tests: Always add dummy skipping tests

Just hiding tests that cannot be run does not seem like the best idea.
So add dummy tests that are skipped, to denote that we could test more
than we actually do (even if it is just for drivers that are not
enabled).

tests/meson.build

@@ -16,6 +16,12 @@ envs.set('FP_DRIVERS_WHITELIST', 'virtual_image')
 
 envs.set('NO_AT_BRIDGE', '1')
 
+drivers_tests = [
+    'elan',
+    'vfs5011',
+    'synaptics',
+]
+
 if get_option('introspection')
     envs.prepend('GI_TYPELIB_PATH', join_paths(meson.build_root(), 'libfprint'))
 
@@ -26,18 +32,18 @@ if get_option('introspection')
             env: envs,
             depends: libfprint_typelib,
         )
+    else
+        test('virtual-image',
+            find_program('sh'),
+            args: ['-c', 'exit 77']
+        )
     endif
 
-    drivers_tests = [
-        'elan',
-        'vfs5011',
-        'synaptics',
-    ]
-
     foreach driver_test: drivers_tests
         driver_envs = envs
         driver_envs.set('FP_DRIVERS_WHITELIST', driver_test)
 
+        if driver_test in drivers
             test(driver_test,
                 find_program('umockdev-test.py'),
                 args: join_paths(meson.current_source_dir(), driver_test),
@@ -46,6 +52,25 @@ if get_option('introspection')
                 timeout: 10,
                 depends: libfprint_typelib,
             )
+        else
+            test(driver_test,
+                find_program('sh'),
+                args: ['-c', 'exit 77']
+            )
+        endif
+    endforeach
+else
+    warning('Skipping all driver tests as introspection bindings are missing')
+    test('virtual-image',
+        find_program('sh'),
+        args: ['-c', 'exit 77']
+    )
+
+    foreach driver_test: drivers_tests
+        test(driver_test,
+            find_program('sh'),
+            args: ['-c', 'exit 77']
+        )
     endforeach
 endif