Move the python imports test out of the build test module

The build test is designed to run with frozen calibre, where the
source files may not be available. So run it only as part of
the setup test suite.

setup/test.py

@@ -2,15 +2,57 @@
 # vim:fileencoding=utf-8
 # License: GPLv3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 
-from __future__ import (unicode_literals, division, absolute_import,
+from __future__ import absolute_import, division, print_function, unicode_literals
-                        print_function)
+
+import os
 import unittest
 
-from setup import Command
+from setup import Command, islinux, isosx, iswindows, SRC
 
 TEST_MODULES = frozenset('srv db polish opf css docx cfi matcher icu smartypants build misc dbcli'.split())
 
 
+class TestImports(unittest.TestCase):
+
+    def test_import_of_all_python_modules(self):
+        import importlib
+        exclude_modules = {'calibre.gui2.dbus_export.demo', 'calibre.gui2.dbus_export.gtk'}
+        exclude_packages = {'calibre.devices.mtp.unix.upstream'}
+        if not iswindows:
+            exclude_modules |= {'calibre.utils.iphlpapi', 'calibre.utils.open_with.windows', 'calibre.devices.winusb'}
+            exclude_packages |= {'calibre.utils.winreg'}
+        if not isosx:
+            exclude_modules.add('calibre.utils.open_with.osx')
+        if not islinux:
+            exclude_modules |= {
+                    'calibre.utils.dbus_service', 'calibre.linux',
+                    'calibre.utils.linux_trash', 'calibre.utils.open_with.linux',
+                    'calibre.gui2.linux_file_dialogs'
+            }
+            exclude_packages.add('calibre.gui2.dbus_export')
+        base = os.path.join(SRC, 'calibre')
+        import_base = os.path.dirname(base)
+        count = 0
+        for root, dirs, files in os.walk(base):
+            for d in dirs:
+                if not os.path.isfile(os.path.join(root, d, '__init__.py')):
+                    dirs.remove(d)
+            for fname in files:
+                module_name, ext = os.path.splitext(fname)
+                if ext != '.py':
+                    continue
+                path = os.path.join(root, module_name)
+                relpath = os.path.relpath(path, import_base).replace(os.sep, '/')
+                full_module_name = '.'.join(relpath.split('/'))
+                if full_module_name.endswith('.__init__'):
+                    full_module_name = full_module_name.rpartition('.')[0]
+                if full_module_name in exclude_modules or ('.' in full_module_name and full_module_name.rpartition('.')[0] in exclude_packages):
+                    continue
+                importlib.import_module(full_module_name)
+                count += 1
+        self.assertGreater(count, 1000)
+
+
 def find_tests(which_tests=None):
     ans = []
     a = ans.append
@@ -76,6 +118,7 @@ def find_tests(which_tests=None):
         a(find_tests())
         from calibre.library.comments import find_tests
         a(find_tests())
+        a(unittest.defaultTestLoader.loadTestsFromTestCase(TestImports))
     if ok('dbcli'):
         from calibre.db.cli.tests import find_tests
         a(find_tests())

src/calibre/test_build.py

@@ -73,44 +73,6 @@ class BuildTest(unittest.TestCase):
         from html5_parser import parse
         parse('<p>xxx')
 
-    def test_import_of_all_python_modules(self):
-        import importlib
-        exclude_modules = {'calibre.gui2.dbus_export.demo', 'calibre.gui2.dbus_export.gtk'}
-        exclude_packages = {'calibre.devices.mtp.unix.upstream'}
-        if not iswindows:
-            exclude_modules |= {'calibre.utils.iphlpapi', 'calibre.utils.open_with.windows', 'calibre.devices.winusb'}
-            exclude_packages |= {'calibre.utils.winreg'}
-        if not isosx:
-            exclude_modules.add('calibre.utils.open_with.osx')
-        if not islinux:
-            exclude_modules |= {
-                    'calibre.utils.dbus_service', 'calibre.linux',
-                    'calibre.utils.linux_trash', 'calibre.utils.open_with.linux',
-                    'calibre.gui2.linux_file_dialogs'
-            }
-            exclude_packages.add('calibre.gui2.dbus_export')
-        base = os.path.dirname(__file__)
-        import_base = os.path.dirname(base)
-        count = 0
-        for root, dirs, files in os.walk(base):
-            for d in dirs:
-                if not os.path.isfile(os.path.join(root, d, '__init__.py')):
-                    dirs.remove(d)
-            for fname in files:
-                module_name, ext = os.path.splitext(fname)
-                if ext != '.py':
-                    continue
-                path = os.path.join(root, module_name)
-                relpath = os.path.relpath(path, import_base).replace(os.sep, '/')
-                full_module_name = '.'.join(relpath.split('/'))
-                if full_module_name.endswith('.__init__'):
-                    full_module_name = full_module_name.rpartition('.')[0]
-                if full_module_name in exclude_modules or ('.' in full_module_name and full_module_name.rpartition('.')[0] in exclude_packages):
-                    continue
-                importlib.import_module(full_module_name)
-                count += 1
-        self.assertGreater(count, 1000)
-
     def test_plugins(self):
         exclusions = set()
         if is_ci: