Generate null MapTiler BuildConfig values when not provided

Remove the default values from the Gradle file, the public MapTiler defaults
are now only defined in MapTilerDefaults. buildConfigFieldStr now accepts a
null value.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

features/location/api/build.gradle.kts

@@ -26,7 +26,7 @@ android {
     defaultConfig {
         buildConfigFieldStr(
             name = "MAPTILER_BASE_URL",
-            value = BuildTimeConfig.SERVICES_MAPTILER_BASE_URL ?: "https://api.maptiler.com/maps"
+            value = BuildTimeConfig.SERVICES_MAPTILER_BASE_URL,
         )
         buildConfigFieldStr(
             name = "MAPTILER_API_KEY",
@@ -35,8 +35,7 @@ android {
             } else {
                 System.getenv("ELEMENT_ANDROID_MAPTILER_API_KEY")
                     ?: readLocalProperty("services.maptiler.apikey")
-            }
-                ?: ""
+            },
         )
         buildConfigFieldStr(
             name = "MAPTILER_LIGHT_MAP_ID",
@@ -45,9 +44,7 @@ android {
             } else {
                 System.getenv("ELEMENT_ANDROID_MAPTILER_LIGHT_MAP_ID")
                     ?: readLocalProperty("services.maptiler.lightMapId")
-            }
-            // fall back to maptiler's default light map.
-                ?: "basic-v2"
+            },
         )
         buildConfigFieldStr(
             name = "MAPTILER_DARK_MAP_ID",
@@ -56,9 +53,7 @@ android {
             } else {
                 System.getenv("ELEMENT_ANDROID_MAPTILER_DARK_MAP_ID")
                     ?: readLocalProperty("services.maptiler.darkMapId")
-            }
-            // fall back to maptiler's default dark map.
-                ?: "basic-v2-dark"
+            },
         )
     }
 }

features/location/api/src/main/kotlin/io/element/android/features/location/api/LocalMapTilerConfig.kt

@@ -19,14 +19,13 @@ val LocalMapTilerConfig = staticCompositionLocalOf { buildTimeMapTilerConfig() }
  * The [MapTilerConfig] defined at build time, or null if no MapTiler API key has been provided.
  */
 fun buildTimeMapTilerConfig(): MapTilerConfig? {
-    return BuildConfig.MAPTILER_API_KEY
-        .takeIf { it.isNotEmpty() }
-        ?.let { apiKey ->
-            MapTilerConfig(
-                apiKey = apiKey,
-                lightStyleId = BuildConfig.MAPTILER_LIGHT_MAP_ID,
-                darkStyleId = BuildConfig.MAPTILER_DARK_MAP_ID,
-                baseUrl = BuildConfig.MAPTILER_BASE_URL
-            )
-        }
+    // BuildConfig fields are null when not provided at build time.
+    val apiKey: String? = BuildConfig.MAPTILER_API_KEY
+    if (apiKey.isNullOrEmpty()) return null
+    return MapTilerConfig(
+        apiKey = apiKey,
+        lightStyleId = BuildConfig.MAPTILER_LIGHT_MAP_ID,
+        darkStyleId = BuildConfig.MAPTILER_DARK_MAP_ID,
+        baseUrl = BuildConfig.MAPTILER_BASE_URL,
+    )
 }

features/location/impl/src/test/kotlin/io/element/android/features/location/impl/DefaultLocationServiceTest.kt

@@ -11,7 +11,6 @@ package io.element.android.features.location.impl
 import com.google.common.truth.Truth.assertThat
 import io.element.android.features.enterprise.api.remoteconfig.CustomMapTilerConfigProvider
 import io.element.android.features.enterprise.test.remoteconfig.aMapTilerConfig
-import io.element.android.features.location.api.BuildConfig
 import io.element.android.features.location.api.buildTimeMapTilerConfig
 import io.element.android.libraries.matrix.test.AN_EXCEPTION
 import kotlinx.coroutines.CoroutineScope
@@ -30,7 +29,7 @@ class DefaultLocationServiceTest {
         )
         runCurrent()
         assertThat(locationService.mapTilerConfig.value).isEqualTo(buildTimeMapTilerConfig())
-        assertThat(locationService.isServiceAvailable().value).isEqualTo(BuildConfig.MAPTILER_API_KEY.isNotEmpty())
+        assertThat(locationService.isServiceAvailable().value).isEqualTo(buildTimeMapTilerConfig() != null)
     }
 
     @Test
@@ -40,7 +39,7 @@ class DefaultLocationServiceTest {
         )
         runCurrent()
         assertThat(locationService.mapTilerConfig.value).isEqualTo(buildTimeMapTilerConfig())
-        assertThat(locationService.isServiceAvailable().value).isEqualTo(BuildConfig.MAPTILER_API_KEY.isNotEmpty())
+        assertThat(locationService.isServiceAvailable().value).isEqualTo(buildTimeMapTilerConfig() != null)
     }
 
     @Test

plugins/src/main/kotlin/extension/VariantDimensionExtension.kt

@@ -10,14 +10,17 @@ package extension
 
 import com.android.build.api.dsl.VariantDimension
 
+/**
+ * Adds a String field to the generated BuildConfig class. If [value] is null, the field will be null.
+ */
 fun VariantDimension.buildConfigFieldStr(
     name: String,
-    value: String,
+    value: String?,
 ) {
     buildConfigField(
         type = "String",
         name = name,
-        value = "\"$value\""
+        value = value?.let { "\"$it\"" } ?: "null"
     )
 }