RuntimeError: ruff format failed (exit code 2): error: Failed to read: stream did not contain valid UTF-8

[vashek]

Bug started in 0.18.0 (this didn't occur in 0.17.2 -- although the graphqlschema command didn't work at all so hard to say).

Running on the Shopify schema (https://{shopname}.myshopify.com/admin/api/2026-01/graphql.json), client generator fails with:

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\devel\shop\.venv\Scripts\ariadne-codegen.EXE\__main__.py", line 7, in <module>
  File "C:\devel\shop\.venv\Lib\site-packages\click\core.py", line 1485, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\click\core.py", line 1406, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\click\core.py", line 1269, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\click\core.py", line 824, in invoke
    return callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\main.py", line 37, in main
    client(config_dict)
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\main.py", line 87, in client
    generated_files = package_generator.generate()
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\client_generators\package.py", line 163, in generate
    self._generate_input_types()
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\client_generators\package.py", line 320, in _generate_input_types
    code = self._add_comments_to_code(ast_to_str(module), self.schema_source)
                                      ^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\utils.py", line 115, in ast_to_str
    return _format_code(code, remove_unused_imports=remove_unused_imports)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\utils.py", line 85, in _format_code
    raise RuntimeError(
RuntimeError: ruff format failed (exit code 2): error: Failed to read: stream did not contain valid UTF-8

Also, with target_file_path = "shopify_schema.py", running ariadne-codegen graphqlschema fails with this, which I presume is related:

Selected strategy: Strategy.GRAPHQL_SCHEMA
Using schema from https://<shopname>.myshopify.com/admin/api/2026-01/graphql.json
Introspection settings: descriptions=true, input_value_deprecation=true, specified_by_url=true, schema_description=true, directive_is_repeatable=true, input_object_one_of=true
Saving graphql schema to: shopify_schema.py
Using schema as variable name for schema.
Using type_map as variable name for type map.
Plugins to use: ariadne_codegen.contrib.extract_operations.ExtractOperationsPlugin
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\devel\shop\.venv\Scripts\ariadne-codegen.EXE\__main__.py", line 7, in <module>
  File "C:\devel\shop\.venv\Lib\site-packages\click\core.py", line 1485, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\click\core.py", line 1406, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\click\core.py", line 1269, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\click\core.py", line 824, in invoke
    return callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\main.py", line 40, in main
    graphql_schema(config_dict)
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\main.py", line 117, in graphql_schema
    generate_graphql_schema_python_file(
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\graphql_schema_generators\schema.py", line 42, in generate_graphql_schema_python_file
    code = ast_to_str(module)
           ^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\utils.py", line 115, in ast_to_str
    return _format_code(code, remove_unused_imports=remove_unused_imports)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\devel\shop\.venv\Lib\site-packages\ariadne_codegen\utils.py", line 65, in _format_code
    result = subprocess.run(
             ^^^^^^^^^^^^^^^
  File "C:\Users\dvorak\AppData\Local\Python\pythoncore-3.12-64\Lib\subprocess.py", line 550, in run
    stdout, stderr = process.communicate(input, timeout=timeout)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\dvorak\AppData\Local\Python\pythoncore-3.12-64\Lib\subprocess.py", line 1209, in communicate
    stdout, stderr = self._communicate(input, endtime, timeout)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\dvorak\AppData\Local\Python\pythoncore-3.12-64\Lib\subprocess.py", line 1622, in _communicate
    self._stdin_write(input)
  File "C:\Users\dvorak\AppData\Local\Python\pythoncore-3.12-64\Lib\subprocess.py", line 1143, in _stdin_write
    self.stdin.write(input)
  File "C:\Users\dvorak\AppData\Local\Python\pythoncore-3.12-64\Lib\encodings\cp1252.py", line 19, in encode
    return codecs.charmap_encode(input,self.errors,encoding_table)[0]
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeEncodeError: 'charmap' codec can't encode characters in position 779015-779016: character maps to <undefined>