[fenix] Close https://github.com/mozilla-mobile/fenix/issues/17821: Add TabsTrayStore with actions and reducer (https://github.com/mozilla-mobile/fenix/pull/18773)

app/src/main/java/org/mozilla/fenix/tabstray/TabsTrayStore.kt

@@ -0,0 +1,154 @@
+/* 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.tabstray
+
+import mozilla.components.concept.tabstray.Tab
+import mozilla.components.lib.state.Action
+import mozilla.components.lib.state.State
+import mozilla.components.lib.state.Store
+
+/**
+ * Value type that represents the state of the tabs tray.
+ *
+ * @property selectedPage The current page in the tray can be on.
+ * @property mode Whether the browser tab list is in multi-select mode or not with the set of
+ * currently selected tabs.
+ * @property syncing Whether the Synced Tabs feature should fetch the latest tabs from paired
+ * devices.
+ */
+data class TabsTrayState(
+    val selectedPage: Page = Page.NormalTabs,
+    val mode: Mode = Mode.Normal,
+    val syncing: Boolean = false
+) : State {
+
+    /**
+     * The current mode that the tabs list is in.
+     */
+    sealed class Mode {
+
+        /**
+         * A set of selected tabs which we would want to perform an action on.
+         */
+        open val selectedTabs = emptySet<Tab>()
+
+        /**
+         * The default mode the tabs list is in.
+         */
+        object Normal : Mode()
+
+        /**
+         * The multi-select mode that the tabs list is in containing the set of currently
+         * selected tabs.
+         */
+        data class Select(override val selectedTabs: Set<Tab>) : Mode()
+    }
+}
+
+/**
+ * The different pagers in the tray that we can switch between in the [TrayPagerAdapter].
+ */
+enum class Page {
+
+    /**
+     * The pager position that displays normal tabs.
+     */
+    NormalTabs,
+
+    /**
+     * The pager position that displays private tabs.
+     */
+    PrivateTabs,
+
+    /**
+     * The pager position that displays Synced Tabs.
+     */
+    SyncedTabs
+}
+
+/**
+ * [Action] implementation related to [TabsTrayStore].
+ */
+sealed class TabsTrayAction : Action {
+
+    /**
+     * Entered multi-select mode.
+     */
+    object EnterSelectMode : TabsTrayAction()
+
+    /**
+     * Exited multi-select mode.
+     */
+    object ExitSelectMode : TabsTrayAction()
+
+    /**
+     * Added a new [Tab] to the selection set.
+     */
+    data class AddSelectTab(val tab: Tab) : TabsTrayAction()
+
+    /**
+     * Removed a [Tab] from the selection set.
+     */
+    data class RemoveSelectTab(val tab: Tab) : TabsTrayAction()
+
+    /**
+     * The active page in the tray that is now in focus.
+     */
+    data class PageSelected(val page: Page) : TabsTrayAction()
+
+    /**
+     * A request to perform a "sync" action.
+     */
+    object SyncNow : TabsTrayAction()
+
+    /**
+     * When a "sync" action has completed; this can be triggered immediately after [SyncNow] if
+     * no sync action was able to be performed.
+     */
+    object SyncCompleted : TabsTrayAction()
+}
+
+/**
+ * Reducer for [TabsTrayStore].
+ */
+internal object TabsTrayReducer {
+    fun reduce(state: TabsTrayState, action: TabsTrayAction): TabsTrayState {
+        return when (action) {
+            is TabsTrayAction.EnterSelectMode ->
+                state.copy(mode = TabsTrayState.Mode.Select(emptySet()))
+            is TabsTrayAction.ExitSelectMode ->
+                state.copy(mode = TabsTrayState.Mode.Normal)
+            is TabsTrayAction.AddSelectTab ->
+                state.copy(mode = TabsTrayState.Mode.Select(state.mode.selectedTabs + action.tab))
+            is TabsTrayAction.RemoveSelectTab -> {
+                val selected = state.mode.selectedTabs - action.tab
+                state.copy(
+                    mode = if (selected.isEmpty()) {
+                        TabsTrayState.Mode.Normal
+                    } else {
+                        TabsTrayState.Mode.Select(selected)
+                    }
+                )
+            }
+            is TabsTrayAction.PageSelected ->
+                state.copy(selectedPage = action.page)
+            is TabsTrayAction.SyncNow ->
+                state.copy(syncing = true)
+            is TabsTrayAction.SyncCompleted ->
+                state.copy(syncing = false)
+        }
+    }
+}
+
+/**
+ * A [Store] that holds the [TabsTrayState] for the tabs tray and reduces [TabsTrayAction]s
+ * dispatched to the store.
+ */
+class TabsTrayStore(
+    initialState: TabsTrayState = TabsTrayState()
+) : Store<TabsTrayState, TabsTrayAction>(
+    initialState,
+    TabsTrayReducer::reduce
+)

app/src/main/java/org/mozilla/fenix/tabstray/TrayPagerAdapter.kt

@@ -74,8 +74,8 @@ class TrayPagerAdapter(
     companion object {
         const val TRAY_TABS_COUNT = 3
 
-        const val POSITION_NORMAL_TABS = 0
-        const val POSITION_PRIVATE_TABS = 1
-        const val POSITION_SYNCED_TABS = 2
+        val POSITION_NORMAL_TABS = Page.NormalTabs.ordinal
+        val POSITION_PRIVATE_TABS = Page.PrivateTabs.ordinal
+        val POSITION_SYNCED_TABS = Page.SyncedTabs.ordinal
     }
 }

app/src/test/java/org/mozilla/fenix/tabstray/TabsTrayStoreTest.kt

@@ -0,0 +1,131 @@
+/* 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.tabstray
+
+import mozilla.components.support.test.libstate.ext.waitUntilIdle
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.mozilla.fenix.tabstray.browser.createTab
+
+class TabsTrayStoreTest {
+
+    @Test
+    fun `WHEN entering select mode THEN selected tabs are empty`() {
+        val store = TabsTrayStore()
+
+        store.dispatch(TabsTrayAction.EnterSelectMode)
+
+        store.waitUntilIdle()
+
+        assertTrue(store.state.mode.selectedTabs.isEmpty())
+        assertTrue(store.state.mode is TabsTrayState.Mode.Select)
+
+        store.dispatch(TabsTrayAction.AddSelectTab(createTab()))
+
+        store.dispatch(TabsTrayAction.ExitSelectMode)
+        store.dispatch(TabsTrayAction.EnterSelectMode)
+
+        store.waitUntilIdle()
+
+        assertTrue(store.state.mode.selectedTabs.isEmpty())
+        assertTrue(store.state.mode is TabsTrayState.Mode.Select)
+    }
+
+    @Test
+    fun `WHEN exiting select mode THEN the mode in the state updates`() {
+        val store = TabsTrayStore()
+
+        store.dispatch(TabsTrayAction.EnterSelectMode)
+
+        store.waitUntilIdle()
+
+        assertTrue(store.state.mode is TabsTrayState.Mode.Select)
+
+        store.dispatch(TabsTrayAction.ExitSelectMode)
+
+        store.waitUntilIdle()
+
+        assertTrue(store.state.mode is TabsTrayState.Mode.Normal)
+    }
+
+    @Test
+    fun `WHEN adding a tab to selection THEN it is added to the selectedTabs`() {
+        val store = TabsTrayStore()
+
+        store.dispatch(TabsTrayAction.AddSelectTab(createTab("tab1")))
+
+        store.waitUntilIdle()
+
+        assertEquals("tab1", store.state.mode.selectedTabs.take(1).first().id)
+    }
+
+    @Test
+    fun `WHEN removing a tab THEN it is removed from the selectedTabs`() {
+        val store = TabsTrayStore()
+        val tabForRemoval = createTab("tab1")
+
+        store.dispatch(TabsTrayAction.AddSelectTab(tabForRemoval))
+        store.dispatch(TabsTrayAction.AddSelectTab(createTab("tab2")))
+
+        store.waitUntilIdle()
+
+        assertEquals(2, store.state.mode.selectedTabs.size)
+
+        store.dispatch(TabsTrayAction.RemoveSelectTab(tabForRemoval))
+
+        store.waitUntilIdle()
+
+        assertEquals(1, store.state.mode.selectedTabs.size)
+        assertEquals("tab2", store.state.mode.selectedTabs.take(1).first().id)
+    }
+
+    @Test
+    fun `WHEN store is initialized THEN the default page selected in normal tabs`() {
+        val store = TabsTrayStore()
+
+        assertEquals(Page.NormalTabs, store.state.selectedPage)
+    }
+
+    @Test
+    fun `WHEN page changes THEN the selectedPage is updated`() {
+        val store = TabsTrayStore()
+
+        assertEquals(Page.NormalTabs, store.state.selectedPage)
+
+        store.dispatch(TabsTrayAction.PageSelected(Page.SyncedTabs))
+
+        store.waitUntilIdle()
+
+        assertEquals(Page.SyncedTabs, store.state.selectedPage)
+    }
+
+    @Test
+    fun `WHEN sync now action is triggered THEN update the sync now boolean`() {
+        val store = TabsTrayStore()
+
+        assertFalse(store.state.syncing)
+
+        store.dispatch(TabsTrayAction.SyncNow)
+
+        store.waitUntilIdle()
+
+        assertTrue(store.state.syncing)
+    }
+
+    @Test
+    fun `WHEN sync is complete THEN the syncing boolean is updated`() {
+        val store = TabsTrayStore(initialState = TabsTrayState(syncing = true))
+
+        assertTrue(store.state.syncing)
+
+        store.dispatch(TabsTrayAction.SyncCompleted)
+
+        store.waitUntilIdle()
+
+        assertFalse(store.state.syncing)
+    }
+}

app/src/test/java/org/mozilla/fenix/tabstray/browser/Tab.kt

@@ -0,0 +1,18 @@
+/* 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.tabstray.browser
+
+import mozilla.components.concept.tabstray.Tab
+import java.util.UUID
+
+/**
+ * Helper for writing tests that need a [Tab].
+ */
+fun createTab(
+    tabId: String = UUID.randomUUID().toString()
+) = Tab(
+    tabId,
+    "https://mozilla.org"
+)

app/src/test/java/org/mozilla/fenix/tabstray/browser/TabAdapterIdStorageTest.kt

@@ -4,13 +4,11 @@
 
 package org.mozilla.fenix.tabstray.browser
 
-import mozilla.components.concept.tabstray.Tab
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertNotEquals
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
-import java.util.UUID
 
 @RunWith(FenixRobolectricTestRunner::class)
 class TabAdapterIdStorageTest {
@@ -78,8 +76,3 @@ class TabAdapterIdStorageTest {
         assertNotEquals(id2, id3)
     }
 }
-
-fun createTab() = Tab(
-    UUID.randomUUID().toString(),
-    "https://mozilla.org"
-)