PoC for goccy#4

decode.go

@@ -10,7 +10,7 @@ import (
 	"reflect"
 
 	"github.com/goccy/go-yaml/ast"
-	"github.com/goccy/go-yaml/errors"
+	"github.com/goccy/go-yaml/internal/errors"
 	"github.com/goccy/go-yaml/lexer"
 	"github.com/goccy/go-yaml/parser"
 	"github.com/goccy/go-yaml/token"

decode_test.go

@@ -343,3 +343,25 @@ items:
 		t.Fatal("failed to decode with merge key")
 	}
 }
+
+func TestDecoder_InvalidCases(t *testing.T) {
+	const src = `---
+a:
+- b
+  c: d
+`
+	var v struct {
+		A []string
+	}
+	err := yaml.NewDecoder(strings.NewReader(src)).Decode(&v)
+	if err == nil {
+		t.Fatalf("expected error")
+	}
+
+	//TODO: properly check if errors are colored/have source
+	t.Logf("%s", err)
+	t.Logf("%s", yaml.FormatError(err, true, false))
+	t.Logf("%s", yaml.FormatError(err, false, true))
+	t.Logf("%s", yaml.FormatError(err, true, true))
+}
+

encode.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 
 	"github.com/goccy/go-yaml/ast"
-	"github.com/goccy/go-yaml/errors"
+	"github.com/goccy/go-yaml/internal/errors"
 	"github.com/goccy/go-yaml/printer"
 	"github.com/goccy/go-yaml/token"
 	"golang.org/x/xerrors"

errors/error.go → internal/errors/error.go

@@ -1,6 +1,7 @@
 package errors
 
 import (
+	"bytes"
 	"fmt"
 
 	"github.com/goccy/go-yaml/printer"
@@ -66,6 +67,16 @@ type wrapError struct {
 	frame   xerrors.Frame
 }
 
+type myprinter struct {
+	xerrors.Printer
+	colored    bool
+	inclSource bool
+}
+
+func (e *wrapError) PrettyPrint(p xerrors.Printer, colored, inclSource bool) error {
+	return e.FormatError(&myprinter{Printer: p, colored: colored, inclSource: inclSource})
+}
+
 func (e *wrapError) FormatError(p xerrors.Printer) error {
 	if e.verb == 'v' && e.state.Flag('+') {
 		// print stack trace for debugging
@@ -134,25 +145,53 @@ type syntaxError struct {
 	frame xerrors.Frame
 }
 
+func (e *syntaxError) PrettyPrint(p xerrors.Printer, colored, inclSource bool) error {
+	return e.FormatError(&myprinter{Printer: p, colored: colored, inclSource: inclSource})
+}
+
 func (e *syntaxError) FormatError(p xerrors.Printer) error {
+	var pp printer.Printer
+
+	var colored, inclSource bool
+	if mp,ok := p.(*myprinter); ok {
+		colored = mp.colored
+		inclSource = mp.inclSource
+	}
+
+	pos := fmt.Sprintf("[%d:%d] ", e.token.Position.Line, e.token.Position.Column)
+	msg := pp.PrintErrorMessage(fmt.Sprintf("%s%s", pos, e.msg), colored)
+	if inclSource {
+		msg += "\n" + pp.PrintErrorToken(e.token, colored)
+	}
+	p.Print(msg)
+
 	if e.verb == 'v' && e.state.Flag('+') {
 		// %+v
 		// print stack trace for debugging
-		p.Print(e.Error())
 		e.frame.Format(p)
-	} else {
-		p.Print(e.Error())
 	}
 	return nil
 }
 
+type PrettyPrinter interface {
+	PrettyPrint(xerrors.Printer, bool, bool) error
+}
+type Sink struct{ *bytes.Buffer }
+
+func (es *Sink) Print(args ...interface{}) {
+	fmt.Fprint(es.Buffer, args...)
+}
+
+func (es *Sink) Printf(f string, args ...interface{}) {
+	fmt.Fprintf(es.Buffer, f, args...)
+}
+
+func (es *Sink) Detail() bool {
+	return false
+}
+
 func (e *syntaxError) Error() string {
-	var p printer.Printer
-	pos := fmt.Sprintf("[%d:%d] ", e.token.Position.Line, e.token.Position.Column)
-	msg := p.PrintErrorMessage(fmt.Sprintf("syntax error: %s%s", pos, e.msg), ColoredErr)
-	if WithSourceCode {
-		err := p.PrintErrorToken(e.token, ColoredErr)
-		return fmt.Sprintf("%s\n%s", msg, err)
-	}
-	return msg
+	var buf bytes.Buffer
+	e.PrettyPrint(&Sink{&buf}, false, false)
+	return buf.String()
 }

parser/parser.go

@@ -4,7 +4,7 @@ import (
 	"strings"
 
 	"github.com/goccy/go-yaml/ast"
-	"github.com/goccy/go-yaml/errors"
+	"github.com/goccy/go-yaml/internal/errors"
 	"github.com/goccy/go-yaml/token"
 )
 

yaml.go

@@ -3,7 +3,8 @@ package yaml
 import (
 	"bytes"
 
-	"github.com/goccy/go-yaml/errors"
+	"github.com/goccy/go-yaml/internal/errors"
+	"golang.org/x/xerrors"
 )
 
 // Marshaler interface may be implemented by types to customize their
@@ -111,3 +112,15 @@ func Unmarshal(data []byte, v interface{}) error {
 	}
 	return nil
 }
+
+func FormatError(e error, colored, inclSource bool) string {
+	var pp errors.PrettyPrinter
+	if xerrors.As(e, &pp) {
+		var buf bytes.Buffer
+		pp.PrettyPrint(&errors.Sink{&buf}, colored, inclSource)
+		return buf.String()
+	}
+
+	return e.Error()
+
+}