Conformance: fix issues running on Windows (#1969)

Author: Andrej730

Diff for: conformance/README.md

@@ -60,7 +60,7 @@ To run the conformance test suite:
 * Switch to the `conformance` subdirectory and install all dependencies (`pip install -r requirements.txt`).
 * Switch to the `src` subdirectory and run `python main.py`.
 
-Note that some type checkers may not run on some platforms. For example, pytype cannot be installed on Windows. If a type checker fails to install, tests will be skipped for that type checker.
+Note that some type checkers may not run on some platforms. If a type checker fails to install, tests will be skipped for that type checker.
 
 ## Reporting Conformance Results
 

Diff for: conformance/requirements.txt

@@ -5,4 +5,4 @@ pyright
 mypy
 pip
 pyre-check
-pytype; platform_system != "Windows"
+pytype

Diff for: conformance/src/main.py

@@ -67,7 +67,7 @@ def f(): pass  # E[final]
             {"final": [3, 4]}
         )
     """
-    with open(test_case, "r") as f:
+    with open(test_case, "r", encoding="utf-8") as f:
         lines = f.readlines()
     output: dict[int, tuple[int, int]] = {}
     groups: dict[str, list[int]] = {}

Diff for: conformance/src/type_checker.py

@@ -3,7 +3,6 @@
 """
 
 from abc import ABC, abstractmethod
-from curses.ascii import isspace
 import json
 from pathlib import Path
 import os
@@ -114,7 +113,7 @@ def run_tests(self, test_files: Sequence[str]) -> dict[str, str]:
             "--enable-error-code",
             "deprecated",
         ]
-        proc = run(command, stdout=PIPE, text=True)
+        proc = run(command, stdout=PIPE, text=True, encoding="utf-8")
         lines = proc.stdout.split("\n")
 
         # Add results to a dictionary keyed by the file name.
@@ -174,7 +173,7 @@ def get_version(self) -> str:
 
     def run_tests(self, test_files: Sequence[str]) -> dict[str, str]:
         command = [sys.executable, "-m", "pyright", ".", "--outputjson"]
-        proc = run(command, stdout=PIPE, text=True)
+        proc = run(command, stdout=PIPE, text=True, encoding="utf-8")
         output_json = json.loads(proc.stdout)
         diagnostics = output_json["generalDiagnostics"]
 
@@ -253,7 +252,7 @@ def get_version(self) -> str:
         return version
 
     def run_tests(self, test_files: Sequence[str]) -> dict[str, str]:
-        proc = run(["pyre", "check"], stdout=PIPE, text=True)
+        proc = run(["pyre", "check"], stdout=PIPE, text=True, encoding="utf-8")
         lines = proc.stdout.split("\n")
 
         # Add results to a dictionary keyed by the file name.
@@ -325,7 +324,7 @@ def run_tests(self, test_files: Sequence[str]) -> dict[str, str]:
             if not fi.endswith(".py"):
                 continue
             options.tweak(input=fi)
-            with open(fi, "r") as test_file:
+            with open(fi, "r", encoding="utf-8") as test_file:
                 src = test_file.read()
             try:
                 analysis: pytype_analyze.Analysis = pytype_io.check_py(