Merge 4529e3b into b9b2581

builder.go

@@ -5,7 +5,7 @@ import (
 )
 
 type builder interface {
-	build(fields []string) (formatter, error)
+	build(fields []string, prefix string) (formatter, error)
 }
 
 func makeBuilder(t reflect.Type) (builder, error) {

format.go

@@ -49,7 +49,7 @@ func (f *Formatter) Format(o interface{}, fields []string) (interface{}, error)
 	ff := f.formatters[t][key]
 	if ff == nil {
 		var err error
-		ff, err = b.build(fields)
+		ff, err = b.build(fields, "")
 		if err != nil {
 			return nil, err
 		}

format_test.go

@@ -17,10 +17,33 @@ func TestFormat(t *testing.T) {
 		err    string
 	}{
 		{
-			src:    struct{ Foo int }{Foo: 1},
+			src:    struct{ Foo int }{},
 			format: "bar",
 			err:    "field 'bar' does not exist",
 		},
+		{
+			src: struct {
+				foo int
+			}{},
+			format: "foo",
+			err:    "field 'foo' does not exist",
+		},
+		{
+			src: struct {
+				Foo int `json:"foo"`
+			}{},
+			format: "foo.bar",
+			err:    "field 'foo.bar' does not exist",
+		},
+		{
+			src: struct {
+				Foo struct {
+					Bar int `json:"bar"`
+				} `json:"foo"`
+			}{},
+			format: "foo.baz",
+			err:    "field 'foo.baz' does not exist",
+		},
 		{
 			src:    struct{ Foo int }{Foo: 1},
 			format: "",
@@ -68,6 +91,15 @@ func TestFormat(t *testing.T) {
 			format: "foo",
 			output: `{"foo":1}`,
 		},
+		{
+			src: struct {
+				Foo int    `json:"foo"`
+				Bar string `json:"bar"`
+				Baz int    `json:"-"`
+			}{Foo: 1, Bar: "bar", Baz: 2},
+			format: "foo",
+			output: `{"foo":1}`,
+		},
 		{
 			src: struct {
 				Foo int    `json:"foo"`
@@ -345,7 +377,7 @@ func TestFormat(t *testing.T) {
 			o, err := f.Format(tt.src, fields)
 			if tt.err != "" {
 				if err == nil {
-					t.Fail()
+					t.FailNow()
 				}
 				if tt.err != err.Error() {
 					t.Errorf("Returned error '%v', expected '%s'", err, tt.err)

pointer.go

@@ -28,8 +28,8 @@ type pointerBuilder struct {
 	elem *structBuilder
 }
 
-func (b *pointerBuilder) build(fields []string) (formatter, error) {
-	ef, err := b.elem.build(fields)
+func (b *pointerBuilder) build(fields []string, prefix string) (formatter, error) {
+	ef, err := b.elem.build(fields, prefix)
 	if err != nil {
 		return nil, err
 	}

primitive.go

@@ -1,6 +1,9 @@
 package dynjson
 
-import "reflect"
+import (
+	"fmt"
+	"reflect"
+)
 
 type primitiveFormatter struct {
 	t reflect.Type
@@ -18,7 +21,10 @@ type primitiveBuilder struct {
 	t reflect.Type
 }
 
-func (b *primitiveBuilder) build(fields []string) (formatter, error) {
+func (b *primitiveBuilder) build(fields []string, prefix string) (formatter, error) {
+	if len(fields) > 0 {
+		return nil, fmt.Errorf("field '%s' does not exist", prefix+fields[0])
+	}
 	return &primitiveFormatter{t: b.t}, nil
 }
 

slice.go

@@ -28,8 +28,8 @@ type sliceBuilder struct {
 	elem *structBuilder
 }
 
-func (b *sliceBuilder) build(fields []string) (formatter, error) {
-	et, err := b.elem.build(fields)
+func (b *sliceBuilder) build(fields []string, prefix string) (formatter, error) {
+	et, err := b.elem.build(fields, prefix)
 	if err != nil {
 		return nil, err
 	}

struct.go

@@ -42,7 +42,7 @@ type structBuilder struct {
 	fields   map[string]reflect.StructField
 }
 
-func (b *structBuilder) build(fields []string) (formatter, error) {
+func (b *structBuilder) build(fields []string, prefix string) (formatter, error) {
 	if len(fields) == 0 {
 		return &primitiveFormatter{t: b.t}, nil
 	}
@@ -66,9 +66,9 @@ func (b *structBuilder) build(fields []string) (formatter, error) {
 		}
 		subb := b.builders[field]
 		if subb == nil {
-			return nil, fmt.Errorf("field '%s' does not exist", field)
+			return nil, fmt.Errorf("field '%s' does not exist", prefix+field)
 		}
-		fmter, err := subb.build(subfields)
+		fmter, err := subb.build(subfields, prefix+field+".")
 		if err != nil {
 			return nil, err
 		}
@@ -90,9 +90,6 @@ func (b *structBuilder) build(fields []string) (formatter, error) {
 }
 
 func makeStructBuilder(t reflect.Type) (*structBuilder, error) {
-	if t.Kind() != reflect.Struct {
-		return nil, fmt.Errorf("%s is not a struct", t.Name())
-	}
 	sb := structBuilder{
 		t:        t,
 		builders: map[string]builder{},