Add support for serializing squashed embedded structs

Handles embedded structs that are annotated with `mapstructure:",squash"`
creativeprojects · Dec 22, 2020 · cdc41e4 · cdc41e4
1 parent 4be5547
commit cdc41e4
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Showing 2 changed files with 151 additions and 132 deletions.
diff --git a/config/show.go b/config/show.go
@@ -1,132 +1,138 @@
-package config
-
-import (
-	"bufio"
-	"fmt"
-	"io"
-	"reflect"
-	"text/tabwriter"
-)
-
-const (
-	templateIndent = "    " // 4 spaces
-)
-
-// ShowStruct write out to w a human readable text representation of the orig parameter
-func ShowStruct(w io.Writer, orig interface{}) error {
-	return showSubStruct(w, orig, "")
-}
-
-func showSubStruct(outputWriter io.Writer, orig interface{}, prefix string) error {
-	typeOf := reflect.TypeOf(orig)
-	valueOf := reflect.ValueOf(orig)
-
-	if typeOf.Kind() == reflect.Ptr {
-		// Deference the pointer
-		typeOf = typeOf.Elem()
-		valueOf = valueOf.Elem()
-	}
-
-	// NumField() will panic if typeOf is not a struct
-	if typeOf.Kind() != reflect.Struct {
-		return fmt.Errorf("unsupported type %s, expected %s", typeOf.Kind(), reflect.Struct)
-	}
-
-	// make a temporary buffer to display sub struct and map after direct properties (which are buffered through a tabWriter)
-	buffer := bufio.NewWriter(outputWriter)
-	tabWriter := tabwriter.NewWriter(outputWriter, 0, 2, 2, ' ', 0)
-	prefix = addIndentation(prefix)
-
-	for i := 0; i < typeOf.NumField(); i++ {
-		field := typeOf.Field(i)
-
-		if key, ok := field.Tag.Lookup("mapstructure"); ok {
-			if key == "" {
-				continue
-			}
-			if valueOf.Field(i).Kind() == reflect.Ptr {
-				if valueOf.Field(i).IsNil() {
-					continue
-				}
-				// start of a new pointer to a struct
-				fmt.Fprintf(buffer, "%s%s:\n", prefix, key)
-				err := showSubStruct(buffer, valueOf.Field(i).Elem().Interface(), prefix)
-				if err != nil {
-					return err
-				}
-				continue
-			}
-			if valueOf.Field(i).Kind() == reflect.Struct {
-				// start of a new struct
-				fmt.Fprintf(buffer, "%s%s:\n", prefix, key)
-				err := showSubStruct(buffer, valueOf.Field(i).Interface(), prefix)
-				if err != nil {
-					return err
-				}
-				continue
-			}
-			if valueOf.Field(i).Kind() == reflect.Map {
-				if valueOf.Field(i).Len() == 0 {
-					continue
-				}
-				// special case of the map of remaining parameters...
-				if key == ",remain" {
-					showMap(tabWriter, prefix, valueOf.Field(i))
-					continue
-				}
-				fmt.Fprintf(buffer, "%s%s:\n", prefix, key)
-				showNewMap(buffer, prefix, valueOf.Field(i))
-				continue
-			}
-			showKeyValue(tabWriter, prefix, key, valueOf.Field(i))
-		}
-	}
-
-	tabWriter.Flush()
-	fmt.Fprintln(buffer, "")
-	buffer.Flush()
-
-	return nil
-}
-
-func addIndentation(indent string) string {
-	return indent + templateIndent
-}
-
-func showNewMap(outputWriter io.Writer, prefix string, valueOf reflect.Value) {
-	subWriter := tabwriter.NewWriter(outputWriter, 0, 2, 2, ' ', 0)
-	prefix = addIndentation(prefix)
-	showMap(subWriter, prefix, valueOf)
-	subWriter.Flush()
-	fmt.Fprintln(outputWriter, "")
-}
-
-func showMap(tabWriter io.Writer, prefix string, valueOf reflect.Value) {
-	iter := valueOf.MapRange()
-	for iter.Next() {
-		showKeyValue(tabWriter, prefix, iter.Key().String(), iter.Value())
-	}
-}
-
-func showKeyValue(tabWriter io.Writer, prefix, key string, valueOf reflect.Value) {
-	// hard-coded case for "inherit": we don't need to display it
-	if key == "inherit" {
-		return
-	}
-	// This is reusing the stringifyValue function used to build the restic flags
-	convert, ok := stringifyValue(valueOf)
-	if ok {
-		if len(convert) == 0 {
-			// special case of a true flag that shows no value
-			convert = append(convert, "true")
-		}
-		if len(convert) > 0 {
-			fmt.Fprintf(tabWriter, "%s%s:\t%s\n", prefix, key, convert[0])
-		}
-		if len(convert) > 1 {
-			for i := 1; i < len(convert); i++ {
-				fmt.Fprintf(tabWriter, "%s\t%s\n", prefix, convert[i])
-			}
-		}
-	}
-}
+package config
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"reflect"
+	"text/tabwriter"
+)
+
+const (
+	templateIndent = "    " // 4 spaces
+)
+
+// ShowStruct write out to w a human readable text representation of the orig parameter
+func ShowStruct(w io.Writer, orig interface{}) error {
+	return showSubStruct(w, orig, "")
+}
+
+func showSubStruct(outputWriter io.Writer, orig interface{}, prefix string) error {
+	typeOf := reflect.TypeOf(orig)
+	valueOf := reflect.ValueOf(orig)
+
+	if typeOf.Kind() == reflect.Ptr {
+		// Deference the pointer
+		typeOf = typeOf.Elem()
+		valueOf = valueOf.Elem()
+	}
+
+	// NumField() will panic if typeOf is not a struct
+	if typeOf.Kind() != reflect.Struct {
+		return fmt.Errorf("unsupported type %s, expected %s", typeOf.Kind(), reflect.Struct)
+	}
+
+	// make a temporary buffer to display sub struct and map after direct properties (which are buffered through a tabWriter)
+	buffer := bufio.NewWriter(outputWriter)
+	tabWriter := tabwriter.NewWriter(outputWriter, 0, 2, 2, ' ', 0)
+	prefix = addIndentation(prefix)
+
+	for i := 0; i < typeOf.NumField(); i++ {
+		field := typeOf.Field(i)
+
+		if key, ok := field.Tag.Lookup("mapstructure"); ok {
+			if key == "" {
+				continue
+			}
+			if valueOf.Field(i).Kind() == reflect.Ptr {
+				if valueOf.Field(i).IsNil() {
+					continue
+				}
+				// start of a new pointer to a struct
+				fmt.Fprintf(buffer, "%s%s:\n", prefix, key)
+				err := showSubStruct(buffer, valueOf.Field(i).Elem().Interface(), prefix)
+				if err != nil {
+					return err
+				}
+				continue
+			}
+			if valueOf.Field(i).Kind() == reflect.Struct {
+				var err error
+				if key == ",squash" {
+					p := prefix[0 : len(prefix)-len(templateIndent)]
+					err = showSubStruct(tabWriter, valueOf.Field(i).Interface(), p)
+				} else {
+					// start of a new struct
+					fmt.Fprintf(buffer, "%s%s:\n", prefix, key)
+					err = showSubStruct(buffer, valueOf.Field(i).Interface(), prefix)
+				}
+				if err != nil {
+					return err
+				}
+				continue
+			}
+			if valueOf.Field(i).Kind() == reflect.Map {
+				if valueOf.Field(i).Len() == 0 {
+					continue
+				}
+				// special case of the map of remaining parameters...
+				if key == ",remain" {
+					showMap(tabWriter, prefix, valueOf.Field(i))
+					continue
+				}
+				fmt.Fprintf(buffer, "%s%s:\n", prefix, key)
+				showNewMap(buffer, prefix, valueOf.Field(i))
+				continue
+			}
+			showKeyValue(tabWriter, prefix, key, valueOf.Field(i))
+		}
+	}
+
+	tabWriter.Flush()
+	fmt.Fprintln(buffer, "")
+	buffer.Flush()
+
+	return nil
+}
+
+func addIndentation(indent string) string {
+	return indent + templateIndent
+}
+
+func showNewMap(outputWriter io.Writer, prefix string, valueOf reflect.Value) {
+	subWriter := tabwriter.NewWriter(outputWriter, 0, 2, 2, ' ', 0)
+	prefix = addIndentation(prefix)
+	showMap(subWriter, prefix, valueOf)
+	subWriter.Flush()
+	fmt.Fprintln(outputWriter, "")
+}
+
+func showMap(tabWriter io.Writer, prefix string, valueOf reflect.Value) {
+	iter := valueOf.MapRange()
+	for iter.Next() {
+		showKeyValue(tabWriter, prefix, iter.Key().String(), iter.Value())
+	}
+}
+
+func showKeyValue(tabWriter io.Writer, prefix, key string, valueOf reflect.Value) {
+	// hard-coded case for "inherit": we don't need to display it
+	if key == "inherit" {
+		return
+	}
+	// This is reusing the stringifyValue function used to build the restic flags
+	convert, ok := stringifyValue(valueOf)
+	if ok {
+		if len(convert) == 0 {
+			// special case of a true flag that shows no value
+			convert = append(convert, "true")
+		}
+		if len(convert) > 0 {
+			fmt.Fprintf(tabWriter, "%s%s:\t%s\n", prefix, key, convert[0])
+		}
+		if len(convert) > 1 {
+			for i := 1; i < len(convert); i++ {
+				fmt.Fprintf(tabWriter, "%s\t%s\n", prefix, convert[i])
+			}
+		}
+	}
+}
diff --git a/config/show_test.go b/config/show_test.go
@@ -30,6 +30,15 @@ type testPointer struct {
 	IsValid bool `mapstructure:"valid"`
 }
 
+type testEmbedded struct {
+	EmbeddedStruct `mapstructure:",squash"`
+	InlineValue    int `mapstructure:"inline"`
+}
+
+type EmbeddedStruct struct {
+	Value bool `mapstructure:"value"`
+}
+
 func TestShowStruct(t *testing.T) {
 	testData := []showStructData{
 		{
@@ -58,6 +67,10 @@ func TestShowStruct(t *testing.T) {
 			input:  testObject{Id: 11, Name: "test", Map: map[string][]string{"left": {"over"}}},
 			output: " person:\n\n id: 11\n name:  test\n left:  over\n\n",
 		},
+		{
+			input:  testEmbedded{EmbeddedStruct{Value: true}, 1},
+			output: " value:  true\n\n inline:  1\n\n",
+		},
 	}
 
 	for _, testItem := range testData {