Major fixes and new features

venv/lib/python3.12/site-packages/mypy/test/testpythoneval.py

@@ -0,0 +1,116 @@
+"""Test cases for running mypy programs using a Python interpreter.
+
+Each test case type checks a program then runs it using Python. The
+output (stdout) of the program is compared to expected output. Type checking
+uses full builtins and other stubs.
+
+Note: Currently Python interpreter paths are hard coded.
+
+Note: These test cases are *not* included in the main test suite, as including
+      this suite would slow down the main suite too much.
+"""
+
+from __future__ import annotations
+
+import os
+import os.path
+import re
+import subprocess
+import sys
+from tempfile import TemporaryDirectory
+
+from mypy import api
+from mypy.defaults import PYTHON3_VERSION
+from mypy.test.config import test_temp_dir
+from mypy.test.data import DataDrivenTestCase, DataSuite
+from mypy.test.helpers import assert_string_arrays_equal, split_lines
+
+# Path to Python 3 interpreter
+python3_path = sys.executable
+program_re = re.compile(r"\b_program.py\b")
+
+
+class PythonEvaluationSuite(DataSuite):
+    files = ["pythoneval.test", "pythoneval-asyncio.test"]
+    cache_dir = TemporaryDirectory()
+
+    def run_case(self, testcase: DataDrivenTestCase) -> None:
+        test_python_evaluation(testcase, os.path.join(self.cache_dir.name, ".mypy_cache"))
+
+
+def test_python_evaluation(testcase: DataDrivenTestCase, cache_dir: str) -> None:
+    """Runs Mypy in a subprocess.
+
+    If this passes without errors, executes the script again with a given Python
+    version.
+    """
+    assert testcase.old_cwd is not None, "test was not properly set up"
+    # We must enable site packages to get access to installed stubs.
+    mypy_cmdline = [
+        "--show-traceback",
+        "--no-silence-site-packages",
+        "--no-error-summary",
+        "--hide-error-codes",
+        "--allow-empty-bodies",
+        "--force-uppercase-builtins",
+    ]
+    interpreter = python3_path
+    mypy_cmdline.append(f"--python-version={'.'.join(map(str, PYTHON3_VERSION))}")
+
+    m = re.search("# flags: (.*)$", "\n".join(testcase.input), re.MULTILINE)
+    if m:
+        additional_flags = m.group(1).split()
+        for flag in additional_flags:
+            if flag.startswith("--python-version="):
+                targetted_python_version = flag.split("=")[1]
+                targetted_major, targetted_minor = targetted_python_version.split(".")
+                if (int(targetted_major), int(targetted_minor)) > (
+                    sys.version_info.major,
+                    sys.version_info.minor,
+                ):
+                    return
+        mypy_cmdline.extend(additional_flags)
+
+    # Write the program to a file.
+    program = "_" + testcase.name + ".py"
+    program_path = os.path.join(test_temp_dir, program)
+    mypy_cmdline.append(program_path)
+    with open(program_path, "w", encoding="utf8") as file:
+        for s in testcase.input:
+            file.write(f"{s}\n")
+    mypy_cmdline.append(f"--cache-dir={cache_dir}")
+    output = []
+    # Type check the program.
+    out, err, returncode = api.run(mypy_cmdline)
+    # split lines, remove newlines, and remove directory of test case
+    for line in (out + err).splitlines():
+        if line.startswith(test_temp_dir + os.sep):
+            output.append(line[len(test_temp_dir + os.sep) :].rstrip("\r\n"))
+        else:
+            # Normalize paths so that the output is the same on Windows and Linux/macOS.
+            line = line.replace(test_temp_dir + os.sep, test_temp_dir + "/")
+            output.append(line.rstrip("\r\n"))
+    if returncode > 1 and not testcase.output:
+        # Either api.run() doesn't work well in case of a crash, or pytest interferes with it.
+        # Tweak output to prevent tests with empty expected output to pass in case of a crash.
+        output.append("!!! Mypy crashed !!!")
+    if returncode == 0 and not output:
+        # Execute the program.
+        proc = subprocess.run(
+            [interpreter, "-Wignore", program], cwd=test_temp_dir, capture_output=True
+        )
+        output.extend(split_lines(proc.stdout, proc.stderr))
+    # Remove temp file.
+    os.remove(program_path)
+    for i, line in enumerate(output):
+        if os.path.sep + "typeshed" + os.path.sep in line:
+            output[i] = line.split(os.path.sep)[-1]
+    assert_string_arrays_equal(
+        adapt_output(testcase), output, f"Invalid output ({testcase.file}, line {testcase.line})"
+    )
+
+
+def adapt_output(testcase: DataDrivenTestCase) -> list[str]:
+    """Translates the generic _program.py into the actual filename."""
+    program = "_" + testcase.name + ".py"
+    return [program_re.sub(program, line) for line in testcase.output]