Move reflection functions to separate file

Author: jwilder

docker-gen.go

@@ -16,7 +16,7 @@ import (
 	"os/exec"
 	"os/signal"
 	"path/filepath"
-	"reflect"
+
 	"strings"
 	"syscall"
 	"text/template"
@@ -72,33 +72,8 @@ func (c *ConfigFile) filterWatches() ConfigFile {
 	}
 }
 
-func deepGet(item interface{}, path string) interface{} {
-	if path == "" {
-		return item
-	}
-
-	parts := strings.Split(path, ".")
-	itemValue := reflect.ValueOf(item)
-
-	if len(parts) > 0 {
-		switch itemValue.Kind() {
-		case reflect.Struct:
-			fieldValue := itemValue.FieldByName(parts[0])
-			if fieldValue.IsValid() {
-				return deepGet(fieldValue.Interface(), strings.Join(parts[1:], "."))
-			}
-		case reflect.Map:
-			mapValue := itemValue.MapIndex(reflect.ValueOf(parts[0]))
-			if mapValue.IsValid() {
-				return deepGet(mapValue.Interface(), strings.Join(parts[1:], "."))
-			}
-		default:
-			fmt.Printf("can't group by %s\n", path)
-		}
-		return nil
-	}
-
-	return itemValue.Interface()
+func (r *RuntimeContainer) Equals(o RuntimeContainer) bool {
+	return r.ID == o.ID && r.Image == o.Image
 }
 
 func groupBy(entries []*RuntimeContainer, key string) map[string][]*RuntimeContainer {

reflect.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+func stripPrefix(s, prefix string) string {
+	path := s
+	for {
+		if strings.HasPrefix(path, ".") {
+			path = path[1:]
+			continue
+		}
+		break
+	}
+	return path
+}
+
+func deepGet(item interface{}, path string) interface{} {
+	if path == "" {
+		return item
+	}
+
+	path = stripPrefix(path, ".")
+	parts := strings.Split(path, ".")
+	itemValue := reflect.ValueOf(item)
+
+	if len(parts) > 0 {
+		switch itemValue.Kind() {
+		case reflect.Struct:
+			fieldValue := itemValue.FieldByName(parts[0])
+			if fieldValue.IsValid() {
+				return deepGet(fieldValue.Interface(), strings.Join(parts[1:], "."))
+			}
+		case reflect.Map:
+			mapValue := itemValue.MapIndex(reflect.ValueOf(parts[0]))
+			if mapValue.IsValid() {
+				return deepGet(mapValue.Interface(), strings.Join(parts[1:], "."))
+			}
+		default:
+			fmt.Printf("can't group by %s\n", path)
+		}
+		return nil
+	}
+
+	return itemValue.Interface()
+}

reflect_test.go

@@ -0,0 +1,61 @@
+package main
+
+import "testing"
+
+func TestDeepGetNoPath(t *testing.T) {
+	item := RuntimeContainer{}
+	value := deepGet(item, "")
+	if _, ok := value.(RuntimeContainer); !ok {
+		t.Fail()
+	}
+
+	var returned RuntimeContainer
+	returned = value.(RuntimeContainer)
+	if !returned.Equals(item) {
+		t.Fail()
+	}
+}
+
+func TestDeepGetSimple(t *testing.T) {
+	item := RuntimeContainer{
+		ID: "expected",
+	}
+	value := deepGet(item, "ID")
+	if _, ok := value.(string); !ok {
+		t.Errorf("expected: %u. got: %u", "expected", value)
+	}
+
+	if value != "expected" {
+		t.Errorf("expected: %s. got: %s", "expected", value)
+	}
+}
+
+func TestDeepGetSimpleDotPrefix(t *testing.T) {
+	item := RuntimeContainer{
+		ID: "expected",
+	}
+	value := deepGet(item, "...ID")
+	if _, ok := value.(string); !ok {
+		t.Errorf("expected: %u. got: %u", "expected", value)
+	}
+
+	if value != "expected" {
+		t.Errorf("expected: %s. got: %s", "expected", value)
+	}
+}
+
+func TestDeepGetMap(t *testing.T) {
+	item := RuntimeContainer{
+		Env: map[string]string{
+			"key": "value",
+		},
+	}
+	value := deepGet(item, "Env.key")
+	if _, ok := value.(string); !ok {
+		t.Errorf("expected: %u. got: %u", "value", value)
+	}
+
+	if value != "value" {
+		t.Errorf("expected: %s. got: %s", "value", value)
+	}
+}