fix(editor): align Python identifier colors and unused-parameter styling (#1572)

Python defaults diverged in several places: built-ins used the predefined magenta, __init__/__doc__ used function/self colours, instance fields the property colour, f-strings and byte strings the generic string colour, and the PEP 695 type keyword was uncoloured. Python now has its own tokens for built-ins, predefined definitions/usages, f-strings and byte strings; instance fields follow identifiers; type is a keyword. Unused parameters (not reported by Pyrefly) are greyed by a scope-aware local check that skips self/cls/_ names and signatures dictated elsewhere: stubs, @abstractmethod/@overload/@override, dunder methods and methods of classes with bases.

Co-authored-by: muutot <[email protected]>
Co-Authored-By: Claude Opus 5.5 <[email protected]>

e2e/pythonHighlight.fixture.ts

@@ -26,6 +26,9 @@ const attributes = {
   "PY.SELF_PARAMETER": { FOREGROUND: "aa7788" },
   "PY.BUILTIN_NAME": { FOREGROUND: "bb8899" },
   "PY.KEYWORD_ARGUMENT": { FOREGROUND: "cc99aa" },
+  "PY.STRING.F": { FOREGROUND: "aa8811" },
+  "PY.PREDEFINED_DEFINITION": { FOREGROUND: "bb9922" },
+  "PY.PREDEFINED_USAGE": { FOREGROUND: "ccaa33" },
   OPENIDEA_pyLocalVariable: { FOREGROUND: "aa1101" },
   OPENIDEA_pyGlobalVariable: { FOREGROUND: "aa2202" },
   OPENIDEA_pyInstanceAttribute: { FOREGROUND: "aa3303" },
@@ -52,6 +55,8 @@ new EditorView({
   parent: document.body,
   state: EditorState.create({
     doc: `MAX_SIZE: Final = 10
+type Alias = list[int]
+fstr = f"value={1}"
 name = "global"
 T = TypeVar("T")
 
@@ -69,9 +74,13 @@ class Foo[T]:
         self.instance_attr = value
         print(local, MAX_SIZE, name, T)
         self.run(whatever=1) # Comment
+        print(self.__doc__)
     @property
     def size(self) -> int:
         return self.instance_attr
+
+def unused(param):
+    return 1
 `,
     extensions: [
       support!,

e2e/pythonHighlight.spec.ts

@@ -7,8 +7,11 @@ test("Python syntax supplements retain PyCharm colours without a language server
   await expect(page.locator(".cm-content")).toBeVisible();
   await page.screenshot({ path: info.outputPath("before.png") });
   await page.goto("/e2e/pythonHighlight.html");
-  await expect(page.locator(".cm-sem-python-definition")).toHaveText("outer");
-  await expect(page.locator(".cm-sem-python-definition")).toHaveCSS("color", "rgb(34, 68, 102)");
+  await expect(page.locator(".cm-sem-python-definition").filter({ hasText: /^outer$/ })).toHaveText("outer");
+  await expect(page.locator(".cm-sem-python-definition").filter({ hasText: /^outer$/ })).toHaveCSS(
+    "color",
+    "rgb(34, 68, 102)",
+  );
   await expect(page.locator(".cm-sem-python-nested")).toHaveCSS("color", "rgb(51, 85, 119)");
   await expect(page.locator(".cm-sem-python-docstring")).toHaveCSS("color", "rgb(102, 136, 170)");
   await expect(page.locator(".cm-sem-python-docstring")).toHaveCSS("text-decoration-line", "none");
@@ -46,6 +49,11 @@ test("Python syntax supplements retain PyCharm colours without a language server
   await expect(page.locator(".cm-sem-python-constant").first()).toHaveCSS("color", "rgb(170, 85, 5)");
   await expect(page.locator(".cm-sem-python-property").first()).toHaveCSS("color", "rgb(170, 102, 6)");
   await expect(page.locator(".cm-sem-python-type-parameter").first()).toHaveCSS("color", "rgb(170, 119, 7)");
+  await expect(page.locator(".cm-sem-python-fstring").first()).toHaveCSS("color", "rgb(170, 136, 17)");
+  await expect(page.locator(".cm-sem-python-predefined-definition")).toHaveCSS("color", "rgb(187, 153, 34)");
+  await expect(page.locator(".cm-sem-python-predefined-usage")).toHaveCSS("color", "rgb(204, 170, 51)");
+  await expect(page.locator(".cm-sem-keyword").filter({ hasText: /^type$/ })).toHaveCSS("color", "rgb(17, 34, 51)");
+  await expect(page.locator(".cm-sem-unused")).toHaveCSS("color", "rgb(111, 115, 122)");
   expect(errors).toEqual([]);
   await page.screenshot({ path: info.outputPath("python-highlighting.png") });
 });