Recursively load themes

Themes (other than the default theme) can specify a `parent-name` in the
json file. This theme will be used as a base for the theme. Events and
profiles of the children override those in the parents.

For this we move the lookup code into it's separate class and also add
tests.

Closes: #38

tests/meson.build

@@ -11,7 +11,7 @@ test_env.set('MALLOC_CHECK_', '2')
 test_env.set('XDG_CONFIG_HOME', meson.current_source_dir())
 test_env.set('XDG_CONFIG_DIRS', meson.current_source_dir())
 
-# Shared lfbrary Unit tests
+# Shared library Unit tests
 
 test_lfb_cflags = [
   '-DTEST_APP_ID="org.sigxcpu.feedbackd_test"',
@@ -52,10 +52,13 @@ endforeach
 # Daemon Unit tests
 if get_option('daemon')
 
+test_env_fbd = test_env
+test_env_fbd.set('XDG_DATA_DIRS', meson.current_source_dir() / 'data' / 'xdg-data')
+
 test_fbd_cflags = [
     '-DTEST_APP_ID="org.sigxcpu.feedbackd_test"',
     '-DTEST_DATA_DIR="@0@"'.format(join_paths(meson.current_source_dir(), 'data')),
-]
+  ]
 
 test_fbd_link_args = [
   '-fPIC',
@@ -69,6 +72,7 @@ fbd_tests = [
   'fbd-feedback-profile',
   'fbd-feedback-theme',
   'fbd-event',
+  'fbd-theme-expander',
 ]
 
 foreach test : fbd_tests
@@ -79,7 +83,7 @@ foreach test : fbd_tests
                  link_args : test_fbd_link_args,
 		 include_directories : fbd_inc,
                  dependencies : test_fbd_deps)
-  test(test, t, env : test_env)
+  test(test, t, env : test_env_fbd)
 endforeach