Fix #3946: Fix solution automatically revealing after first hint reveal

app/src/sharedTest/java/org/oppia/android/app/player/state/StateFragmentTest.kt

@@ -2603,6 +2603,7 @@ class StateFragmentTest {
     targetTextViewId: Int
   ) {
     scrollToViewType(SELECTION_INTERACTION)
+    // First, check that the option matches what's expected by the test.
     onView(
       atPositionOnView(
         recyclerViewId = R.id.selection_interaction_recyclerview,

domain/BUILD.bazel

@@ -50,6 +50,7 @@ DOMAIN_ASSETS = generate_assets_list_from_text_protos(
         "test_single_interactive_state_exp_with_one_hint_and_solution",
         "test_single_interactive_state_exp_with_one_hint_and_no_solution",
         "test_single_interactive_state_exp_with_only_solution",
+        "test_single_interactive_state_exp_with_solution_missing_answer",
     ],
     skills_file_names = [
         "skills",

domain/src/main/assets/test_exp_id_2.json

@@ -692,8 +692,20 @@
             "refresher_exploration_id": "",
             "missing_prerequisite_skill_id": ""
           },
-          "hints": [],
-          "solution": null
+          "hints": [{
+            "hint_content": {
+              "content_id": "hint_1",
+              "html": "<p>11 * 11 can be rephrased as 11 * 10, then add 11 at the end.</p>"
+            }
+          }],
+          "solution": {
+            "answer_is_exclusive": false,
+            "correct_answer": "",
+            "explanation": {
+              "content_id": "solution",
+              "html": "<p>11 times 11 is 121.</p>"
+            }
+          }
         },
         "classifier_model_id": "",
         "recorded_voiceovers": {
@@ -702,11 +714,37 @@
             "feedback_3": {},
             "feedback_1": {},
             "content": {},
-            "default_outcome": {}
+            "default_outcome": {},
+            "hint_1": {},
+            "solution": {}
           }
         },
         "written_translations": {
           "translations_mapping": {
+            "hint_1": {
+              "pt": {
+                "data_format": "html",
+                "translation": {"translation" : "<p> 11 * 11 pode ser reformulado como 11 * 10 e, em seguida, adicione 11 no final. </p>"},
+                "needs_update": false
+              },
+              "ar": {
+                "data_format": "html",
+                "translation": {"translation" : "يمكن إعادة صياغة <p> 11 * 11 على أنها 11 * 10، ثم أضف 11 في النهاية. </p>"},
+                "needs_update": false
+              }
+            },
+            "solution": {
+              "pt": {
+                "data_format": "html",
+                "translation": {"translation" : "<p> 11 vezes 11 é 121. </p>"},
+                "needs_update": false
+              },
+              "ar": {
+                "data_format": "html",
+                "translation": {"translation" : "<p> 11 مرات 11 هو 121. </p>"},
+                "needs_update": false
+              }
+            },
             "feedback_2": {
               "pt": {
                 "data_format": "html",

domain/src/main/assets/test_exp_id_2.textproto

@@ -825,10 +825,54 @@ states {
       value {
       }
     }
+    recorded_voiceovers {
+      key: "hint_1"
+      value {
+      }
+    }
+    recorded_voiceovers {
+      key: "solution"
+      value {
+      }
+    }
     content {
       html: "<p>What is 11 times 11?</p>"
       content_id: "content"
     }
+    written_translations {
+      key: "hint_1"
+      value {
+        translation_mapping {
+          key: "pt"
+          value {
+            html: "<p> 11 * 11 pode ser reformulado como 11 * 10 e, em seguida, adicione 11 no final. </p>"
+          }
+        }
+        translation_mapping {
+          key: "ar"
+          value {
+            html: "\331\212\331\205\331\203\331\206 \330\245\330\271\330\247\330\257\330\251 \330\265\331\212\330\247\330\272\330\251 <p> 11 * 11 \330\271\331\204\331\211 \330\243\331\206\331\207\330\247 11 * 10\330\214 \330\253\331\205 \330\243\330\266\331\201 11 \331\201\331\212 \330\247\331\204\331\206\331\207\330\247\331\212\330\251. </p>"
+          }
+        }
+      }
+    }
+    written_translations {
+      key: "solution"
+      value {
+        translation_mapping {
+          key: "pt"
+          value {
+            html: "<p> 11 vezes 11 \303\251 121. </p>"
+          }
+        }
+        translation_mapping {
+          key: "ar"
+          value {
+            html: "<p> 11 \331\205\330\261\330\247\330\252 11 \331\207\331\210 121. </p>"
+          }
+        }
+      }
+    }
     written_translations {
       key: "feedback_2"
       value {
@@ -970,6 +1014,19 @@ states {
           rule_type: "IsGreaterThan"
         }
       }
+      solution {
+        interaction_id: "NumericInput"
+        explanation {
+          html: "<p>11 times 11 is 121.</p>"
+          content_id: "solution"
+        }
+      }
+      hint {
+        hint_content {
+          html: "<p>11 * 11 can be rephrased as 11 * 10, then add 11 at the end.</p>"
+          content_id: "hint_1"
+        }
+      }
       default_outcome {
         dest_state_name: "NumberInput"
         feedback {

domain/src/main/assets/test_single_interactive_state_exp_with_solution_missing_answer.json

@@ -0,0 +1,112 @@
+{
+  "exploration_id": "test_single_interactive_state_exp_with_solution_missing_answer",
+  "version": 1,
+  "exploration": {
+    "init_state_name": "Text",
+    "states": {
+      "Text": {
+        "content": {
+          "content_id": "content",
+          "html": "<p>In which language does Oppia mean 'to learn'?</p>"
+        },
+        "interaction": {
+          "id": "TextInput",
+          "customization_args": {
+            "rows": {
+              "value": 1.0
+            },
+            "placeholder": {
+              "value": {
+                "content_id": "ca_placeholder_0",
+                "unicode_str": "Enter a language"
+              }
+            }
+          },
+          "answer_groups": [{
+            "rule_specs": [{
+              "rule_type": "Equals",
+              "inputs": {
+                "x": {
+                  "contentId": "<unknown>",
+                  "normalizedStrSet": ["finnish"]
+                }
+              }
+            }],
+            "outcome": {
+              "dest": "End",
+              "feedback": {
+                "content_id": "feedback_1",
+                "html": "<p>Correct!</p>"
+              },
+              "labelled_as_correct": false
+            }
+          }],
+          "default_outcome": {
+            "dest": "Text",
+            "feedback": {
+              "content_id": "default_outcome",
+              "html": "<p>Not quite. Try again (or maybe use a search engine).</p>"
+            },
+            "labelled_as_correct": false
+          },
+          "hints": [],
+          "solution": {
+            "answer_is_exclusive": false,
+            "explanation": {
+              "content_id": "solution",
+              "html": "<p>'Oppia' is translated from Finnish.</p>"
+            }
+          }
+        },
+        "recorded_voiceovers": {
+          "voiceovers_mapping": {
+            "feedback_1": {},
+            "content": {},
+            "default_outcome": {},
+            "solution": {}
+          }
+        },
+        "written_translations": {
+          "translations_mapping": {
+            "feedback_1": {},
+            "content": {},
+            "default_outcome": {},
+            "solution": {}
+          }
+        }
+      },
+      "End": {
+        "content": {
+          "content_id": "content",
+          "html": "Congratulations, you have finished!"
+        },
+        "param_changes": [],
+        "interaction": {
+          "id": "EndExploration",
+          "customization_args": {
+            "recommendedExplorationIds": {
+              "value": []
+            }
+          },
+          "answer_groups": [],
+          "default_outcome": null,
+          "hints": [],
+          "solution": null
+        },
+        "recorded_voiceovers": {
+          "voiceovers_mapping": {
+            "content": {}
+          }
+        },
+        "written_translations": {
+          "translations_mapping": {
+            "content": {}
+          }
+        }
+      }
+    },
+    "objective": "Test exploration.",
+    "language_code": "en",
+    "title": "Prototype exploration with only one solution and no hints"
+  }
+}