Merge styles with Choice custom styles (#362)

---------

Co-authored-by: Kian Cross <kian@kiancross.co.uk>

Author: ahnucl

questionary/prompts/common.py

@@ -472,7 +472,16 @@ def append(index: int, choice: Choice):
                     tokens.append(("class:text", "{}".format(indicator)))
 
                 if isinstance(choice.title, list):
-                    tokens.extend(choice.title)
+                    if selected:
+                        extra_style = " class:selected"
+                    elif index == self.pointed_at:
+                        extra_style = " class:highlighted"
+                    else:
+                        extra_style = ""
+                    tokens.extend(
+                        (fragment[0] + extra_style, fragment[1])
+                        for fragment in choice.title
+                    )
                 elif selected:
                     tokens.append(
                         ("class:selected", "{}{}".format(shortcut, choice.title))

tests/prompts/test_common.py

@@ -137,6 +137,44 @@ def test_prompt_highlight_coexist():
     assert ic._get_choice_tokens() == expected_tokens
 
 
+def test_prompt_highlight_selected_with_custom_styles():
+    # formatted-text (list) titles should keep their custom style and also
+    # pick up the highlighted/selected style (see #151)
+    ic = InquirerControl(
+        [
+            Choice(title=[("fg:red", "a")]),
+            Choice(title=[("fg:blue", "b")], checked=True),
+        ]
+    )
+
+    expected_tokens = [
+        ("class:pointer", " » "),
+        ("[SetCursorPosition]", ""),
+        ("class:text", "○ "),
+        ("fg:red class:highlighted", "a"),
+        ("", "\n"),
+        ("class:text", "   "),
+        ("class:selected", "● "),
+        ("fg:blue class:selected", "b"),
+    ]
+    assert ic.pointed_at == 0
+    assert ic._get_choice_tokens() == expected_tokens
+
+    ic.select_next()
+    expected_tokens = [
+        ("class:text", "   "),
+        ("class:text", "○ "),
+        ("fg:red", "a"),
+        ("", "\n"),
+        ("class:pointer", " » "),
+        ("[SetCursorPosition]", ""),
+        ("class:selected", "● "),
+        ("fg:blue class:selected", "b"),
+    ]
+    assert ic.pointed_at == 1
+    assert ic._get_choice_tokens() == expected_tokens
+
+
 def test_prompt_show_answer_with_shortcuts():
     ic = InquirerControl(
         ["a", Choice("b", shortcut_key=False), "c"],