unittests: Replace use of from X import * with explicit imports

`*` imports that do not also make use of `__all__` are dangerous, they
allow things to leak in that weren't inteded. An example of this is that
we use `unittest` from the `*` import in several places. This not only
makes the code cleaner, but helps analysis tools like mypy and flake8 to
generate better warnings.

unittests/allplatformstests.py

@@ -68,7 +68,10 @@ from run_tests import (
 )
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import (
+    skip_if_not_language, skipIfNoExecutable, skip_if_no_cmake,
+    skipIfNoPkgconfig, IS_CI, chdir, get_rpath, skip_if_not_base_option,
+)
 
 if T.TYPE_CHECKING:
     from mesonbuild.compilers.compilers import Language
@@ -266,7 +269,6 @@ class AllPlatformTests(BasePlatformTests):
                 with open(os.path.join(self.builddir, header), encoding='utf-8') as f:
                     meson_header = f.read()
 
-                cmake_header_path = os.path.join(cmake_builddir, header)
                 with open(os.path.join(cmake_builddir, header), encoding='utf-8') as f:
                     cmake_header = f.read()
 
@@ -5545,7 +5547,7 @@ class AllPlatformTests(BasePlatformTests):
     @skipIfNoExecutable('rustdoc')
     def test_rustdoc(self) -> None:
         if self.backend is not Backend.ninja:
-            raise unittest.SkipTest('Rust is only supported with ninja currently')
+            raise SkipTest('Rust is only supported with ninja currently')
         try:
             with tempfile.TemporaryDirectory() as tmpdir:
                 testdir = os.path.join(tmpdir, 'a')
@@ -5563,7 +5565,7 @@ class AllPlatformTests(BasePlatformTests):
     @skipIfNoExecutable('clippy-driver')
     def test_rust_clippy(self) -> None:
         if self.backend is not Backend.ninja:
-            raise unittest.SkipTest('Rust is only supported with ninja currently')
+            raise SkipTest('Rust is only supported with ninja currently')
         # When clippy is used, we should get an exception since a variable named
         # "foo" is used, but is on our denylist
         testdir = os.path.join(self.rust_test_dir, '1 basic')
@@ -5581,7 +5583,7 @@ class AllPlatformTests(BasePlatformTests):
     @skipIfNoExecutable('clippy-driver')
     def test_rust_clippy_as_rustc(self) -> None:
         if self.backend is not Backend.ninja:
-            raise unittest.SkipTest('Rust is only supported with ninja currently')
+            raise SkipTest('Rust is only supported with ninja currently')
         # When clippy is used, we should get an exception since a variable named
         # "foo" is used, but is on our denylist
         testdir = os.path.join(self.rust_test_dir, '1 basic')
@@ -5594,14 +5596,14 @@ class AllPlatformTests(BasePlatformTests):
     @skip_if_not_language('rust')
     def test_rust_test_warnings(self) -> None:
         if self.backend is not Backend.ninja:
-            raise unittest.SkipTest('Rust is only supported with ninja currently')
+            raise SkipTest('Rust is only supported with ninja currently')
         testdir = os.path.join(self.rust_test_dir, '9 unit tests')
         self.init(testdir, extra_args=['--fatal-meson-warnings'])
 
     @skip_if_not_language('rust')
     def test_rust_rlib_linkage(self) -> None:
         if self.backend is not Backend.ninja:
-            raise unittest.SkipTest('Rust is only supported with ninja currently')
+            raise SkipTest('Rust is only supported with ninja currently')
         template = textwrap.dedent('''\
                 use std::process::exit;
 
@@ -5632,7 +5634,7 @@ class AllPlatformTests(BasePlatformTests):
     @skip_if_not_language('rust')
     def test_bindgen_drops_invalid(self) -> None:
         if self.backend is not Backend.ninja:
-            raise unittest.SkipTest('Rust is only supported with ninja currently')
+            raise SkipTest('Rust is only supported with ninja currently')
         testdir = os.path.join(self.rust_test_dir, '12 bindgen')
         env = get_fake_env(testdir, self.builddir, self.prefix)
         cc = detect_c_compiler(env, MachineChoice.HOST)
@@ -5643,7 +5645,7 @@ class AllPlatformTests(BasePlatformTests):
         elif cc.get_id() == 'msvc':
             bad_arg = '/fastfail'
         else:
-            raise unittest.SkipTest('Test only supports GCC and MSVC')
+            raise SkipTest('Test only supports GCC and MSVC')
         self.init(testdir, extra_args=[f"-Dc_args=['-DCMD_ARG', '{bad_arg}']"])
         intro = self.introspect(['--targets'])
         for i in intro:

unittests/darwintests.py

@@ -1,11 +1,14 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright 2016-2021 The Meson development team
 
+from __future__ import annotations
+
 import subprocess
 import re
 import os
 import platform
 import unittest
+import typing as T
 
 from mesonbuild.mesonlib import (
     MachineChoice, is_osx, version_compare
@@ -20,7 +23,7 @@ from run_tests import (
 )
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import skip_if_not_language, skipIfNoPkgconfig
 
 @unittest.skipUnless(is_osx(), "requires Darwin")
 class DarwinTests(BasePlatformTests):

unittests/datatests.py

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright 2016-2021 The Meson development team
 
+import os
 import re
 import unittest
 from itertools import chain
@@ -31,7 +32,7 @@ from run_tests import (
     FakeBuild, get_fake_env
 )
 
-from .helpers import *
+from .helpers import is_tarball
 
 @unittest.skipIf(is_tarball(), 'Skipping because this is a tarball release')
 class DataTests(unittest.TestCase):

unittests/failuretests.py

@@ -25,7 +25,7 @@ from run_tests import (
 )
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import skipIfNoPkgconfigDep
 
 @contextmanager
 def no_pkgconfig():

unittests/internaltests.py

@@ -53,7 +53,7 @@ from mesonbuild import utils
 
 from run_tests import get_fake_env, get_fake_options
 
-from .helpers import *
+from .helpers import IS_CI, chdir, skipIfNoPkgconfig
 
 class InternalTests(unittest.TestCase):
 
@@ -1080,7 +1080,6 @@ Thread model: posix'''), '21.9.0')
             return
 
         with tempfile.TemporaryDirectory() as tmpdir:
-            pkgbin = ExternalProgram('pkg-config', command=['pkg-config'], silent=True)
             env = get_fake_env()
             compiler = detect_c_compiler(env, MachineChoice.HOST)
             env.coredata.compilers.host = {'c': compiler}

unittests/linuxcrosstests.py

@@ -15,7 +15,9 @@ from mesonbuild.mesonlib import MesonException
 
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import (
+    skipIfNoPkgconfig, skipIfNoExecutable
+)
 
 class BaseLinuxCrossTests(BasePlatformTests):
     # Don't pass --libdir when cross-compiling. We have tests that

unittests/linuxliketests.py

@@ -50,7 +50,15 @@ from run_tests import (
 )
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import (
+    skip_if_not_language, skip_if_not_base_option, get_rpath,
+    skipIfNoExecutable, skipIfNoPkgconfig, skipIfNoPkgconfigDep,
+    chdir, get_soname
+)
+
+if T.TYPE_CHECKING:
+    from mesonbuild.compilers import Compiler
+
 
 def _prepend_pkg_config_path(path: str) -> str:
     """Prepend a string value to pkg_config_path

unittests/machinefiletests.py

@@ -41,7 +41,9 @@ from run_tests import (
 )
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import (
+    skip_if_not_language, skipIfNoExecutable, get_classpath, skip_if_env_set
+)
 
 @functools.lru_cache()
 def is_real_gnu_compiler(path):
@@ -314,7 +316,7 @@ class NativeFileTests(BasePlatformTests):
             self.helper_for_compiler('objc', cb)
         except mesonlib.EnvironmentException as e:
             if 'GCC was not built with support for objective-c' in str(e):
-                raise unittest.SkipTest("GCC doesn't support objective-c, test cannot run")
+                raise SkipTest("GCC doesn't support objective-c, test cannot run")
             raise
 
     @skip_if_not_language('objcpp')
@@ -332,7 +334,7 @@ class NativeFileTests(BasePlatformTests):
             self.helper_for_compiler('objcpp', cb)
         except mesonlib.EnvironmentException as e:
             if 'GCC was not built with support for objective-c++' in str(e):
-                raise unittest.SkipTest("G++ doesn't support objective-c++, test cannot run")
+                raise SkipTest("G++ doesn't support objective-c++, test cannot run")
             raise
 
     @skip_if_not_language('d')

unittests/optiontests.py

@@ -1,8 +1,12 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright 2024 Meson project contributors
 
-from mesonbuild.options import *
+from mesonbuild.options import (
+    OptionStore, OptionKey, UserStringOption, UserStringArrayOption,
+    UserComboOption, UserBooleanOption,
+)
 from mesonbuild.envconfig import MachineInfo
+from mesonbuild.utils.universal import MesonException, MachineChoice
 
 import os
 import unittest
@@ -236,7 +240,6 @@ class OptionTests(unittest.TestCase):
         optstore = OptionStore(False)
         name = 'cpp_std'
         sub_name = 'sub'
-        sub2_name = 'sub2'
         top_value = 'c++11'
         aug_value = 'c++23'
         set_value = 'c++20'

unittests/platformagnostictests.py

@@ -15,7 +15,7 @@ from unittest import skipIf, SkipTest
 from pathlib import Path
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import skip_if_not_language, IS_CI
 from mesonbuild.mesonlib import EnvironmentVariables, ExecutableSerialisation, MesonException, is_linux, python_command, windows_proof_rmtree
 from mesonbuild.mformat import Formatter, match_path
 from mesonbuild.optinterpreter import OptionInterpreter, OptionException
@@ -138,7 +138,7 @@ class PlatformAgnosticTests(BasePlatformTests):
     def check_connectivity(self):
         import urllib
         try:
-            with urllib.request.urlopen('https://wrapdb.mesonbuild.com') as p:
+            with urllib.request.urlopen('https://wrapdb.mesonbuild.com'):
                 pass
         except urllib.error.URLError as e:
             self.skipTest('No internet connectivity: ' + str(e))
@@ -474,7 +474,7 @@ class PlatformAgnosticTests(BasePlatformTests):
         testdir = self.copy_srcdir(os.path.join(self.common_test_dir, '40 options'))
         self.init(testdir)
         self.assertEqual(self.getconf('neg_int_opt'), -3)
-        with self.assertRaises(subprocess.CalledProcessError) as e:
+        with self.assertRaises(subprocess.CalledProcessError):
             self.init(testdir, extra_args=['--reconfigure', '-Dneg_int_opt=0'])
         self.assertEqual(self.getconf('neg_int_opt'), -3)
         self.init(testdir, extra_args=['--reconfigure', '-Dneg_int_opt=-2'])

unittests/pythontests.py

@@ -9,7 +9,7 @@ from run_tests import (
 
 from .allplatformstests import git_init
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import get_fake_env
 
 from mesonbuild.compilers.detect import detect_c_compiler
 from mesonbuild.mesonlib import MachineChoice, TemporaryDirectoryWinProof, is_windows

unittests/subprojectscommandtests.py

@@ -15,7 +15,7 @@ from mesonbuild.mesonlib import (
 
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import skipIfNoExecutable
 
 class SubprojectsCommandTests(BasePlatformTests):
     def setUp(self):

unittests/windowstests.py

@@ -33,7 +33,9 @@ from run_tests import (
 )
 
 from .baseplatformtests import BasePlatformTests
-from .helpers import *
+from .helpers import (
+    get_path_without_cmd, skip_if_not_base_option, IS_CI, skip_if_not_language,
+)
 
 @skipUnless(is_windows() or is_cygwin(), "requires Windows (or Windows via Cygwin)")
 class WindowsTests(BasePlatformTests):
@@ -459,7 +461,7 @@ class WindowsTests(BasePlatformTests):
         self.init(testdir, extra_args=['-Dtest-failure=true'])
         self.assertRaises(subprocess.CalledProcessError, self.build)
 
-    @unittest.skipIf(is_cygwin(), "Needs visual studio")
+    @skipIf(is_cygwin(), "Needs visual studio")
     def test_vsenv_option(self):
         if self.backend is not Backend.ninja:
             raise SkipTest('Only ninja backend is valid for test')