fix(chat): redraw a typing avatar when the typist's profile resolves

ui/components/src/main/kotlin/com/getcode/ui/components/chat/TypingIndicator.kt

@@ -152,6 +152,16 @@ private fun <T> AvatarStack(
         }
     }
 
+    // A typist can change without changing key, such as when their profile resolves after they
+    // started typing. The effect above only runs when the keys change, so without this the avatar
+    // keeps drawing the typist as they first arrived.
+    LaunchedEffect(shown) {
+        shown.forEach { item ->
+            val itemKey = key(item)
+            entries.firstOrNull { it.key == itemKey && !it.leaving }?.item = item
+        }
+    }
+
     // Stacking order: later slots on top, and a leaving avatar beneath everything, so the ones
     // that close the gap slide over it.
     fun StackEntry<T>.z(): Float = if (leaving) -1f else slot.value

ui/components/src/test/kotlin/com/getcode/ui/components/chat/TypingIndicatorTest.kt

@@ -0,0 +1,45 @@
+package com.getcode.ui.components.chat
+
+import androidx.compose.material.Text
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.test.onNodeWithText
+import com.getcode.theme.DesignSystem
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class TypingIndicatorTest {
+
+    @get:Rule
+    val composeTestRule = createComposeRule()
+
+    private data class Typist(val id: String, val name: String?)
+
+    // A typist can appear before their profile resolves, and the resolved profile arrives as the
+    // same typist (same key) with more to draw. The avatar has to pick that up.
+    @Test
+    fun avatarRedrawsWhenATypistChangesUnderTheSameKey() {
+        var typists by mutableStateOf(listOf(Typist("a", name = null)))
+        composeTestRule.setContent {
+            DesignSystem {
+                TypingIndicator(
+                    typists = typists,
+                    key = { it.id },
+                    avatar = { Text(it.name ?: "fallback") },
+                )
+            }
+        }
+        composeTestRule.onNodeWithText("fallback").assertExists()
+
+        typists = listOf(Typist("a", name = "Alice"))
+        composeTestRule.waitForIdle()
+
+        composeTestRule.onNodeWithText("Alice").assertExists()
+        composeTestRule.onNodeWithText("fallback").assertDoesNotExist()
+    }
+}