[PATCH v2 3/6] iotests/linters: check mypy files all at once

[John Snow <jsnow@redhat.com>]

We can circumvent the '__main__' redefinition problem by passing
--scripts-are-modules. Take mypy out of the loop per-filename and check
everything in one go: it's quite a bit faster.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
---
 tests/qemu-iotests/297 | 44 +++++++++++++++++++-----------------------
 1 file changed, 20 insertions(+), 24 deletions(-)

diff --git a/tests/qemu-iotests/297 b/tests/qemu-iotests/297
index 467b712280e..91ec34d9521 100755
--- a/tests/qemu-iotests/297
+++ b/tests/qemu-iotests/297
@@ -74,32 +74,28 @@ def run_linters():
     print('=== mypy ===')
     sys.stdout.flush()
 
-    # We have to call mypy separately for each file.  Otherwise, it
-    # will interpret all given files as belonging together (i.e., they
-    # may not both define the same classes, etc.; most notably, they
-    # must not both define the __main__ module).
     env['MYPYPATH'] = env['PYTHONPATH']
-    for filename in files:
-        p = subprocess.run(('mypy',
-                            '--warn-unused-configs',
-                            '--disallow-subclassing-any',
-                            '--disallow-any-generics',
-                            '--disallow-incomplete-defs',
-                            '--disallow-untyped-decorators',
-                            '--no-implicit-optional',
-                            '--warn-redundant-casts',
-                            '--warn-unused-ignores',
-                            '--no-implicit-reexport',
-                            '--namespace-packages',
-                            filename),
-                           env=env,
-                           check=False,
-                           stdout=subprocess.PIPE,
-                           stderr=subprocess.STDOUT,
-                           universal_newlines=True)
+    p = subprocess.run(('mypy',
+                        '--warn-unused-configs',
+                        '--disallow-subclassing-any',
+                        '--disallow-any-generics',
+                        '--disallow-incomplete-defs',
+                        '--disallow-untyped-decorators',
+                        '--no-implicit-optional',
+                        '--warn-redundant-casts',
+                        '--warn-unused-ignores',
+                        '--no-implicit-reexport',
+                        '--namespace-packages',
+                        '--scripts-are-modules',
+                        *files),
+                       env=env,
+                       check=False,
+                       stdout=subprocess.PIPE,
+                       stderr=subprocess.STDOUT,
+                       universal_newlines=True)
 
-        if p.returncode != 0:
-            print(p.stdout)
+    if p.returncode != 0:
+        print(p.stdout)
 
 
 for linter in ('pylint-3', 'mypy'):
-- 
2.31.1