Fixes #3906: Incorrect output for rich text in hints and solution

app/src/main/java/org/oppia/android/app/hintsandsolution/HintsViewModel.kt

@@ -12,6 +12,7 @@ import org.oppia.android.app.translation.AppLanguageResourceHandler
 import org.oppia.android.domain.hintsandsolution.isHintRevealed
 import org.oppia.android.domain.hintsandsolution.isSolutionRevealed
 import org.oppia.android.domain.translation.TranslationController
+import org.oppia.android.util.parser.html.CustomHtmlContentHandler
 import javax.inject.Inject
 
 private const val DEFAULT_HINT_AND_SOLUTION_SUMMARY = ""
@@ -82,7 +83,13 @@ class HintsViewModel @Inject constructor(
   fun computeHintListDropDownIconContentDescription(): String {
     return resourceHandler.getStringInLocaleWithWrapping(
       R.string.show_hide_hint_list,
-      hintsAndSolutionSummary.get() ?: DEFAULT_HINT_AND_SOLUTION_SUMMARY
+      hintsAndSolutionSummary.get()?.let {
+        CustomHtmlContentHandler.fromHtml(
+          it,
+          imageRetriever = null,
+          customTagHandlers = mapOf()
+        )
+      } ?: DEFAULT_HINT_AND_SOLUTION_SUMMARY
     )
   }
 

app/src/main/res/layout/hints_summary.xml

@@ -124,6 +124,7 @@
           android:layout_height="wrap_content"
           android:background="@color/component_color_hints_and_solution_summary_bottom_background_color"
           android:fontFamily="sans-serif"
+          android:importantForAccessibility="no"
           android:paddingStart="12dp"
           android:paddingTop="16dp"
           android:paddingEnd="12dp"

app/src/sharedTest/java/org/oppia/android/app/player/exploration/ExplorationActivityTest.kt

@@ -1617,6 +1617,48 @@ class ExplorationActivityTest {
     explorationDataController.stopPlayingExploration(isCompletion = false)
   }
 
+  @Test
+  @RunOn(TestPlatform.ROBOLECTRIC) // TODO(#3858): Enable for Espresso.
+  fun testExpActivity_showHintAndSolution_hasCorrectContentDescription() {
+    launch<ExplorationActivity>(
+      createExplorationActivityIntent(
+        internalProfileId,
+        TEST_TOPIC_ID_0,
+        TEST_STORY_ID_0,
+        TEST_EXPLORATION_ID_2,
+        shouldSavePartialProgress = false
+      )
+    ).use {
+      explorationDataController.startPlayingNewExploration(
+        internalProfileId,
+        TEST_TOPIC_ID_0,
+        TEST_STORY_ID_0,
+        TEST_EXPLORATION_ID_2
+      )
+      testCoroutineDispatchers.runCurrent()
+      clickContinueButton()
+      // Submit two incorrect answers.
+      submitFractionAnswer(answerText = "1/3")
+      submitFractionAnswer(answerText = "1/4")
+
+      // Reveal the hint.
+      openHintsAndSolutionsDialog()
+      pressRevealHintButton(hintPosition = 0)
+
+      // Ensure the hint description is correct and doesn't contain any HTML.
+      onView(withId(R.id.expand_list_icon))
+        .check(
+          matches(
+            withContentDescription(
+              "Show/Hide hint list of Remember that two halves, when added together," +
+                " make one whole.\n\n"
+            )
+          )
+        )
+    }
+    explorationDataController.stopPlayingExploration(isCompletion = false)
+  }
+
   // TODO(#3858): Enable for Espresso.
   @Test
   @RunOn(TestPlatform.ROBOLECTRIC, buildEnvironments = [BuildEnvironment.BAZEL])

app/src/sharedTest/java/org/oppia/android/app/topic/questionplayer/QuestionPlayerActivityTest.kt

@@ -23,6 +23,7 @@ import androidx.test.espresso.matcher.RootMatchers.isDialog
 import androidx.test.espresso.matcher.ViewMatchers.isCompletelyDisplayed
 import androidx.test.espresso.matcher.ViewMatchers.isDisplayed
 import androidx.test.espresso.matcher.ViewMatchers.isRoot
+import androidx.test.espresso.matcher.ViewMatchers.withContentDescription
 import androidx.test.espresso.matcher.ViewMatchers.withId
 import androidx.test.espresso.matcher.ViewMatchers.withText
 import androidx.test.ext.junit.runners.AndroidJUnit4
@@ -429,6 +430,33 @@ class QuestionPlayerActivityTest {
     }
   }
 
+  @Test
+  @RunOn(TestPlatform.ROBOLECTRIC) // TODO(#3858): Enable for Espresso.
+  fun testQuestionPlayer_showHintsAndSolution_hasCorrectContentDescription() {
+    updateContentLanguage(profileId, OppiaLanguage.ENGLISH)
+    launchForSkillList(SKILL_ID_LIST).use {
+      // Submit two incorrect answers.
+      selectMultipleChoiceOption(optionPosition = 3)
+      selectMultipleChoiceOption(optionPosition = 3)
+
+      // Reveal the hint.
+      openHintsAndSolutionsDialog()
+      pressRevealHintButton(hintPosition = 0)
+
+      // Ensure the hint description is correct and doesn't contain any HTML.
+      onView(withId(R.id.expand_list_icon))
+        .check(
+          matches(
+            withContentDescription(
+              "Show/Hide hint list of To write a fraction, you need to know " +
+                "its denominator, which is the total number of pieces in the whole. " +
+                "All of these pieces should be the same size.\n\n"
+            )
+          )
+        )
+    }
+  }
+
   // TODO(#3858): Enable for Espresso.
   @Test
   @RunOn(TestPlatform.ROBOLECTRIC, buildEnvironments = [BuildEnvironment.BAZEL])