Tighten regex for output assertion parsing (#157)

* Tighten regex for output assertion parsing

The `severity` group was permissive enough to also capture parts of
the message text if that contained any colons. Update it to only capture
(ASCII) words, and update preceding groups to match at least 1
character.

Fixes #155

---------

Co-authored-by: sobolevn <[email protected]>

Author: mjpieters

pytest_mypy_plugins/tests/test-regex-assertions.yml

@@ -54,3 +54,22 @@
   main: |
     a = 'hello'
     reveal_type(a)  # NR: .*banana.*
+
+- case: regex_against_callable_comment
+  main: |
+    from typing import Set, Union
+
+    def foo(bar: str, ham: int = 42) -> Set[Union[str, int]]:
+      return {bar, ham}
+    reveal_type(foo)  # NR: Revealed type is "def \(bar: builtins\.str, ham: builtins\.int =\) -> .*"
+
+- case: regex_against_callable_out
+  regex: yes
+  main: |
+    from typing import Set, Union
+
+    def foo(bar: str, ham: int = 42) -> Set[Union[str, int]]:
+      return {bar, ham}
+    reveal_type(foo)
+  out: |
+    main:5: note: Revealed type is "def \(bar: builtins\.str, ham: builtins\.int =\) -> .*"

pytest_mypy_plugins/utils.py

@@ -326,7 +326,7 @@ def extract_output_matchers_from_out(out: str, params: Mapping[str, Any], regex:
     lines = render_template(out, params).split("\n")
     for line in lines:
         match = re.search(
-            r"^(?P<fname>.*):(?P<lnum>\d*): (?P<severity>.*):((?P<col>\d+):)? (?P<message>.*)$", line.strip()
+            r"^(?P<fname>.+):(?P<lnum>\d+): (?P<severity>[A-Za-z]+):((?P<col>\d+):)? (?P<message>.*)$", line.strip()
         )
         if match:
             if match.group("severity") == "E":