meson: Improve the libnm-core test build file

All variables used in every test have been moved to the start of the
build file.

Generated enum sources variable has been renamed to `enum_sources`
to clearly specify what it is holding.

libnm-core/tests/meson.build

@@ -9,7 +9,7 @@
 
 enum_types = 'nm-core-tests-enum-types'
 
-enum = gnome.mkenums(
+enum_sources = gnome.mkenums(
   enum_types,
   sources: 'test-general-enums.h',
   identifier_prefix: nm_id_prefix,
@@ -17,6 +17,18 @@ enum = gnome.mkenums(
   h_template: enum_types + '.h.template',
 )
 
+deps = [
+  libnm_core_dep,
+  libnm_core_nm_default_dep,
+]
+
+c_flags = [
+  '-DNETWORKMANAGER_COMPILATION_TEST',
+  '-DNETWORKMANAGER_COMPILATION=NM_NETWORKMANAGER_COMPILATION_LIBNM_CORE',
+]
+
+test_cert_dir = join_paths(meson.current_source_dir(), 'certs')
+
 test_units = [
   'test-compare',
   'test-crypto',
@@ -27,24 +39,15 @@ test_units = [
   'test-settings-defaults',
 ]
 
-test_cert_dir = join_paths(meson.current_source_dir(), 'certs')
-
-deps = [
-  libnm_core_dep,
-  libnm_core_nm_default_dep,
-]
-
 foreach test_unit: test_units
   exe = executable(
     'libnm-core-' + test_unit,
-    [test_unit + '.c'] + enum,
+    [test_unit + '.c'] + enum_sources,
     dependencies: deps,
-    c_args: [
+    c_args: c_flags,
-        '-DNETWORKMANAGER_COMPILATION_TEST',
-        '-DNETWORKMANAGER_COMPILATION=NM_NETWORKMANAGER_COMPILATION_LIBNM_CORE',
-      ],
     link_with: libnm_systemd_logging_stub,
   )
+
   test(
     'libnm-core/' + test_unit,
     test_script,