fix: include answer_text of self_check questions in the quiz payload

controllers/api/json.go

@@ -62,15 +62,18 @@ type quizJSON struct {
 }
 
 // questionJSON is a question as the player sees it before answering: no
-// is_correct, explanation or answer_text.
+// is_correct or explanation, and no answer_text except for self_check
+// flashcards, which have no solution to hide.
 type questionJSON struct {
-	ID        uint         `json:"id"`
-	Text      string       `json:"text"`
-	Type      string       `json:"type"`
-	Category  *string      `json:"category"`
-	Points    int          `json:"points"`
-	SortOrder int          `json:"sort_order"`
-	Answers   []answerJSON `json:"answers"`
+	ID        uint    `json:"id"`
+	Text      string  `json:"text"`
+	Type      string  `json:"type"`
+	Category  *string `json:"category"`
+	Points    int     `json:"points"`
+	SortOrder int     `json:"sort_order"`
+	// AnswerText is the model answer of a self_check question only.
+	AnswerText *string      `json:"answer_text,omitempty"`
+	Answers    []answerJSON `json:"answers"`
 }
 
 type answerJSON struct {
@@ -110,6 +113,9 @@ func question(q models.Question) questionJSON {
 		SortOrder: q.SortOrder,
 		Answers:   make([]answerJSON, 0, len(q.Answers)),
 	}
+	if q.Type == models.TypeSelfCheck {
+		out.AnswerText = q.AnswerText
+	}
 	for _, a := range q.Answers {
 		out.Answers = append(out.Answers, answerJSON{ID: a.ID, Text: a.Text})
 	}