Add new flag '--junit-xml=PATH' to write a junit.xml file (#2326)

This format is used by CI systems. We create a single "test" representing the entire mypy run.

Author: gvanrossum

mypy/main.py

@@ -5,13 +5,15 @@
 import os
 import re
 import sys
+import time
 
 from typing import Any, Dict, List, Mapping, Optional, Set, Tuple
 
 from mypy import build
 from mypy import defaults
 from mypy import git
 from mypy import experiments
+from mypy import util
 from mypy.build import BuildSource, BuildResult, PYTHON_EXTENSIONS
 from mypy.errors import CompileError
 from mypy.options import Options, BuildType
@@ -28,20 +30,25 @@ def main(script_path: str) -> None:
     Args:
         script_path: Path to the 'mypy' script (used for finding data files).
     """
+    t0 = time.time()
     if script_path:
         bin_dir = find_bin_directory(script_path)
     else:
         bin_dir = None
     sources, options = process_options(sys.argv[1:])
-    f = sys.stdout
+    serious = False
     try:
         res = type_check_only(sources, bin_dir, options)
         a = res.errors
     except CompileError as e:
         a = e.messages
         if not e.use_stdout:
-            f = sys.stderr
+            serious = True
+    if options.junit_xml:
+        t1 = time.time()
+        util.write_junit_xml(t1 - t0, serious, a, options.junit_xml)
     if a:
+        f = sys.stderr if serious else sys.stdout
         for m in a:
             f.write(m + '\n')
         sys.exit(1)
@@ -182,6 +189,7 @@ def process_options(args: List[str],
                         "(experimental -- read documentation before using!).  "
                         "Implies --strict-optional.  Has the undesirable side-effect of "
                         "suppressing other errors in non-whitelisted files.")
+    parser.add_argument('--junit-xml', help="write junit.xml to the given file")
     parser.add_argument('--pdb', action='store_true', help="invoke pdb on fatal error")
     parser.add_argument('--show-traceback', '--tb', action='store_true',
                         help="show traceback on fatal error")
@@ -443,6 +451,7 @@ def get_init_file(dir: str) -> Optional[str]:
     'python_version': lambda s: tuple(map(int, s.split('.'))),
     'strict_optional_whitelist': lambda s: s.split(),
     'custom_typing_module': str,
+    'junit_xml': str,
 }
 
 

mypy/options.py

@@ -79,6 +79,9 @@ def __init__(self) -> None:
         # Config file name
         self.config_file = None  # type: Optional[str]
 
+        # Write junit.xml to given file
+        self.junit_xml = None  # type: Optional[str]
+
         # Per-file options (raw)
         self.per_file_options = {}  # type: Dict[str, Dict[str, object]]
 

mypy/util.py

@@ -2,6 +2,7 @@
 
 import re
 import subprocess
+from xml.sax.saxutils import escape
 from typing import TypeVar, List, Tuple, Optional, Sequence
 
 
@@ -113,3 +114,39 @@ def try_find_python2_interpreter() -> Optional[str]:
         except OSError:
             pass
     return None
+
+
+PASS_TEMPLATE = """<?xml version="1.0" encoding="utf-8"?>
+<testsuite errors="0" failures="0" name="mypy" skips="0" tests="1" time="{time:.3f}">
+  <testcase classname="mypy" file="mypy" line="1" name="mypy" time="{time:.3f}">
+  </testcase>
+</testsuite>
+"""
+
+FAIL_TEMPLATE = """<?xml version="1.0" encoding="utf-8"?>
+<testsuite errors="0" failures="1" name="mypy" skips="0" tests="1" time="{time:.3f}">
+  <testcase classname="mypy" file="mypy" line="1" name="mypy" time="{time:.3f}">
+    <failure message="mypy produced messages">{text}</failure>
+  </testcase>
+</testsuite>
+"""
+
+ERROR_TEMPLATE = """<?xml version="1.0" encoding="utf-8"?>
+<testsuite errors="1" failures="0" name="mypy" skips="0" tests="1" time="{time:.3f}">
+  <testcase classname="mypy" file="mypy" line="1" name="mypy" time="{time:.3f}">
+    <error message="mypy produced errors">{text}</error>
+  </testcase>
+</testsuite>
+"""
+
+
+def write_junit_xml(dt: float, serious: bool, messages: List[str], path: str) -> None:
+    """XXX"""
+    if not messages and not serious:
+        xml = PASS_TEMPLATE.format(time=dt)
+    elif not serious:
+        xml = FAIL_TEMPLATE.format(text=escape('\n'.join(messages)), time=dt)
+    else:
+        xml = ERROR_TEMPLATE.format(text=escape('\n'.join(messages)), time=dt)
+    with open(path, 'wb') as f:
+        f.write(xml.encode('utf-8'))