Allow build without json and xml support (#1556)

* Refactor ordered_map into separate files

Separate json and xml, from the regular yaml.

Makes it possible to compile, without those...

* Refactor encoder and decoder creation

Use more consistent parameters vs globals

Return errors instead of calling panic()

* Allow build without json and xml support

Author: afbjorklund

cmd/evaluate_all_command.go

@@ -84,7 +84,10 @@ func evaluateAll(cmd *cobra.Command, args []string) (cmdError error) {
 	if err != nil {
 		return err
 	}
-	encoder := configureEncoder(format)
+	encoder, err := configureEncoder()
+	if err != nil {
+		return err
+	}
 
 	printer := yqlib.NewPrinter(encoder, printerWriter)
 

cmd/evalute_sequence_command.go

@@ -93,7 +93,10 @@ func evaluateSequence(cmd *cobra.Command, args []string) (cmdError error) {
 	if err != nil {
 		return err
 	}
-	encoder := configureEncoder(format)
+	encoder, err := configureEncoder()
+	if err != nil {
+		return err
+	}
 
 	printer := yqlib.NewPrinter(encoder, printerWriter)
 

cmd/utils.go

@@ -61,7 +61,15 @@ func configureDecoder(evaluateTogether bool) (yqlib.Decoder, error) {
 	if err != nil {
 		return nil, err
 	}
-	switch yqlibInputFormat {
+	yqlibDecoder, err := createDecoder(yqlibInputFormat, evaluateTogether)
+	if yqlibDecoder == nil {
+		return nil, fmt.Errorf("no support for %s input format", inputFormat)
+	}
+	return yqlibDecoder, err
+}
+
+func createDecoder(format yqlib.InputFormat, evaluateTogether bool) (yqlib.Decoder, error) {
+	switch format {
 	case yqlib.XMLInputFormat:
 		return yqlib.NewXMLDecoder(yqlib.ConfiguredXMLPreferences), nil
 	case yqlib.PropertiesInputFormat:
@@ -72,10 +80,12 @@ func configureDecoder(evaluateTogether bool) (yqlib.Decoder, error) {
 		return yqlib.NewCSVObjectDecoder(','), nil
 	case yqlib.TSVObjectInputFormat:
 		return yqlib.NewCSVObjectDecoder('\t'), nil
+	case yqlib.YamlInputFormat:
+		prefs := yqlib.ConfiguredYamlPreferences
+		prefs.EvaluateTogether = evaluateTogether
+		return yqlib.NewYamlDecoder(prefs), nil
 	}
-	prefs := yqlib.ConfiguredYamlPreferences
-	prefs.EvaluateTogether = evaluateTogether
-	return yqlib.NewYamlDecoder(prefs), nil
+	return nil, fmt.Errorf("invalid decoder: %v", format)
 }
 
 func configurePrinterWriter(format yqlib.PrinterOutputFormat, out io.Writer) (yqlib.PrinterWriter, error) {
@@ -95,22 +105,34 @@ func configurePrinterWriter(format yqlib.PrinterOutputFormat, out io.Writer) (yq
 	return printerWriter, nil
 }
 
-func configureEncoder(format yqlib.PrinterOutputFormat) yqlib.Encoder {
+func configureEncoder() (yqlib.Encoder, error) {
+	yqlibOutputFormat, err := yqlib.OutputFormatFromString(outputFormat)
+	if err != nil {
+		return nil, err
+	}
+	yqlibEncoder, err := createEncoder(yqlibOutputFormat)
+	if yqlibEncoder == nil {
+		return nil, fmt.Errorf("no support for %s output format", outputFormat)
+	}
+	return yqlibEncoder, err
+}
+
+func createEncoder(format yqlib.PrinterOutputFormat) (yqlib.Encoder, error) {
 	switch format {
 	case yqlib.JSONOutputFormat:
-		return yqlib.NewJSONEncoder(indent, colorsEnabled, unwrapScalar)
+		return yqlib.NewJSONEncoder(indent, colorsEnabled, unwrapScalar), nil
 	case yqlib.PropsOutputFormat:
-		return yqlib.NewPropertiesEncoder(unwrapScalar)
+		return yqlib.NewPropertiesEncoder(unwrapScalar), nil
 	case yqlib.CSVOutputFormat:
-		return yqlib.NewCsvEncoder(',')
+		return yqlib.NewCsvEncoder(','), nil
 	case yqlib.TSVOutputFormat:
-		return yqlib.NewCsvEncoder('\t')
+		return yqlib.NewCsvEncoder('\t'), nil
 	case yqlib.YamlOutputFormat:
-		return yqlib.NewYamlEncoder(indent, colorsEnabled, yqlib.ConfiguredYamlPreferences)
+		return yqlib.NewYamlEncoder(indent, colorsEnabled, yqlib.ConfiguredYamlPreferences), nil
 	case yqlib.XMLOutputFormat:
-		return yqlib.NewXMLEncoder(indent, yqlib.ConfiguredXMLPreferences)
+		return yqlib.NewXMLEncoder(indent, yqlib.ConfiguredXMLPreferences), nil
 	}
-	panic("invalid encoder")
+	return nil, fmt.Errorf("invalid encoder: %v", format)
 }
 
 // this is a hack to enable backwards compatibility with githubactions (which pipe /dev/null into everything)

pkg/yqlib/decoder_json.go

@@ -1,3 +1,5 @@
+//go:build !yq_nojson
+
 package yqlib
 
 import (

pkg/yqlib/decoder_xml.go

@@ -1,3 +1,5 @@
+//go:build !yq_noxml
+
 package yqlib
 
 import (

pkg/yqlib/encoder.go

@@ -1,10 +1,6 @@
 package yqlib
 
 import (
-	"bytes"
-	"encoding/json"
-	"errors"
-	"fmt"
 	"io"
 
 	yaml "gopkg.in/yaml.v3"
@@ -17,162 +13,17 @@ type Encoder interface {
 	CanHandleAliases() bool
 }
 
-// orderedMap allows to marshal and unmarshal JSON and YAML values keeping the
-// order of keys and values in a map or an object.
-type orderedMap struct {
-	// if this is an object, kv != nil. If this is not an object, kv == nil.
-	kv     []orderedMapKV
-	altVal interface{}
-}
-
-type orderedMapKV struct {
-	K string
-	V orderedMap
-}
-
-func (o *orderedMap) UnmarshalJSON(data []byte) error {
-	switch data[0] {
-	case '{':
-		// initialise so that even if the object is empty it is not nil
-		o.kv = []orderedMapKV{}
-
-		// create decoder
-		dec := json.NewDecoder(bytes.NewReader(data))
-		_, err := dec.Token() // open object
-		if err != nil {
-			return err
-		}
-
-		// cycle through k/v
-		var tok json.Token
-		for tok, err = dec.Token(); err == nil; tok, err = dec.Token() {
-			// we can expect two types: string or Delim. Delim automatically means
-			// that it is the closing bracket of the object, whereas string means
-			// that there is another key.
-			if _, ok := tok.(json.Delim); ok {
-				break
-			}
-			kv := orderedMapKV{
-				K: tok.(string),
-			}
-			if err := dec.Decode(&kv.V); err != nil {
-				return err
-			}
-			o.kv = append(o.kv, kv)
-		}
-		// unexpected error
-		if err != nil && !errors.Is(err, io.EOF) {
-			return err
-		}
-		return nil
-	case '[':
-		var res []*orderedMap
-		if err := json.Unmarshal(data, &res); err != nil {
-			return err
-		}
-		o.altVal = res
-		o.kv = nil
-		return nil
-	}
-
-	return json.Unmarshal(data, &o.altVal)
-}
+func mapKeysToStrings(node *yaml.Node) {
 
-func (o orderedMap) MarshalJSON() ([]byte, error) {
-	buf := new(bytes.Buffer)
-	enc := json.NewEncoder(buf)
-	enc.SetEscapeHTML(false) // do not escape html chars e.g. &, <, >
-	if o.kv == nil {
-		if err := enc.Encode(o.altVal); err != nil {
-			return nil, err
-		}
-		return buf.Bytes(), nil
-	}
-	buf.WriteByte('{')
-	for idx, el := range o.kv {
-		if err := enc.Encode(el.K); err != nil {
-			return nil, err
-		}
-		buf.WriteByte(':')
-		if err := enc.Encode(el.V); err != nil {
-			return nil, err
-		}
-		if idx != len(o.kv)-1 {
-			buf.WriteByte(',')
-		}
-	}
-	buf.WriteByte('}')
-	return buf.Bytes(), nil
-}
-
-func (o *orderedMap) UnmarshalYAML(node *yaml.Node) error {
-	switch node.Kind {
-	case yaml.DocumentNode:
-		if len(node.Content) == 0 {
-			return nil
-		}
-		return o.UnmarshalYAML(node.Content[0])
-	case yaml.AliasNode:
-		return o.UnmarshalYAML(node.Alias)
-	case yaml.ScalarNode:
-		return node.Decode(&o.altVal)
-	case yaml.MappingNode:
-		// set kv to non-nil
-		o.kv = []orderedMapKV{}
-		for i := 0; i < len(node.Content); i += 2 {
-			var key string
-			var val orderedMap
-			if err := node.Content[i].Decode(&key); err != nil {
-				return err
+	if node.Kind == yaml.MappingNode {
+		for index, child := range node.Content {
+			if index%2 == 0 { // its a map key
+				child.Tag = "!!str"
 			}
-			if err := node.Content[i+1].Decode(&val); err != nil {
-				return err
-			}
-			o.kv = append(o.kv, orderedMapKV{
-				K: key,
-				V: val,
-			})
-		}
-		return nil
-	case yaml.SequenceNode:
-		// note that this has to be a pointer, so that nulls can be represented.
-		var res []*orderedMap
-		if err := node.Decode(&res); err != nil {
-			return err
 		}
-		o.altVal = res
-		o.kv = nil
-		return nil
-	case 0:
-		// null
-		o.kv = nil
-		o.altVal = nil
-		return nil
-	default:
-		return fmt.Errorf("orderedMap: invalid yaml node")
 	}
-}
 
-func (o *orderedMap) MarshalYAML() (interface{}, error) {
-	// fast path: kv is nil, use altVal
-	if o.kv == nil {
-		return o.altVal, nil
-	}
-	content := make([]*yaml.Node, 0, len(o.kv)*2)
-	for _, val := range o.kv {
-		n := new(yaml.Node)
-		if err := n.Encode(val.V); err != nil {
-			return nil, err
-		}
-		content = append(content, &yaml.Node{
-			Kind:  yaml.ScalarNode,
-			Tag:   "!!str",
-			Value: val.K,
-		}, n)
+	for _, child := range node.Content {
+		mapKeysToStrings(child)
 	}
-	return &yaml.Node{
-		Kind:    yaml.MappingNode,
-		Tag:     "!!map",
-		Content: content,
-	}, nil
 }

pkg/yqlib/encoder_json.go

@@ -1,3 +1,5 @@
+//go:build !yq_nojson
+
 package yqlib
 
 import (
@@ -14,21 +16,6 @@ type jsonEncoder struct {
 	UnwrapScalar bool
 }
 
-func mapKeysToStrings(node *yaml.Node) {
-
-	if node.Kind == yaml.MappingNode {
-		for index, child := range node.Content {
-			if index%2 == 0 { // its a map key
-				child.Tag = "!!str"
-			}
-		}
-	}
-
-	for _, child := range node.Content {
-		mapKeysToStrings(child)
-	}
-}
-
 func NewJSONEncoder(indent int, colorise bool, unwrapScalar bool) Encoder {
 	var indentString = ""
 

pkg/yqlib/encoder_test.go

@@ -1,3 +1,5 @@
+//go:build !yq_nojson
+
 package yqlib
 
 import (

pkg/yqlib/encoder_xml.go

@@ -1,3 +1,5 @@
+//go:build !yq_noxml
+
 package yqlib
 
 import (

pkg/yqlib/json_test.go

@@ -1,3 +1,5 @@
+//go:build !yq_nojson
+
 package yqlib
 
 import (