RUM-18048: Fix Fabric text mapping in minified Android builds

Author: jonathanmos

packages/react-native-session-replay/android/src/main/kotlin/com/datadog/reactnative/sessionreplay/utils/text/FabricTextViewUtils.kt

@@ -1,17 +1,15 @@
 package com.datadog.reactnative.sessionreplay.utils.text
 
-import android.text.Spannable
 import android.text.style.ForegroundColorSpan
-import android.view.View
 import android.widget.TextView
-import com.datadog.android.api.InternalLogger
 import com.datadog.android.sessionreplay.model.MobileSegment
 import com.datadog.reactnative.sessionreplay.utils.DrawableUtils
 import com.datadog.reactnative.sessionreplay.utils.formatAsRgba
 import com.facebook.react.bridge.ReactContext
+import com.facebook.react.views.text.ReactTextView
 import java.util.Locale
 
-internal class FabricTextViewUtils(private val reactContext: ReactContext, private val logger: InternalLogger, drawableUtils: DrawableUtils): TextViewUtils(reactContext, drawableUtils) {
+internal class FabricTextViewUtils(reactContext: ReactContext, drawableUtils: DrawableUtils): TextViewUtils(reactContext, drawableUtils) {
 
     override fun resolveTextStyle(
         textWireframe: MobileSegment.Wireframe.TextWireframe,
@@ -31,7 +29,9 @@ internal class FabricTextViewUtils(private val reactContext: ReactContext, priva
     }
 
     private fun getTextColor(view: TextView, textWireframe: MobileSegment.Wireframe.TextWireframe): String {
-        val spanned = getFieldFromView(view, SPANNED_FIELD_NAME) as? Spannable
+        // Use the public accessor so R8 can rewrite the reference when it obfuscates ReactTextView.
+        // Looking up the private mSpanned field by name breaks in minified applications.
+        val spanned = (view as? ReactTextView)?.spanned
         val spans = spanned?.getSpans(0, spanned.length, ForegroundColorSpan::class.java)
         val fontColor = spans?.firstOrNull()?.foregroundColor?.let { formatAsRgba(it) } ?: textWireframe.textStyle.color
 
@@ -47,28 +47,4 @@ internal class FabricTextViewUtils(private val reactContext: ReactContext, priva
         val fontFamily = textWireframe.textStyle.family
         return resolveFontFamily(fontFamily.lowercase(Locale.US))
     }
-
-    internal fun getFieldFromView(view: View, value: String): Any? {
-        try {
-            val field = view.javaClass.getDeclaredField(value)
-            field.isAccessible = true
-            return field.get(view)
-        } catch (@Suppress("TooGenericExceptionCaught") e: Exception) {
-            when (e) {
-                is NoSuchFieldException -> handleError(e, RESOLVE_FABRICFIELD_ERROR)
-                is NullPointerException -> handleError(e, NULL_FABRICFIELD_ERROR)
-                else -> handleError(e, RESOLVE_FABRICFIELD_ERROR)
-            }
-            return null
-        }
-    }
-
-    private fun handleError(e: Exception, message: String) {
-        logger.log(
-            level = InternalLogger.Level.WARN,
-            targets = listOf(InternalLogger.Target.MAINTAINER, InternalLogger.Target.TELEMETRY),
-            messageBuilder = { message },
-            throwable = e
-        )
-    }
-}
+}

packages/react-native-session-replay/android/src/main/kotlin/com/datadog/reactnative/sessionreplay/utils/text/TextViewUtils.kt

@@ -141,23 +141,17 @@ internal abstract class TextViewUtils(private val reactContext: ReactContext, pr
 
     @VisibleForTesting
     companion object {
-        internal const val SPANNED_FIELD_NAME = "mSpanned"
-
         private const val ROBOTO_TYPEFACE_NAME = "roboto"
         private const val SERIF_FAMILY_NAME = "serif"
         private const val SANS_SERIF_FAMILY_NAME = "roboto, sans-serif"
         internal const val MONOSPACE_FAMILY_NAME = "monospace"
 
-        internal const val RESOLVE_FABRICFIELD_ERROR = "Unable to resolve field from fabric view"
-        internal const val NULL_FABRICFIELD_ERROR = "Null value found when trying to resolve field from fabric view"
-
-
         fun create(reactContext: ReactContext, logger: InternalLogger): TextViewUtils {
             return when (BuildConfig.IS_NEW_ARCHITECTURE_ENABLED) {
-                true -> FabricTextViewUtils(reactContext, logger, ReactViewBackgroundDrawableUtils())
+                true -> FabricTextViewUtils(reactContext, ReactViewBackgroundDrawableUtils())
                 false -> LegacyTextViewUtils(reactContext, logger, ReactViewBackgroundDrawableUtils())
             }
         }
     }
 
-}
+}

packages/react-native-session-replay/android/src/test/kotlin/com/datadog/reactnative/sessionreplay/utils/text/TextViewUtilsTest.kt

@@ -23,6 +23,7 @@ import com.datadog.reactnative.sessionreplay.utils.formatAsRgba
 import com.datadog.reactnative.sessionreplay.utils.text.TextViewUtils.Companion.MONOSPACE_FAMILY_NAME
 import com.datadog.reactnative.tools.unit.forge.ForgeConfigurator
 import com.facebook.react.bridge.ReactContext
+import com.facebook.react.views.text.ReactTextView
 import com.facebook.react.views.text.internal.span.CustomStyleSpan
 import com.facebook.react.views.view.ReactViewBackgroundDrawable
 import fr.xgouchet.elmyr.Forge
@@ -42,7 +43,6 @@ import org.mockito.Mockito.mock
 import org.mockito.Mockito.spy
 import org.mockito.junit.jupiter.MockitoExtension
 import org.mockito.junit.jupiter.MockitoSettings
-import org.mockito.kotlin.any
 import org.mockito.kotlin.eq
 import org.mockito.kotlin.whenever
 import org.mockito.quality.Strictness
@@ -60,6 +60,9 @@ internal class TextViewUtilsTest {
     @Mock
     lateinit var mockTextView: TextView
 
+    @Mock
+    lateinit var mockReactTextView: ReactTextView
+
     @Mock
     lateinit var mockReactViewBackgroundDrawable: ReactViewBackgroundDrawable
 
@@ -116,12 +119,11 @@ internal class TextViewUtilsTest {
         val realFabricUtils =
             FabricTextViewUtils(
                 mockReactContext,
-                mockLogger,
                 mockDrawableUtils
             )
 
         testedUtils = spy(realUtils)
-        fabricTestedUtils = spy(realFabricUtils)
+        fabricTestedUtils = realFabricUtils
     }
 
     @Test
@@ -455,14 +457,20 @@ internal class TextViewUtilsTest {
         whenever(mockForegroundColorSpan.foregroundColor).thenReturn(-1)
 
         val spannable = mock(Spannable::class.java)
-        doReturn(spannable).whenever(fabricTestedUtils).getFieldFromView(any(), any())
+        whenever(mockReactTextView.spanned).thenReturn(spannable)
+        whenever(mockReactTextView.background).thenReturn(null)
+        whenever(mockReactTextView.textSize).thenReturn(16f)
 
         whenever(spannable.getSpans(anyInt(), anyInt(), eq(ForegroundColorSpan::class.java)))
             .thenReturn(
                 arrayOf(mockForegroundColorSpan)
             )
 
-        val result = fabricTestedUtils.addReactNativeProperties(fakeWireframe, mockTextView, 0f)
+        val result = fabricTestedUtils.addReactNativeProperties(
+            fakeWireframe,
+            mockReactTextView,
+            0f
+        )
         assertThat(result.textStyle.color).isEqualTo("#ffffffff")
     }