requirements: Unpin pygments from ~=2.15.1 to >=2.14.0.

Pygments 2.16.0 introduced a style to support a combination of bold and
italic styling in pygments/pygments#2444. Both of our gruvbox themes and
the light native theme gain a 'bold strong' style via pygments as a
result, which urwid fails to parse and blocks the application from
loading.

This was temporarily fixed by pinning pygments at ~=2.15.1 in zulip#1433.

Method `translate_styles` manually converts the pygments `bold italic`
style into the urwid-compatible `bold, italics` is there.

Unpin Pygments from ~=2.15.1 to >=2.14.0.

Fixes part of zulip#1434.

setup.py

@@ -100,7 +100,7 @@ def long_description():
         "urwid_readline>=0.13",
         "beautifulsoup4>=4.11.1",
         "lxml>=4.9.2",
-        "pygments~=2.15.1",
+        "pygments>=2.14.0",
         "typing_extensions~=4.5.0",
         "python-dateutil>=2.8.2",
         "pytz>=2022.7.1",

tests/config/test_themes.py

@@ -22,7 +22,7 @@
     generate_pygments_styles,
     generate_theme,
     parse_themefile,
-    translate_pygments_styles_to_urwid_styles,
+    generate_urwid_compatible_pygments_styles,
     valid_16_color_codes,
     validate_colors,
 )
@@ -407,7 +407,7 @@ class Color3(Enum):
 
 
 @pytest.mark.parametrize(
-    "pygments_styles, urwid_styles, style_translations",
+    "pygments_styles, expected_styles, style_translations",
     [
         case(
             {},
@@ -444,23 +444,23 @@ class Color3(Enum):
         case(
             {
                 "token1": "style italic",
-                "token3": "#abc",
+                "token2": "#abc",
             },
             {
                 "token1": "newstyle italic",
-                "token3": "#abc",
+                "token2": "#abc",
             },
             {"style": "newstyle"},
             id="custom_translations",
         ),
     ],
 )
-def test_translate_pygments_styles_to_urwid_styles(
+def test_generate_urwid_compatible_pygments_styles(
     pygments_styles: Dict[_TokenType, str],
-    urwid_styles: Dict[_TokenType, str],
+    expected_styles: Dict[_TokenType, str],
     style_translations: Dict[str, str],
 ) -> None:
-    translated_styles = translate_pygments_styles_to_urwid_styles(
+    generated_styles = generate_urwid_compatible_pygments_styles(
         pygments_styles, style_translations
     )
-    assert sorted(urwid_styles) == sorted(translated_styles)
+    assert sorted(expected_styles.items()) == sorted(generated_styles.items())

zulipterminal/config/themes.py

@@ -262,20 +262,17 @@ def parse_themefile(
     return urwid_theme
 
 
-def translate_pygments_styles_to_urwid_styles(
+def generate_urwid_compatible_pygments_styles(
     pygments_styles: Dict[_TokenType, str],
     style_translations: Dict[str, str] = STYLE_TRANSLATIONS,
 ) -> Dict[_TokenType, str]:
-    """
-    This function translates pygments styles into urwid compatible styles.
-    """
-    urwid_styles = {}
+    urwid_compatible_styles = {}
     for token, style in pygments_styles.items():
         updated_style = style
         for old_value, new_value in style_translations.items():
             updated_style = updated_style.replace(old_value, new_value)
-        urwid_styles[token] = updated_style
-    return urwid_styles
+        urwid_compatible_styles[token] = updated_style
+    return urwid_compatible_styles
 
 
 def generate_pygments_styles(pygments: Dict[str, Any]) -> ThemeSpec:
@@ -301,8 +298,7 @@ def generate_pygments_styles(pygments: Dict[str, Any]) -> ThemeSpec:
     term16_bg = term16.background_color
 
     theme_styles_from_pygments: ThemeSpec = []
-
-    pygments_styles = translate_pygments_styles_to_urwid_styles(pygments_styles)
+    pygments_styles = generate_urwid_compatible_pygments_styles(pygments_styles)
 
     for token, css_class in STANDARD_TYPES.items():
         if css_class in pygments_overrides: