Merge pull request #3 from po3rin/improve_err_msg

improve err message

Author: po3rin

README.md

@@ -44,6 +44,6 @@ Flags:
 
 ## Vim Plugin
 
-VIm plugin version is here! this plugin lets you to run automatically when saved.
+Vim plugin version is here! this plugin lets you to run automatically when saved.
 
 <a href="https://github.com/po3rin/vim-gofmtmd"><img src="https://github-link-card.s3.ap-northeast-1.amazonaws.com/po3rin/vim-gofmtmd.png" width="460px"></a>

go.mod

@@ -6,6 +6,5 @@ require (
 	github.com/sergi/go-diff v1.0.0
 	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect
 	github.com/spf13/cobra v0.0.5
-	github.com/spf13/viper v1.3.2
 	gopkg.in/russross/blackfriday.v2 v2.0.0
 )

go.sum

@@ -4,6 +4,7 @@ github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc
 github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8NzMklzPG4d5KIOhIy30Tk=
 github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
@@ -18,6 +19,7 @@ github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQz
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
 github.com/pelletier/go-toml v1.2.0 h1:T5zMGML61Wp+FlcbWjRDT7yAxhJNAiPPLOFECq181zc=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
 github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
@@ -36,6 +38,7 @@ github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/viper v1.3.2 h1:VUFqw5KcqRf7i70GOzW7N+Q7+gxVBkSSqiXB12+JQ4M=
 github.com/spf13/viper v1.3.2/go.mod h1:ZiWeW+zYFKm7srdB9IoDzzZXaJaI5eL9QjNiN/DMA2s=
+github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=

gofmtmd.go

@@ -4,6 +4,8 @@ import (
 	"bytes"
 	"fmt"
 	"go/format"
+	"strconv"
+	"strings"
 
 	"gopkg.in/russross/blackfriday.v2"
 )
@@ -15,7 +17,7 @@ func FmtGoCodeInMarkdown(md []byte) ([]byte, error) {
 	n := blackfriday.New(blackfriday.WithExtensions(blackfriday.FencedCode)).Parse(md)
 	n.Walk(genFmtWalker(&md, &err))
 	if err != nil {
-		return nil, fmt.Errorf("[gofmtmd] failed to format go source code. Please check syntax : %v", err)
+		return nil, fmt.Errorf("[gofmtmd] %w", err)
 	}
 	return md, nil
 }
@@ -29,7 +31,14 @@ func genFmtWalker(md *[]byte, fmterr *error) blackfriday.NodeVisitor {
 		if isGoCodeBlock(node) {
 			fmted, err := format.Source(node.Literal)
 			if err != nil {
-				*fmterr = err
+				line := strings.Split(err.Error(), ":")[0]
+				i, cvtErr := strconv.Atoi(line)
+				if cvtErr != nil {
+					*fmterr = fmt.Errorf("failed to parse error msg: %w", cvtErr)
+				} else {
+					code := bytes.Split(node.Literal, []byte("\n"))
+					*fmterr = fmt.Errorf("line='%s', msg='%w'", string(code[i+1]), err)
+				}
 				return blackfriday.Terminate
 			}
 			*md = bytes.ReplaceAll(*md, bytes.TrimRight(node.Literal, "\n"), bytes.TrimRight(fmted, "\n"))

testdata/syntaxerror.md

@@ -0,0 +1,9 @@
+# Syntax Error
+
+this is syntax error
+
+```go
+import "dddd"
+
+funcmain(){}
+```