fix(tests): read static sources as UTF-8 in the static assertion tests (#6850)

On native Windows the default text encoding is the ANSI code page
(cp1252 on en/pt systems), so the module-level read_text() calls in
eight static tests fail at collection with UnicodeDecodeError on bytes
0x81/0x90 that appear in static/js/chat.js, chatRenderer.js, app.js,
index.html and src/visual_report.py. Pass encoding="utf-8" like the
other 700+ tests in the suite already do.

Found by running the suite natively on Windows 11 (Python 3.11).

Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
Co-authored-by: Alexandre Teixeira <general@alexandreteixeira.dev>

tests/test_agent_render_ownership.py

@@ -10,7 +10,7 @@ import unittest
 
 
 path = Path(__file__).resolve().parents[1] / "routes/chat_routes.py"
-tree = ast.parse(path.read_text())
+tree = ast.parse(path.read_text(encoding="utf-8"))
 node = next(n for n in tree.body if isinstance(n, ast.ClassDef) and n.name == "_AgentRenderState")
 namespace = {}
 exec(compile(ast.Module(body=[node], type_ignores=[]), str(path), "exec"), namespace)

tests/test_background_chat_completion_ui_static.py

@@ -3,8 +3,8 @@ from tests.helpers.stylesheets import app_css
 
 
 ROOT = Path(__file__).resolve().parents[1]
-CHAT = (ROOT / "static/js/chat.js").read_text()
-SESSIONS = (ROOT / "static/js/sessions.js").read_text()
+CHAT = (ROOT / "static/js/chat.js").read_text(encoding="utf-8")
+SESSIONS = (ROOT / "static/js/sessions.js").read_text(encoding="utf-8")
 CSS = app_css()
 
 

tests/test_chat_ttft_timer_static.py

@@ -2,8 +2,8 @@ from pathlib import Path
 
 
 ROOT = Path(__file__).resolve().parents[1]
-CHAT = (ROOT / "static/js/chat.js").read_text()
-RENDERER = (ROOT / "static/js/chatRenderer.js").read_text()
+CHAT = (ROOT / "static/js/chat.js").read_text(encoding="utf-8")
+RENDERER = (ROOT / "static/js/chatRenderer.js").read_text(encoding="utf-8")
 
 
 def test_processing_indicator_shows_live_ttft_timer():

tests/test_interrupted_resume_label_static.py

@@ -4,11 +4,11 @@ from tests.helpers.stylesheets import app_css
 
 
 ROOT = Path(__file__).resolve().parents[1]
-CHAT = (ROOT / "static/js/chat.js").read_text()
-RENDERER = (ROOT / "static/js/chatRenderer.js").read_text()
+CHAT = (ROOT / "static/js/chat.js").read_text(encoding="utf-8")
+RENDERER = (ROOT / "static/js/chatRenderer.js").read_text(encoding="utf-8")
 STYLE = app_css()
-APP = (ROOT / "static/app.js").read_text()
-INDEX = (ROOT / "static/index.html").read_text()
+APP = (ROOT / "static/app.js").read_text(encoding="utf-8")
+INDEX = (ROOT / "static/index.html").read_text(encoding="utf-8")
 
 
 def test_live_interruption_controls_have_visible_resume_labels():

tests/test_queued_message_merge_static.py

@@ -2,7 +2,7 @@ from pathlib import Path
 
 
 ROOT = Path(__file__).resolve().parents[1]
-CHAT = (ROOT / "static/js/chat.js").read_text()
+CHAT = (ROOT / "static/js/chat.js").read_text(encoding="utf-8")
 
 
 def test_queued_stack_is_consumed_as_one_ordered_message():

tests/test_tab_stream_rejoin_static.py

@@ -2,7 +2,7 @@ from pathlib import Path
 
 
 ROOT = Path(__file__).resolve().parents[1]
-CHAT = (ROOT / "static/js/chat.js").read_text()
+CHAT = (ROOT / "static/js/chat.js").read_text(encoding="utf-8")
 
 
 def _visibility_handler() -> str:

tests/test_visual_report_mobile_toolbar.py

@@ -5,7 +5,7 @@ from bs4 import BeautifulSoup
 from src.visual_report import generate_visual_report
 
 
-SOURCE = (Path(__file__).resolve().parents[1] / "src/visual_report.py").read_text()
+SOURCE = (Path(__file__).resolve().parents[1] / "src/visual_report.py").read_text(encoding="utf-8")
 
 
 def test_export_bookmark_is_anchored_and_expands_on_demand():

tests/test_web_search_tool_not_clickable_static.py

@@ -2,8 +2,8 @@ from pathlib import Path
 
 
 ROOT = Path(__file__).resolve().parents[1]
-RENDERER = (ROOT / "static/js/chatRenderer.js").read_text()
-CHAT = (ROOT / "static/js/chat.js").read_text()
+RENDERER = (ROOT / "static/js/chatRenderer.js").read_text(encoding="utf-8")
+CHAT = (ROOT / "static/js/chat.js").read_text(encoding="utf-8")
 
 
 def test_saved_web_search_tool_icon_has_no_action_target():