black: fix style check package and flake8 formatting for black

Black will automatically fix a lot of the exceptions we previously allowed for
directives, so we don't need them in our custom `flake8_formatter` anymore.

- [x] remove `E501` (long line) exceptions for directives from `flake8_formatter`,
      as they won't help us now.
- [x] Refine exceptions for long URLs in the `flake8_formatter`.
- [x] Adjust the mock `flake8-package` to exhibit the exceptions we still allow.
- [x] Update style tests for new `flake8-package`.
- [x] Blacken style test.

share/spack/qa/flake8_formatter.py

@@ -21,24 +21,6 @@
             r"^from spack.package import \*$",
             r"^from spack.package_defs import \*$",
         ],
-        # Exempt lines with urls and descriptions from overlong line errors.
-        "E501": [
-            r"^\s*homepage\s*=",
-            r"^\s*url\s*=",
-            r"^\s*git\s*=",
-            r"^\s*svn\s*=",
-            r"^\s*hg\s*=",
-            r"^\s*pypi\s*=",
-            r"^\s*list_url\s*=",
-            r"^\s*version\(",
-            r"^\s*variant\(",
-            r"^\s*provides\(",
-            r"^\s*extends\(",
-            r"^\s*depends_on\(",
-            r"^\s*conflicts\(",
-            r"^\s*resource\(",
-            r"^\s*patch\(",
-        ],
         # Exempt '@when' decorated functions from redefinition errors.
         "F811": [
             r"^\s*@when\(.*\)",
@@ -47,7 +29,7 @@
     # exemptions applied to all files.
     r".py$": {
         "E501": [
-            r"(https?|ftp|file)\:",  # URLs
+            r"(ssh|https?|ftp|file)\:",  # URLs
             r'([\'"])[0-9a-fA-F]{32,}\1',  # long hex checksums
         ]
     },
@@ -58,10 +40,7 @@
 pattern_exemptions = dict(
     (
         re.compile(file_pattern),
-        dict(
-            (code, [re.compile(p) for p in patterns])
-            for code, patterns in error_dict.items()
-        ),
+        dict((code, [re.compile(p) for p in patterns]) for code, patterns in error_dict.items()),
     )
     for file_pattern, error_dict in pattern_exemptions.items()
 )
@@ -105,9 +84,7 @@ def handle(self, error):  # type: (Violation) -> None
         # get list of patterns for this error code
         pats = self.spack_errors.get(error.code, None)
         # if any pattern matches, skip line
-        if pats is not None and any(
-            (pat.search(error.physical_line) for pat in pats)
-        ):
+        if pats is not None and any((pat.search(error.physical_line) for pat in pats)):
             return
 
         # Special F811 handling
@@ -117,16 +94,10 @@ def handle(self, error):  # type: (Violation) -> None
         # https://gitlab.com/pycqa/flake8/issues/583
         # we can only determine if F811 should be ignored given the previous
         # line, so get the previous line and check it
-        if (
-            self.spack_errors.get("F811", False)
-            and error.code == "F811"
-            and error.line_number > 1
-        ):
+        if self.spack_errors.get("F811", False) and error.code == "F811" and error.line_number > 1:
             if self.file_lines is None:
                 if self.filename in {"stdin", "-", "(none)", None}:
-                    self.file_lines = pycodestyle.stdin_get_value().splitlines(
-                        True
-                    )
+                    self.file_lines = pycodestyle.stdin_get_value().splitlines(True)
                 else:
                     self.file_lines = pycodestyle.readlines(self.filename)
             for pat in self.spack_errors["F811"]: