Add multi-group clear API (#70)

Author: yigitozgumus

app/src/test/java/com/trendyol/medusa/DestinationListenerTest.kt

@@ -281,6 +281,48 @@ class DestinationListenerTest {
         }
     }
 
+    @Test
+    fun `given fragments from multiple groups, when clearGroups is called, then matching groups are removed atomically`() {
+        val testObserver = TestObserver<Fragment>()
+        launchActivity<MainActivity>().use { scenario ->
+            scenario.moveToState(Lifecycle.State.RESUMED)
+            scenario.onActivity { activity ->
+                activity.multipleStackNavigator.observeDestinationChanges(activity, testObserver)
+                activity.doAndExecuteFragmentTransactions {
+                    start(FragmentGenerator.generateNewFragment())
+                    start(FragmentGenerator.generateNewFragment(), "group-1")
+                    start(FragmentGenerator.generateNewFragment(), "group-2")
+                    start(FragmentGenerator.generateNewFragment(), "group-1")
+                    start(FragmentGenerator.generateNewFragment(), "group-3")
+                }
+                activity.doAndExecuteFragmentTransactions {
+                    clearGroups("group-1", "group-3")
+                }
+
+                Assert.assertEquals(
+                    "fragment 6",
+                    testObserver.getLastFragmentName(indexFromLast = 1)
+                )
+                Assert.assertEquals(
+                    "fragment 4",
+                    testObserver.getLastFragmentName(indexFromLast = 0)
+                )
+            }
+        }
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun `given default group, when clearGroups is called, then exception is thrown`() {
+        launchActivity<MainActivity>().use { scenario ->
+            scenario.moveToState(Lifecycle.State.RESUMED)
+            scenario.onActivity { activity ->
+                activity.doAndExecuteFragmentTransactions {
+                    clearGroups("group-name", "")
+                }
+            }
+        }
+    }
+
     /**
      * Gets the fragment name at a specific index from the last observed fragment.
      * Useful for testing fragment navigation sequences.

medusa/src/main/java/com/trendyol/medusalib/navigator/FragmentStackState.kt

@@ -73,6 +73,10 @@ data class FragmentStackState constructor(
     }
 
     fun popItems(groupName: String): List<StackItem> {
+        return popItems(setOf(groupName))
+    }
+
+    fun popItems(groupNames: Set<String>): List<StackItem> {
         val currentTabIndex = getSelectedTabIndex()
         val currentTabStack = fragmentTagStack.get(getSelectedTabIndex())
 
@@ -83,7 +87,7 @@ data class FragmentStackState constructor(
 
         for (i in 1 until currentTabStack.size) {
             val stackItem = currentTabStack[i]
-            if (groupName == stackItem.groupName) {
+            if (groupNames.contains(stackItem.groupName)) {
                 deletedStackItems.add(stackItem)
             } else {
                 updatedTabStack.push(stackItem)

medusa/src/main/java/com/trendyol/medusalib/navigator/MultipleStackNavigator.kt

@@ -206,13 +206,17 @@ open class MultipleStackNavigator(
     }
 
     override fun clearGroup(fragmentGroupName: String) {
-        if (fragmentGroupName == DEFAULT_GROUP_NAME) {
+        clearGroups(fragmentGroupName)
+    }
+
+    override fun clearGroups(vararg fragmentGroupNames: String) {
+        if (fragmentGroupNames.any { it == DEFAULT_GROUP_NAME }) {
             throw IllegalArgumentException("Fragment group name can not be empty.")
         }
         val upperFragmentTag = fragmentStackState.peekItemFromSelectedTab()?.fragmentTag
 
         val poppedFragmentTags = fragmentStackState
-            .popItems(fragmentGroupName)
+            .popItems(fragmentGroupNames.toSet())
             .map { it.fragmentTag }
 
         if (poppedFragmentTags.isNotEmpty()) {

medusa/src/main/java/com/trendyol/medusalib/navigator/Navigator.kt

@@ -163,6 +163,13 @@ interface Navigator {
      */
     fun clearGroup(fragmentGroupName: String)
 
+    /**
+     * Clears all fragments with any of the given group names in the
+     * current tab in a single transaction. This method aims to clear all
+     * related/steps fragments from tab atomically.
+     */
+    fun clearGroups(vararg fragmentGroupNames: String)
+
     /**
      * Checks if stack has only root
      * @param tabIndex

medusa/src/test/java/com/trendyol/medusalib/navigator/FragmentStackStateTest.kt

@@ -28,4 +28,30 @@ class FragmentStackStateTest {
 
         Truth.assertThat(stackState.fragmentTagStack).containsExactlyElementsIn(emptyStack)
     }
+
+    @Test
+    fun `popItems removes all items matching given group names from selected tab`() {
+        val stackState = buildFragmentStackState(
+            buildTabStack(0),
+            buildStack(
+                StackItem("ROOT"),
+                StackItem("TAG1", "GROUP_1"),
+                StackItem("TAG2", "GROUP_2"),
+                StackItem("TAG3", "GROUP_1"),
+                StackItem("TAG4", "GROUP_3"),
+            ),
+        )
+
+        val actualPoppedItems = stackState.popItems(setOf("GROUP_1", "GROUP_3"))
+
+        Truth.assertThat(actualPoppedItems).containsExactly(
+            StackItem("TAG1", "GROUP_1"),
+            StackItem("TAG3", "GROUP_1"),
+            StackItem("TAG4", "GROUP_3"),
+        ).inOrder()
+        Truth.assertThat(stackState.fragmentTagStack[0]).containsExactly(
+            StackItem("ROOT"),
+            StackItem("TAG2", "GROUP_2"),
+        ).inOrder()
+    }
 }