[fenix] For https://github.com/mozilla-mobile/fenix/issues/28273 - Configure search with the selected search engine before user searching

app/src/main/java/org/mozilla/fenix/search/SearchDialogFragment.kt

@@ -105,7 +105,7 @@ class SearchDialogFragment : AppCompatDialogFragment(), UserInteractionHandler {
     private var _binding: FragmentSearchDialogBinding? = null
     private val binding get() = _binding!!
 
-    private lateinit var interactor: SearchDialogInteractor
+    @VisibleForTesting internal lateinit var interactor: SearchDialogInteractor
     private lateinit var store: SearchDialogFragmentStore
     private lateinit var toolbarView: ToolbarView
     private lateinit var inlineAutocompleteEditText: InlineAutocompleteEditText
@@ -266,6 +266,9 @@ class SearchDialogFragment : AppCompatDialogFragment(), UserInteractionHandler {
 
         requireComponents.core.engine.speculativeCreateSession(isPrivate)
 
+        // Handle the scenario in which the user selects another search engine before starting a search.
+        maybeSelectShortcutEngine(args.searchEngine)
+
         when (getPreviousDestination()?.destination?.id) {
             R.id.homeFragment -> {
                 // When displayed above home, dispatches the touch events to scrim area to the HomeFragment
@@ -477,6 +480,26 @@ class SearchDialogFragment : AppCompatDialogFragment(), UserInteractionHandler {
         }
     }
 
+    /**
+     * Check whether the search engine identified by [selectedSearchEngineId] is the default search engine
+     * and if not update the search state to reflect that a different search engine is currently selected.
+     *
+     * @param selectedSearchEngineId Id of the search engine currently selected for next searches.
+     */
+    @VisibleForTesting
+    internal fun maybeSelectShortcutEngine(selectedSearchEngineId: String?) {
+        if (selectedSearchEngineId == null) return
+
+        val searchState = requireComponents.core.store.state.search
+        searchState.searchEngines.firstOrNull {
+            it.id == selectedSearchEngineId
+        }?.let { selectedSearchEngine ->
+            if (selectedSearchEngine != searchState.selectedOrDefaultSearchEngine) {
+                interactor.onSearchShortcutEngineSelected(selectedSearchEngine)
+            }
+        }
+    }
+
     private fun isTouchingPrivateButton(x: Float, y: Float): Boolean {
         val view = parentFragmentManager.primaryNavigationFragment?.view?.findViewInHierarchy {
             it.id == R.id.privateBrowsingButton

app/src/test/java/org/mozilla/fenix/search/SearchDialogFragmentTest.kt

@@ -8,15 +8,25 @@ import androidx.fragment.app.Fragment
 import androidx.navigation.NavBackStackEntry
 import androidx.navigation.NavController
 import androidx.navigation.fragment.findNavController
+import io.mockk.Called
+import io.mockk.Runs
 import io.mockk.every
+import io.mockk.just
 import io.mockk.mockk
 import io.mockk.mockkStatic
 import io.mockk.unmockkStatic
+import io.mockk.verify
+import mozilla.components.browser.state.search.SearchEngine
+import mozilla.components.browser.state.state.SearchState
+import mozilla.components.browser.state.state.searchEngines
+import mozilla.components.browser.state.state.selectedOrDefaultSearchEngine
 import org.junit.After
 import org.junit.Assert.assertNull
 import org.junit.Assert.assertSame
 import org.junit.Before
 import org.junit.Test
+import org.mozilla.fenix.components.Components
+import org.mozilla.fenix.ext.requireComponents
 
 internal class SearchDialogFragmentTest {
     private val navController: NavController = mockk()
@@ -78,6 +88,71 @@ internal class SearchDialogFragmentTest {
 
         assertSame(fragmentADestination, fragment.getPreviousDestination())
     }
+
+    @Test
+    fun `GIVEN the default search engine is currently selected WHEN checking the need to update the current search engine THEN don't to anything`() {
+        fragment.interactor = mockk()
+        val defaultSearchEngine: SearchEngine = mockk {
+            every { id } returns "default"
+        }
+        val otherSearchEngine: SearchEngine = mockk {
+            every { id } returns "other"
+        }
+        val components: Components = mockk {
+            every { core.store.state.search } returns mockk(relaxed = true) {
+                every { searchEngines } returns listOf(otherSearchEngine, defaultSearchEngine)
+            }
+        }
+        mockkStatic(
+            "org.mozilla.fenix.ext.FragmentKt",
+            "mozilla.components.browser.state.state.SearchStateKt",
+        ) {
+            every { any<Fragment>().requireComponents } returns components
+            every { any<SearchState>().selectedOrDefaultSearchEngine } returns defaultSearchEngine
+
+            fragment.maybeSelectShortcutEngine(defaultSearchEngine.id)
+
+            verify { fragment.interactor wasNot Called }
+        }
+    }
+
+    @Test
+    fun `GIVEN the default search engine is not currently selected WHEN checking the need to update the current search engine THEN update it to the current engine`() {
+        fragment.interactor = mockk {
+            every { onSearchShortcutEngineSelected(any()) } just Runs
+        }
+        val defaultSearchEngine: SearchEngine = mockk {
+            every { id } returns "default"
+        }
+        val otherSearchEngine: SearchEngine = mockk {
+            every { id } returns "other"
+        }
+        val components: Components = mockk {
+            every { core.store.state.search } returns mockk(relaxed = true) {
+                every { searchEngines } returns listOf(otherSearchEngine, defaultSearchEngine)
+            }
+        }
+        mockkStatic(
+            "org.mozilla.fenix.ext.FragmentKt",
+            "mozilla.components.browser.state.state.SearchStateKt",
+        ) {
+            every { any<Fragment>().requireComponents } returns components
+            every { any<SearchState>().selectedOrDefaultSearchEngine } returns defaultSearchEngine
+
+            fragment.maybeSelectShortcutEngine(otherSearchEngine.id)
+
+            verify { fragment.interactor.onSearchShortcutEngineSelected(otherSearchEngine) }
+        }
+    }
+
+    @Test
+    fun `GIVEN the currently selected search engine is unknown WHEN checking the need to update the current search engine THEN don't do anything`() {
+        fragment.interactor = mockk()
+
+        fragment.maybeSelectShortcutEngine(null)
+
+        verify { fragment.interactor wasNot Called }
+    }
 }
 
 private val fragmentName = SearchDialogFragment::class.java.canonicalName?.substringAfterLast('.')!!