From 6d289e939d8e317ffd74ea6bfef94ffe6b0734a0 Mon Sep 17 00:00:00 2001
From: Thiago Santos <programadorthi@gmail.com>
Date: Sun, 14 Jan 2024 04:16:59 -0300
Subject: [PATCH] feat: compose pop result support

---
 .../routing/compose/ComposeRoutingExt.kt      | 22 ++++++++++-
 .../compose/ComposeRoutingPopResult.kt        | 11 ++++++
 .../routing/compose/ComposeRoutingTest.kt     | 37 +++++++++++++++++++
 3 files changed, 68 insertions(+), 2 deletions(-)
 create mode 100644 compose/common/src/dev/programadorthi/routing/compose/ComposeRoutingPopResult.kt

diff --git a/compose/common/src/dev/programadorthi/routing/compose/ComposeRoutingExt.kt b/compose/common/src/dev/programadorthi/routing/compose/ComposeRoutingExt.kt
index c9fc493..b0f5aff 100644
--- a/compose/common/src/dev/programadorthi/routing/compose/ComposeRoutingExt.kt
+++ b/compose/common/src/dev/programadorthi/routing/compose/ComposeRoutingExt.kt
@@ -1,10 +1,28 @@
 package dev.programadorthi.routing.compose
 
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.ProvidableCompositionLocal
+import androidx.compose.runtime.staticCompositionLocalOf
 import dev.programadorthi.routing.core.Routing
 
+public val LocalPopResult: ProvidableCompositionLocal<ComposeRoutingPopResult?> =
+    staticCompositionLocalOf { null }
+
 public fun Routing.canPop(): Boolean = contentList.size > 1
 
-public fun Routing.pop() {
+public fun Routing.pop(result: Any? = null) {
     contentList.removeLastOrNull()
-    // TODO: add support to send result
+    if (result == null) return
+
+    val lastIndex = contentList.lastIndex
+    if (lastIndex < 0) return
+
+    val lastContent = contentList[lastIndex]
+    val popResult = ComposeRoutingPopResult(content = result)
+
+    contentList[lastIndex] = {
+        CompositionLocalProvider(LocalPopResult provides popResult) {
+            lastContent()
+        }
+    }
 }
diff --git a/compose/common/src/dev/programadorthi/routing/compose/ComposeRoutingPopResult.kt b/compose/common/src/dev/programadorthi/routing/compose/ComposeRoutingPopResult.kt
new file mode 100644
index 0000000..df692fb
--- /dev/null
+++ b/compose/common/src/dev/programadorthi/routing/compose/ComposeRoutingPopResult.kt
@@ -0,0 +1,11 @@
+package dev.programadorthi.routing.compose
+
+/**
+ * Add support to a previous [androidx.compose.runtime.Composable] get the popped result
+ */
+@Suppress("UNCHECKED_CAST")
+public class ComposeRoutingPopResult internal constructor(
+    internal val content: Any? = null,
+) {
+    public fun <T> result(): T? = content as? T
+}
diff --git a/compose/common/test/dev/programadorthi/routing/compose/ComposeRoutingTest.kt b/compose/common/test/dev/programadorthi/routing/compose/ComposeRoutingTest.kt
index e7bad5c..68b7100 100644
--- a/compose/common/test/dev/programadorthi/routing/compose/ComposeRoutingTest.kt
+++ b/compose/common/test/dev/programadorthi/routing/compose/ComposeRoutingTest.kt
@@ -320,4 +320,41 @@ internal class ComposeRoutingTest {
             // THEN
             assertEquals(3, composedCounter)
         }
+
+    @Test
+    fun shouldPopAComposableWithResult() =
+        runComposeTest { coroutineContext, composition, clock ->
+            // GIVEN
+            var poppedMessage: String? = null
+
+            val routing =
+                routing(parentCoroutineContext = coroutineContext) {
+                    composable(path = "/push") {
+                        poppedMessage = LocalPopResult.current?.result<String>()
+                    }
+                }
+
+            composition.setContent {
+                Routing(
+                    routing = routing,
+                    initial = {},
+                )
+            }
+
+            // WHEN
+            routing.push(path = "/push")
+            advanceTimeBy(99) // Ask for routing
+            clock.sendFrame(0L) // Ask for recomposition
+
+            routing.push(path = "/push")
+            advanceTimeBy(99) // Ask for routing
+            clock.sendFrame(0L) // Ask for recomposition
+
+            routing.pop(result = "This is the popped message")
+            advanceTimeBy(99) // Ask for routing
+            clock.sendFrame(0L) // Ask for recomposition
+
+            // THEN
+            assertEquals("This is the popped message", poppedMessage)
+        }
 }