sessionMetadata ?: return state.also {

feature/registration/src/test/java/org/signal/registration/screens/verificationcode/VerificationCodeScreenTest.kt

@@ -216,7 +216,7 @@ class VerificationCodeScreenTest {
   }
 
   @Test
-  fun `autoFillCode emits a DigitChanged for each digit`() {
+  fun `autoFillCode emits a single DigitChanged with the full code`() {
     // Given
     val emittedEvents = mutableListOf<VerificationCodeScreenEvents>()
 
@@ -231,13 +231,13 @@ class VerificationCodeScreenTest {
 
     // When - the auto-fill effect populates the fields
     composeTestRule.waitUntil(timeoutMillis = 5_000) {
-      emittedEvents.filterIsInstance<VerificationCodeScreenEvents.DigitChanged>().size == 6
+      emittedEvents.any { it is VerificationCodeScreenEvents.DigitChanged }
     }
 
-    // Then
+    // Then - a single event carries the whole code, rather than a burst of per-digit events
     val digitChanges = emittedEvents.filterIsInstance<VerificationCodeScreenEvents.DigitChanged>()
-    assert(digitChanges == (0 until 6).map { VerificationCodeScreenEvents.DigitChanged(it, "${it + 1}") }) {
-      "Expected a DigitChanged per digit but got $digitChanges"
+    assert(digitChanges == listOf(VerificationCodeScreenEvents.DigitChanged(0, "123456"))) {
+      "Expected a single DigitChanged(0, 123456) but got $digitChanges"
     }
   }
 

feature/registration/src/test/java/org/signal/registration/screens/verificationcode/VerificationCodeViewModelTest.kt

@@ -197,8 +197,17 @@ class VerificationCodeViewModelTest {
   }
 
   @Test
-  fun `DigitChanged with pasted hyphenated text stores the stripped code in autoFillCode`() = runTest {
-    val initialState = VerificationCodeState()
+  fun `DigitChanged with pasted hyphenated text populates all digits and submits`() = runTest {
+    val sessionMetadata = createSessionMetadata()
+    val initialState = VerificationCodeState(
+      sessionMetadata = sessionMetadata,
+      e164 = "+15551234567"
+    )
+
+    coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
+      RequestResult.NonSuccess(
+        NetworkController.SubmitVerificationCodeError.InvalidSessionIdOrVerificationCode("Wrong code")
+      )
 
     viewModel.applyEvent(
       initialState,
@@ -206,12 +215,23 @@ class VerificationCodeViewModelTest {
       stateEmitter
     )
 
-    assertThat(emittedStates.last().autoFillCode).isEqualTo("123456")
+    coVerify { mockRepository.submitVerificationCode(sessionMetadata.id, "123456") }
+    assertThat(emittedStates.first().digits).isEqualTo(listOf("1", "2", "3", "4", "5", "6"))
+    assertThat(emittedStates.first().isSubmittingCode).isTrue()
   }
 
   @Test
-  fun `DigitChanged with a pasted plain code stores it in autoFillCode`() = runTest {
-    val initialState = VerificationCodeState()
+  fun `DigitChanged with a pasted plain code populates all digits and submits`() = runTest {
+    val sessionMetadata = createSessionMetadata()
+    val initialState = VerificationCodeState(
+      sessionMetadata = sessionMetadata,
+      e164 = "+15551234567"
+    )
+
+    coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
+      RequestResult.NonSuccess(
+        NetworkController.SubmitVerificationCodeError.InvalidSessionIdOrVerificationCode("Wrong code")
+      )
 
     viewModel.applyEvent(
       initialState,
@@ -219,12 +239,17 @@ class VerificationCodeViewModelTest {
       stateEmitter
     )
 
-    assertThat(emittedStates.last().autoFillCode).isEqualTo("123456")
+    coVerify { mockRepository.submitVerificationCode(sessionMetadata.id, "123456") }
+    assertThat(emittedStates.first().digits).isEqualTo(listOf("1", "2", "3", "4", "5", "6"))
+    assertThat(emittedStates.first().isSubmittingCode).isTrue()
   }
 
   @Test
   fun `DigitChanged with pasted text of the wrong length is ignored`() = runTest {
-    val initialState = VerificationCodeState()
+    val initialState = VerificationCodeState(
+      sessionMetadata = createSessionMetadata(),
+      e164 = "+15551234567"
+    )
 
     viewModel.applyEvent(
       initialState,
@@ -232,7 +257,8 @@ class VerificationCodeViewModelTest {
       stateEmitter
     )
 
-    assertThat(emittedStates.last().autoFillCode).isNull()
+    coVerify(exactly = 0) { mockRepository.submitVerificationCode(any(), any()) }
+    assertThat(emittedStates.last().digits).isEqualTo(listOf("", "", "", "", "", ""))
   }
 
   @Test
@@ -262,6 +288,28 @@ class VerificationCodeViewModelTest {
     assertThat(vm.state.value.autoFillCode).isEqualTo("123456")
   }
 
+  @Test
+  fun `DigitChanged with a full code dispatched through the event channel submits it in a single pass`() = runTest(testDispatcher) {
+    val sessionMetadata = createSessionMetadata()
+    parentState.value = RegistrationFlowState(
+      sessionMetadata = sessionMetadata,
+      sessionE164 = "+15551234567"
+    )
+
+    coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
+      RequestResult.NonSuccess(
+        NetworkController.SubmitVerificationCodeError.InvalidSessionIdOrVerificationCode("Wrong code")
+      )
+
+    backgroundScope.launch { viewModel.state.collect {} }
+    advanceUntilIdle()
+
+    viewModel.onEvent(VerificationCodeScreenEvents.DigitChanged(0, "123456"))
+    advanceUntilIdle()
+
+    coVerify { mockRepository.submitVerificationCode(sessionMetadata.id, "123456") }
+  }
+
   // ==================== applyEvent: DigitChanged Tests ====================
 
   @Test