[fenix] For https://github.com/mozilla-mobile/fenix/issues/22879: Filter default engines when sending telemetry.

Filter out custom engines that are not well known search domains.

app/metrics.yaml

@@ -1842,7 +1842,7 @@ search.default_engine:
       URL we use to build the search query for the search engine. For example:
       https://mysearchengine.com/?query=%s. If it's a custom search engine
       (defined: https://github.com/mozilla-mobile/fenix/issues/1607) the value
-      will be "custom"
+      will not be set.
     send_in_pings:
       - metrics
     bugs:

app/src/main/java/org/mozilla/fenix/FenixApplication.kt

@@ -80,6 +80,8 @@ import org.mozilla.fenix.components.Core
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.components.metrics.MozillaProductDetector
 import org.mozilla.fenix.components.toolbar.ToolbarPosition
+import org.mozilla.fenix.ext.isCustomEngine
+import org.mozilla.fenix.ext.isKnownSearchDomain
 import org.mozilla.fenix.perf.MarkersActivityLifecycleCallbacks
 import org.mozilla.fenix.utils.Settings
 
@@ -643,11 +645,20 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
         }
 
         browserStore.waitForSelectedOrDefaultSearchEngine { searchEngine ->
-            if (searchEngine != null) {
-                SearchDefaultEngine.apply {
-                    code.set(searchEngine.id)
-                    name.set(searchEngine.name)
-                    searchUrl.set(searchEngine.buildSearchUrl(""))
+            searchEngine?.let {
+                val sendSearchUrl =
+                    !searchEngine.isCustomEngine() || searchEngine.isKnownSearchDomain()
+                if (sendSearchUrl) {
+                    SearchDefaultEngine.apply {
+                        code.set(searchEngine.id)
+                        name.set(searchEngine.name)
+                        searchUrl.set(searchEngine.buildSearchUrl(""))
+                    }
+                } else {
+                    SearchDefaultEngine.apply {
+                        code.set(searchEngine.id)
+                        name.set("custom")
+                    }
                 }
             }
         }

app/src/main/java/org/mozilla/fenix/ext/SearchEngine.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.ext
+
+import mozilla.components.browser.state.search.SearchEngine
+
+// List of well known search domains, taken from
+// https://searchfox.org/mozilla-central/source/toolkit/components/search/SearchService.jsm#2405
+private val wellKnownSearchDomains = setOf(
+    "aol",
+    "ask",
+    "baidu",
+    "bing",
+    "duckduckgo",
+    "google",
+    "yahoo",
+    "yandex",
+    "startpage"
+)
+
+/**
+ * Whether or not the search engine is a custom engine added by the user.
+ */
+fun SearchEngine.isCustomEngine(): Boolean =
+    this.type == SearchEngine.Type.CUSTOM
+
+/**
+ * Whether or not the search engine is a known search domain.
+ */
+fun SearchEngine.isKnownSearchDomain(): Boolean =
+    this.resultUrls[0].findAnyOf(wellKnownSearchDomains, 0, true) != null

app/src/test/java/org/mozilla/fenix/ext/SearchEngineTest.kt

@@ -0,0 +1,67 @@
+/* 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.ext
+
+import mozilla.components.browser.state.search.SearchEngine
+import mozilla.components.support.test.mock
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import java.util.UUID
+
+class SearchEngineTest {
+
+    @Test
+    fun `custom search engines are identified correctly`() {
+        val searchEngine = SearchEngine(
+            id = UUID.randomUUID().toString(),
+            name = "Not custom",
+            icon = mock(),
+            type = SearchEngine.Type.BUNDLED,
+            resultUrls = listOf(
+                "https://www.startpage.com/sp/search?q={searchTerms}"
+            )
+        )
+
+        val customSearchEngine = SearchEngine(
+            id = UUID.randomUUID().toString(),
+            name = "Custom",
+            icon = mock(),
+            type = SearchEngine.Type.CUSTOM,
+            resultUrls = listOf(
+                "https://www.startpage.com/sp/search?q={searchTerms}"
+            )
+        )
+
+        assertFalse(searchEngine.isCustomEngine())
+        assertTrue(customSearchEngine.isCustomEngine())
+    }
+
+    @Test
+    fun `well known search engines are identified correctly`() {
+        val searchEngine = SearchEngine(
+            id = UUID.randomUUID().toString(),
+            name = "Not well known",
+            icon = mock(),
+            type = SearchEngine.Type.BUNDLED,
+            resultUrls = listOf(
+                "https://www.random.com/sp/search?q={searchTerms}"
+            )
+        )
+
+        val wellKnownSearchEngine = SearchEngine(
+            id = UUID.randomUUID().toString(),
+            name = "Well known",
+            icon = mock(),
+            type = SearchEngine.Type.CUSTOM,
+            resultUrls = listOf(
+                "https://www.startpage.com/sp/search?q={searchTerms}"
+            )
+        )
+
+        assertFalse(searchEngine.isKnownSearchDomain())
+        assertTrue(wellKnownSearchEngine.isKnownSearchDomain())
+    }
+}