Bug 1864075 - Create navigation middleware for the debug drawer

app/src/main/java/org/mozilla/fenix/debugsettings/navigation/DebugDrawerDestination.kt

@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.debugsettings.navigation
+
+import androidx.annotation.StringRes
+import androidx.compose.runtime.Composable
+
+/**
+ * A navigation destination for screens within the Debug Drawer.
+ *
+ * @property route The navigation route of the destination.
+ * @property title The string ID of the destination's title.
+ * @property content The destination's [Composable].
+ */
+data class DebugDrawerDestination(
+    val route: String,
+    @StringRes val title: Int,
+    val content: @Composable () -> Unit,
+)

app/src/main/java/org/mozilla/fenix/debugsettings/navigation/DebugDrawerRoute.kt

@@ -0,0 +1,52 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.debugsettings.navigation
+
+import androidx.annotation.StringRes
+import org.mozilla.fenix.R
+import org.mozilla.fenix.debugsettings.ui.DebugDrawerHome
+import org.mozilla.fenix.debugsettings.tabs.TabTools as TabToolsScreen
+
+/**
+ * The navigation routes for screens within the Debug Drawer.
+ *
+ * @property route The navigation route of the destination.
+ * @property title The string ID of the destination's title.
+ */
+enum class DebugDrawerRoute(val route: String, @StringRes val title: Int) {
+    /**
+     * The navigation route for [DebugDrawerHome].
+     */
+    Home(
+        route = "home",
+        title = R.string.debug_drawer_title,
+    ),
+
+    /**
+     * The navigation route for [TabToolsScreen].
+     */
+    TabTools(
+        route = "tab_tools",
+        title = R.string.debug_drawer_tab_tools_title,
+    ),
+}
+
+/**
+ * Creates a list of [DebugDrawerDestination]s for the [DebugDrawerRoute]s in Fenix.
+ */
+fun debugDrawerDestinationsFromRoutes(
+    // Composable content dependencies will go here (e.g. browser store, the list of menu items, etc.)
+): List<DebugDrawerDestination> = DebugDrawerRoute.values().map { debugDrawerRoute ->
+    DebugDrawerDestination(
+        route = debugDrawerRoute.route,
+        title = debugDrawerRoute.title,
+        content = {
+            when (debugDrawerRoute) {
+                DebugDrawerRoute.Home -> {}
+                DebugDrawerRoute.TabTools -> {}
+            }
+        },
+    )
+}

app/src/main/java/org/mozilla/fenix/debugsettings/store/DebugDrawerAction.kt

@@ -5,6 +5,8 @@
 package org.mozilla.fenix.debugsettings.store
 
 import mozilla.components.lib.state.Action
+import org.mozilla.fenix.debugsettings.ui.DebugDrawerHome
+import org.mozilla.fenix.debugsettings.tabs.TabTools as TabToolsScreen
 
 /**
  * [Action] implementation related to [DebugDrawerStore].
@@ -20,4 +22,25 @@ sealed class DebugDrawerAction : Action {
      * [DebugDrawerAction] fired when the user closes the drawer.
      */
     object DrawerClosed : DebugDrawerAction()
+
+    /**
+     * [DebugDrawerAction] fired when a navigation event occurs for a specific destination.
+     */
+    sealed class NavigateTo : DebugDrawerAction() {
+
+        /**
+         * [NavigateTo] action fired when the debug drawer needs to navigate to [DebugDrawerHome].
+         */
+        object Home : NavigateTo()
+
+        /**
+         * [NavigateTo] action fired when the debug drawer needs to navigate to [TabToolsScreen].
+         */
+        object TabTools : NavigateTo()
+    }
+
+    /**
+     * [DebugDrawerAction] fired when a back navigation event occurs.
+     */
+    object OnBackPressed : DebugDrawerAction()
 }

app/src/main/java/org/mozilla/fenix/debugsettings/store/DebugDrawerNavigationMiddleware.kt

@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.debugsettings.store
+
+import androidx.navigation.NavHostController
+import mozilla.components.lib.state.Middleware
+import mozilla.components.lib.state.MiddlewareContext
+import org.mozilla.fenix.debugsettings.navigation.DebugDrawerRoute
+
+/**
+ * Middleware that handles navigation events for the Debug Drawer feature.
+ *
+ * @param navController [NavHostController] used to execute any navigation actions on the UI.
+ */
+class DebugDrawerNavigationMiddleware(
+    private val navController: NavHostController,
+) : Middleware<DebugDrawerState, DebugDrawerAction> {
+
+    override fun invoke(
+        context: MiddlewareContext<DebugDrawerState, DebugDrawerAction>,
+        next: (DebugDrawerAction) -> Unit,
+        action: DebugDrawerAction,
+    ) {
+        when (action) {
+            is DebugDrawerAction.NavigateTo.Home -> navController.navigate(route = DebugDrawerRoute.Home.route)
+            is DebugDrawerAction.NavigateTo.TabTools -> navController.navigate(route = DebugDrawerRoute.TabTools.route)
+            is DebugDrawerAction.OnBackPressed -> navController.popBackStack()
+            is DebugDrawerAction.DrawerOpened, DebugDrawerAction.DrawerClosed -> {} // no-op
+        }
+    }
+}

app/src/main/java/org/mozilla/fenix/debugsettings/store/DebugDrawerStore.kt

@@ -20,9 +20,8 @@ class DebugDrawerStore(
     middlewares,
 )
 
-private fun reduce(state: DebugDrawerState, action: DebugDrawerAction): DebugDrawerState {
-    return when (action) {
-        is DebugDrawerAction.DrawerOpened -> state.copy(drawerStatus = DrawerStatus.Open)
-        is DebugDrawerAction.DrawerClosed -> state.copy(drawerStatus = DrawerStatus.Closed)
-    }
+private fun reduce(state: DebugDrawerState, action: DebugDrawerAction): DebugDrawerState = when (action) {
+    is DebugDrawerAction.DrawerOpened -> state.copy(drawerStatus = DrawerStatus.Open)
+    is DebugDrawerAction.DrawerClosed -> state.copy(drawerStatus = DrawerStatus.Closed)
+    is DebugDrawerAction.NavigateTo, DebugDrawerAction.OnBackPressed -> state // handled by [DebugDrawerNavigationMiddleware]
 }

app/src/main/res/values/strings.xml

@@ -2411,8 +2411,10 @@
     <string name="download_language_file_dialog_negative_button_text">Cancel</string>
 
     <!-- Debug drawer -->
+    <!-- The user-facing title of the Debug Drawer feature. -->
+    <string name="debug_drawer_title">Debug Tools</string>
     <!-- The title of the Tab Tools feature in the Debug Drawer. -->
-    <string name="debug_drawer_tab_tools_title" tools:ignore="UnusedResources">Tab Tools</string>
+    <string name="debug_drawer_tab_tools_title">Tab Tools</string>
     <!-- The title of the tab count section in Tab Tools. -->
     <string name="debug_drawer_tab_tools_tab_count_title">Tab count</string>
     <!-- The active tab count category in the tab count section in Tab Tools. -->

app/src/test/java/org/mozilla/fenix/debugsettings/DebugDrawerNavigationMiddlewareTest.kt

@@ -0,0 +1,63 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.debugsettings
+
+import androidx.navigation.NavHostController
+import io.mockk.called
+import io.mockk.mockk
+import io.mockk.verify
+import mozilla.components.support.test.ext.joinBlocking
+import org.junit.Before
+import org.junit.Test
+import org.mozilla.fenix.debugsettings.navigation.DebugDrawerRoute
+import org.mozilla.fenix.debugsettings.store.DebugDrawerAction
+import org.mozilla.fenix.debugsettings.store.DebugDrawerNavigationMiddleware
+import org.mozilla.fenix.debugsettings.store.DebugDrawerStore
+
+class DebugDrawerNavigationMiddlewareTest {
+
+    private val navController: NavHostController = mockk(relaxed = true)
+    private lateinit var store: DebugDrawerStore
+
+    @Before
+    fun setup() {
+        store = DebugDrawerStore(
+            middlewares = listOf(
+                DebugDrawerNavigationMiddleware(
+                    navController = navController,
+                ),
+            ),
+        )
+    }
+
+    @Test
+    fun `WHEN home is the next destination THEN home is navigated to`() {
+        store.dispatch(DebugDrawerAction.NavigateTo.Home).joinBlocking()
+
+        verify { navController.navigate(DebugDrawerRoute.Home.route) }
+    }
+
+    @Test
+    fun `WHEN the tab tools screen is the next destination THEN the tab tools screen is navigated to`() {
+        store.dispatch(DebugDrawerAction.NavigateTo.TabTools).joinBlocking()
+
+        verify { navController.navigate(DebugDrawerRoute.TabTools.route) }
+    }
+
+    @Test
+    fun `WHEN the back button is pressed THEN the drawer should go back one screen`() {
+        store.dispatch(DebugDrawerAction.OnBackPressed).joinBlocking()
+
+        verify { navController.popBackStack() }
+    }
+
+    @Test
+    fun `WHEN a non-navigation action is dispatched THEN the drawer should not navigate`() {
+        store.dispatch(DebugDrawerAction.DrawerOpened).joinBlocking()
+        store.dispatch(DebugDrawerAction.DrawerClosed).joinBlocking()
+
+        verify { navController wasNot called }
+    }
+}

plugins/fenixdependencies/src/main/java/FenixDependenciesPlugin.kt

@@ -60,6 +60,7 @@ object FenixDependencies {
     const val androidx_navigation_ui = "androidx.navigation:navigation-ui:${FenixVersions.androidx_navigation}"
     const val androidx_transition = "androidx.transition:transition:${FenixVersions.androidx_transition}"
     const val androidx_datastore = "androidx.datastore:datastore:${FenixVersions.androidx_datastore}"
+    const val androidx_compose_navigation = "androidx.navigation:navigation-compose:${FenixVersions.androidx_navigation}"
 
     const val google_accompanist_drawablepainter = "com.google.accompanist:accompanist-drawablepainter:${FenixVersions.google_accompanist}"