Sanitization of API.

config/config.go

@@ -19,16 +19,20 @@ type cacheEntry struct {
 	contents interface{}
 }
 
+// A Config is a dynamic configuration key lookup mechanism.
 type Config struct {
 	cache         map[string]cacheEntry
 	buildFileList func(map[string]string) []string
 	l             sync.Mutex
 }
 
-func New() *Config {
+// New takes a file list builder and returns a new instance of Config.
+//
+// The instance is ready to use.
+func New(f func(map[string]string) []string) *Config {
 	var c Config
 	c.cache = make(map[string]cacheEntry)
-	c.l.Lock() // Lock until we have a proper file list builder
+	c.buildFileList = f
 	return &c
 }
 
@@ -77,15 +81,6 @@ func (c *Config) lookupvar(key, path string) interface{} {
 	return c.cache[path].contents.(map[string]interface{})[key]
 }
 
-// SetFileListBuilder registers file list builder function.
-//
-// Registered function takes context (key-value map[string]string) as the only
-// argument and return a slice of strings - file paths.
-func (c *Config) SetFileListBuilder(f func(map[string]string) []string) {
-	c.buildFileList = f
-	c.l.Unlock()
-}
-
 // Lookup searches for requested configuration key in file list built using
 // context.
 func (c *Config) Lookup(context map[string]string, key string) interface{} {

config/config_test.go

@@ -237,12 +237,10 @@ func TestLookupvarConditions(t *testing.T) {
 	}
 }
 
-var c *Config = New()
-var c2 *Config = New()
+var c *Config = New(configLookupHelper)
+var c2 *Config = New(complicatedLookupHelper)
 
 func TestMain(m *testing.M) {
-	c.SetFileListBuilder(configLookupHelper)
-	c2.SetFileListBuilder(complicatedLookupHelper)
 	log.SetOutput(ioutil.Discard)
 	os.Exit(m.Run())
 }