Adding upstream version 9.0.3.

Signed-off-by: Daniel Baumann <daniel@debian.org>

2 files changed, 739 insertions, 0 deletions

diff --git a/modules/csv/csv.go b/modules/csv/csv.go
new file mode 100644
index 0000000..35c5d6a
--- /dev/null
+++ b/modules/csv/csv.go
@@ -0,0 +1,149 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package csv
+
+import (
+	"bytes"
+	stdcsv "encoding/csv"
+	"io"
+	"path/filepath"
+	"regexp"
+	"strings"
+
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/translation"
+	"code.gitea.io/gitea/modules/util"
+)
+
+const (
+	maxLines        = 10
+	guessSampleSize = 1e4 // 10k
+)
+
+// CreateReader creates a csv.Reader with the given delimiter.
+func CreateReader(input io.Reader, delimiter rune) *stdcsv.Reader {
+	rd := stdcsv.NewReader(input)
+	rd.Comma = delimiter
+	if delimiter != '\t' && delimiter != ' ' {
+		// TrimLeadingSpace can't be true when delimiter is a tab or a space as the value for a column might be empty,
+		// thus would change `\t\t` to just `\t` or `  ` (two spaces) to just ` ` (single space)
+		rd.TrimLeadingSpace = true
+	}
+	return rd
+}
+
+// CreateReaderAndDetermineDelimiter tries to guess the field delimiter from the content and creates a csv.Reader.
+// Reads at most guessSampleSize bytes.
+func CreateReaderAndDetermineDelimiter(ctx *markup.RenderContext, rd io.Reader) (*stdcsv.Reader, error) {
+	data := make([]byte, guessSampleSize)
+	size, err := util.ReadAtMost(rd, data)
+	if err != nil {
+		return nil, err
+	}
+
+	return CreateReader(
+		io.MultiReader(bytes.NewReader(data[:size]), rd),
+		determineDelimiter(ctx, data[:size]),
+	), nil
+}
+
+// determineDelimiter takes a RenderContext and if it isn't nil and the Filename has an extension that specifies the delimiter,
+// it is used as the delimiter. Otherwise we call guessDelimiter with the data passed
+func determineDelimiter(ctx *markup.RenderContext, data []byte) rune {
+	extension := ".csv"
+	if ctx != nil {
+		extension = strings.ToLower(filepath.Ext(ctx.RelativePath))
+	}
+
+	var delimiter rune
+	switch extension {
+	case ".tsv":
+		delimiter = '\t'
+	case ".psv":
+		delimiter = '|'
+	default:
+		delimiter = guessDelimiter(data)
+	}
+
+	return delimiter
+}
+
+// quoteRegexp follows the RFC-4180 CSV standard for when double-quotes are used to enclose fields, then a double-quote appearing inside a
+// field must be escaped by preceding it with another double quote. https://www.ietf.org/rfc/rfc4180.txt
+// This finds all quoted strings that have escaped quotes.
+var quoteRegexp = regexp.MustCompile(`"[^"]*"`)
+
+// removeQuotedStrings uses the quoteRegexp to remove all quoted strings so that we can reliably have each row on one line
+// (quoted strings often have new lines within the string)
+func removeQuotedString(text string) string {
+	return quoteRegexp.ReplaceAllLiteralString(text, "")
+}
+
+// guessDelimiter takes up to maxLines of the CSV text, iterates through the possible delimiters, and sees if the CSV Reader reads it without throwing any errors.
+// If more than one delimiter passes, the delimiter that results in the most columns is returned.
+func guessDelimiter(data []byte) rune {
+	delimiter := guessFromBeforeAfterQuotes(data)
+	if delimiter != 0 {
+		return delimiter
+	}
+
+	// Removes quoted values so we don't have columns with new lines in them
+	text := removeQuotedString(string(data))
+
+	// Make the text just be maxLines or less, ignoring truncated lines
+	lines := strings.SplitN(text, "\n", maxLines+1) // Will contain at least one line, and if there are more than MaxLines, the last item holds the rest of the lines
+	if len(lines) > maxLines {
+		// If the length of lines is > maxLines we know we have the max number of lines, trim it to maxLines
+		lines = lines[:maxLines]
+	} else if len(lines) > 1 && len(data) >= guessSampleSize {
+		// Even with data >= guessSampleSize, we don't have maxLines + 1 (no extra lines, must have really long lines)
+		// thus the last line is probably have a truncated line. Drop the last line if len(lines) > 1
+		lines = lines[:len(lines)-1]
+	}
+
+	// Put lines back together as a string
+	text = strings.Join(lines, "\n")
+
+	delimiters := []rune{',', '\t', ';', '|', '@'}
+	validDelim := delimiters[0]
+	validDelimColCount := 0
+	for _, delim := range delimiters {
+		csvReader := stdcsv.NewReader(strings.NewReader(text))
+		csvReader.Comma = delim
+		if rows, err := csvReader.ReadAll(); err == nil && len(rows) > 0 && len(rows[0]) > validDelimColCount {
+			validDelim = delim
+			validDelimColCount = len(rows[0])
+		}
+	}
+	return validDelim
+}
+
+// FormatError converts csv errors into readable messages.
+func FormatError(err error, locale translation.Locale) (string, error) {
+	if perr, ok := err.(*stdcsv.ParseError); ok {
+		if perr.Err == stdcsv.ErrFieldCount {
+			return locale.TrString("repo.error.csv.invalid_field_count", perr.Line), nil
+		}
+		return locale.TrString("repo.error.csv.unexpected", perr.Line, perr.Column), nil
+	}
+
+	return "", err
+}
+
+// Looks for possible delimiters right before or after (with spaces after the former) double quotes with closing quotes
+var beforeAfterQuotes = regexp.MustCompile(`([,@\t;|]{0,1}) *(?:"[^"]*")+([,@\t;|]{0,1})`)
+
+// guessFromBeforeAfterQuotes guesses the limiter by finding a double quote that has a valid delimiter before it and a closing quote,
+// or a double quote with a closing quote and a valid delimiter after it
+func guessFromBeforeAfterQuotes(data []byte) rune {
+	rs := beforeAfterQuotes.FindStringSubmatch(string(data)) // returns first match, or nil if none
+	if rs != nil {
+		if rs[1] != "" {
+			return rune(rs[1][0]) // delimiter found left of quoted string
+		} else if rs[2] != "" {
+			return rune(rs[2][0]) // delimiter found right of quoted string
+		}
+	}
+	return 0 // no match found
+}
diff --git a/modules/csv/csv_test.go b/modules/csv/csv_test.go
new file mode 100644
index 0000000..6ed6986
--- /dev/null
+++ b/modules/csv/csv_test.go
@@ -0,0 +1,590 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package csv
+
+import (
+	"bytes"
+	"encoding/csv"
+	"io"
+	"strconv"
+	"strings"
+	"testing"
+
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/translation"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCreateReader(t *testing.T) {
+	rd := CreateReader(bytes.NewReader([]byte{}), ',')
+	assert.Equal(t, ',', rd.Comma)
+}
+
+func decodeSlashes(t *testing.T, s string) string {
+	s = strings.ReplaceAll(s, "\n", "\\n")
+	s = strings.ReplaceAll(s, "\"", "\\\"")
+	decoded, err := strconv.Unquote(`"` + s + `"`)
+	require.NoError(t, err, "unable to decode string")
+	return decoded
+}
+
+func TestCreateReaderAndDetermineDelimiter(t *testing.T) {
+	cases := []struct {
+		csv               string
+		expectedRows      [][]string
+		expectedDelimiter rune
+	}{
+		// case 0 - semicolon delimited
+		{
+			csv: `a;b;c
+1;2;3
+4;5;6`,
+			expectedRows: [][]string{
+				{"a", "b", "c"},
+				{"1", "2", "3"},
+				{"4", "5", "6"},
+			},
+			expectedDelimiter: ';',
+		},
+		// case 1 - tab delimited with empty fields
+		{
+			csv: `col1	col2	col3
+a,	b	c
+	e	f
+g	h	i
+j		l
+m	n,\t
+p	q	r
+		u
+v	w	x
+y\t\t
+		`,
+			expectedRows: [][]string{
+				{"col1", "col2", "col3"},
+				{"a,", "b", "c"},
+				{"", "e", "f"},
+				{"g", "h", "i"},
+				{"j", "", "l"},
+				{"m", "n,", ""},
+				{"p", "q", "r"},
+				{"", "", "u"},
+				{"v", "w", "x"},
+				{"y", "", ""},
+				{"", "", ""},
+			},
+			expectedDelimiter: '\t',
+		},
+		// case 2 - comma delimited with leading spaces
+		{
+			csv: ` col1,col2,col3
+ a, b, c
+d,e,f
+ ,h, i
+j, ,\x20
+ , , `,
+			expectedRows: [][]string{
+				{"col1", "col2", "col3"},
+				{"a", "b", "c"},
+				{"d", "e", "f"},
+				{"", "h", "i"},
+				{"j", "", ""},
+				{"", "", ""},
+			},
+			expectedDelimiter: ',',
+		},
+	}
+
+	for n, c := range cases {
+		rd, err := CreateReaderAndDetermineDelimiter(nil, strings.NewReader(decodeSlashes(t, c.csv)))
+		require.NoError(t, err, "case %d: should not throw error: %v\n", n, err)
+		assert.EqualValues(t, c.expectedDelimiter, rd.Comma, "case %d: delimiter should be '%c', got '%c'", n, c.expectedDelimiter, rd.Comma)
+		rows, err := rd.ReadAll()
+		require.NoError(t, err, "case %d: should not throw error: %v\n", n, err)
+		assert.EqualValues(t, c.expectedRows, rows, "case %d: rows should be equal", n)
+	}
+}
+
+type mockReader struct{}
+
+func (r *mockReader) Read(buf []byte) (int, error) {
+	return 0, io.ErrShortBuffer
+}
+
+func TestDetermineDelimiterShortBufferError(t *testing.T) {
+	rd, err := CreateReaderAndDetermineDelimiter(nil, &mockReader{})
+	require.Error(t, err, "CreateReaderAndDetermineDelimiter() should throw an error")
+	require.ErrorIs(t, err, io.ErrShortBuffer)
+	assert.Nil(t, rd, "CSV reader should be mnil")
+}
+
+func TestDetermineDelimiterReadAllError(t *testing.T) {
+	rd, err := CreateReaderAndDetermineDelimiter(nil, strings.NewReader(`col1,col2
+	a;b
+	c@e
+	f	g
+	h|i
+	jkl`))
+	require.NoError(t, err, "CreateReaderAndDetermineDelimiter() shouldn't throw error")
+	assert.NotNil(t, rd, "CSV reader should not be mnil")
+	rows, err := rd.ReadAll()
+	require.Error(t, err, "RaadAll() should throw error")
+	require.ErrorIs(t, err, csv.ErrFieldCount)
+	assert.Empty(t, rows, "rows should be empty")
+}
+
+func TestDetermineDelimiter(t *testing.T) {
+	cases := []struct {
+		csv               string
+		filename          string
+		expectedDelimiter rune
+	}{
+		// case 0 - semicolon delmited
+		{
+			csv:               "a",
+			filename:          "test.csv",
+			expectedDelimiter: ',',
+		},
+		// case 1 - single column/row CSV
+		{
+			csv:               "a",
+			filename:          "",
+			expectedDelimiter: ',',
+		},
+		// case 2 - single column, single row CSV w/ tsv file extension (so is tabbed delimited)
+		{
+			csv:               "1,2",
+			filename:          "test.tsv",
+			expectedDelimiter: '\t',
+		},
+		// case 3 - two column, single row CSV w/ no filename, so will guess comma as delimiter
+		{
+			csv:               "1,2",
+			filename:          "",
+			expectedDelimiter: ',',
+		},
+		// case 4 - semi-colon delimited with csv extension
+		{
+			csv:               "1;2",
+			filename:          "test.csv",
+			expectedDelimiter: ';',
+		},
+		// case 5 - tabbed delimited with tsv extension
+		{
+			csv:               "1\t2",
+			filename:          "test.tsv",
+			expectedDelimiter: '\t',
+		},
+		// case 6 - tabbed delimited without any filename
+		{
+			csv:               "1\t2",
+			filename:          "",
+			expectedDelimiter: '\t',
+		},
+		// case 7 - tabs won't work, only commas as every row has same amount of commas
+		{
+			csv:               "col1,col2\nfirst\tval,seconed\tval",
+			filename:          "",
+			expectedDelimiter: ',',
+		},
+		// case 8 - While looks like comma delimited, has psv extension
+		{
+			csv:               "1,2",
+			filename:          "test.psv",
+			expectedDelimiter: '|',
+		},
+		// case 9 - pipe delmiited with no extension
+		{
+			csv:               "1|2",
+			filename:          "",
+			expectedDelimiter: '|',
+		},
+		// case 10 - semi-colon delimited with commas in values
+		{
+			csv:               "1,2,3;4,5,6;7,8,9\na;b;c",
+			filename:          "",
+			expectedDelimiter: ';',
+		},
+		// case 11 - semi-colon delimited with newline in content
+		{
+			csv: `"1,2,3,4";"a
+b";%
+c;d;#`,
+			filename:          "",
+			expectedDelimiter: ';',
+		},
+		// case 12 - HTML as single value
+		{
+			csv:               "<br/>",
+			filename:          "",
+			expectedDelimiter: ',',
+		},
+		// case 13 - tab delimited with commas in values
+		{
+			csv: `name	email	note
+John Doe	john@doe.com	This,note,had,a,lot,of,commas,to,test,delimiters`,
+			filename:          "",
+			expectedDelimiter: '\t',
+		},
+	}
+
+	for n, c := range cases {
+		delimiter := determineDelimiter(&markup.RenderContext{
+			Ctx:          git.DefaultContext,
+			RelativePath: c.filename,
+		}, []byte(decodeSlashes(t, c.csv)))
+		assert.EqualValues(t, c.expectedDelimiter, delimiter, "case %d: delimiter should be equal, expected '%c' got '%c'", n, c.expectedDelimiter, delimiter)
+	}
+}
+
+func TestRemoveQuotedString(t *testing.T) {
+	cases := []struct {
+		text         string
+		expectedText string
+	}{
+		// case 0 - quoted text with escaped quotes in 1st column
+		{
+			text: `col1,col2,col3
+"quoted ""text"" with
+new lines
+in first column",b,c`,
+			expectedText: `col1,col2,col3
+,b,c`,
+		},
+		// case 1 - quoted text with escaped quotes in 2nd column
+		{
+			text: `col1,col2,col3
+a,"quoted ""text"" with
+new lines
+in second column",c`,
+			expectedText: `col1,col2,col3
+a,,c`,
+		},
+		// case 2 - quoted text with escaped quotes in last column
+		{
+			text: `col1,col2,col3
+a,b,"quoted ""text"" with
+new lines
+in last column"`,
+			expectedText: `col1,col2,col3
+a,b,`,
+		},
+		// case 3 - csv with lots of quotes
+		{
+			text: `a,"b",c,d,"e
+e
+e",f
+a,bb,c,d,ee ,"f
+f"
+a,b,"c ""
+c",d,e,f`,
+			expectedText: `a,,c,d,,f
+a,bb,c,d,ee ,
+a,b,,d,e,f`,
+		},
+		// case 4 - csv with pipes and quotes
+		{
+			text: `Col1 | Col2 | Col3
+abc   | "Hello
+World"|123
+"de
+
+f" | 4.56 | 789`,
+			expectedText: `Col1 | Col2 | Col3
+abc   | |123
+ | 4.56 | 789`,
+		},
+	}
+
+	for n, c := range cases {
+		modifiedText := removeQuotedString(decodeSlashes(t, c.text))
+		assert.EqualValues(t, c.expectedText, modifiedText, "case %d: modified text should be equal", n)
+	}
+}
+
+func TestGuessDelimiter(t *testing.T) {
+	cases := []struct {
+		csv               string
+		expectedDelimiter rune
+	}{
+		// case 0 - single cell, comma delmited
+		{
+			csv:               "a",
+			expectedDelimiter: ',',
+		},
+		// case 1 - two cells, comma delimited
+		{
+			csv:               "1,2",
+			expectedDelimiter: ',',
+		},
+		// case 2 - semicolon delimited
+		{
+			csv:               "1;2",
+			expectedDelimiter: ';',
+		},
+		// case 3 - tab delimited
+		{
+			csv:               "1\t2",
+			expectedDelimiter: '\t',
+		},
+		// case 4 - pipe delimited
+		{
+			csv:               "1|2",
+			expectedDelimiter: '|',
+		},
+		// case 5 - semicolon delimited with commas in text
+		{
+			csv: `1,2,3;4,5,6;7,8,9
+a;b;c`,
+			expectedDelimiter: ';',
+		},
+		// case 6 - semicolon delmited with commas in quoted text
+		{
+			csv: `"1,2,3,4";"a
+b"
+c;d`,
+			expectedDelimiter: ';',
+		},
+		// case 7 - HTML
+		{
+			csv:               "<br/>",
+			expectedDelimiter: ',',
+		},
+		// case 8 - tab delimited with commas in value
+		{
+			csv: `name	email	note
+John Doe	john@doe.com	This,note,had,a,lot,of,commas,to,test,delimiters`,
+			expectedDelimiter: '\t',
+		},
+		// case 9 - tab delimited with new lines in values, commas in values
+		{
+			csv: `1	"some,""more
+""
+	quoted,
+text,"	a
+2	"some,
+quoted,\t
+	text,"	b
+3	"some,
+quoted,
+	text"	c
+4	"some,
+quoted,
+text,"	d`,
+			expectedDelimiter: '\t',
+		},
+		// case 10 - semicolon delmited with quotes and semicolon in value
+		{
+			csv: `col1;col2
+"this has a literal "" in the text";"and an ; in the text"`,
+			expectedDelimiter: ';',
+		},
+		// case 11 - pipe delimited with quotes
+		{
+			csv: `Col1 | Col2 | Col3
+abc   | "Hello
+World"|123
+"de
+|
+f" | 4.56 | 789`,
+			expectedDelimiter: '|',
+		},
+		// case 12 - a tab delimited 6 column CSV, but the values are not quoted and have lots of commas.
+		// In the previous bestScore algorithm, this would have picked comma as the delimiter, but now it should guess tab
+		{
+			csv: `c1	c2	c3	c4	c5	c6
+v,k,x,v	ym,f,oa,qn,uqijh,n,s,wvygpo	uj,kt,j,w,i,fvv,tm,f,ddt,b,mwt,e,t,teq,rd,p,a	e,wfuae,t,h,q,im,ix,y	h,mrlu,l,dz,ff,zi,af,emh	,gov,bmfelvb,axp,f,u,i,cni,x,z,v,sh,w,jo,,m,h
+k,ohf,pgr,tde,m,s	te,ek,,v,,ic,kqc,dv,w,oi,j,w,gojjr,ug,,l,j,zl	g,qziq,bcajx,zfow,ka,j,re,ohbc	k,nzm,qm,ts,auf	th,elb,lx,l,q,e,qf	asbr,z,k,y,tltobga
+g,m,bu,el	h,l,jwi,o,wge,fy,rure,c,g,lcxu,fxte,uns,cl,s,o,t,h,rsoy,f	bq,s,uov,z,ikkhgyg,,sabs,c,hzue	mc,b,,j,t,n	sp,mn,,m,t,dysi,eq,pigb,rfa,z	w,rfli,sg,,o,wjjjf,f,wxdzfk,x,t,p,zy,p,mg,r,l,h
+e,ewbkc,nugd,jj,sf,ih,i,n,jo,b,poem,kw,q,i,x,t,e,uug,k	j,xm,sch,ux,h,,fb,f,pq,,mh,,f,v,,oba,w,h,v,eiz,yzd,o,a,c,e,dhp,q	a,pbef,epc,k,rdpuw,cw	k,j,e,d	xf,dz,sviv,w,sqnzew,t,b	v,yg,f,cq,ti,g,m,ta,hm,ym,ii,hxy,p,z,r,e,ga,sfs,r,p,l,aar,w,kox,j
+l,d,v,pp,q,j,bxip,w,i,im,qa,o	e,o	h,w,a,a,qzj,nt,qfn,ut,fvhu,ts	hu,q,g,p,q,ofpje,fsqa,frp,p,vih,j,w,k,jx,	ln,th,ka,l,b,vgk,rv,hkx	rj,v,y,cwm,rao,e,l,wvr,ptc,lm,yg,u,k,i,b,zk,b,gv,fls
+velxtnhlyuysbnlchosqlhkozkdapjaueexjwrndwb	nglvnv	kqiv	pbshwlmcexdzipopxjyrxhvjalwp	pydvipwlkkpdvbtepahskwuornbsb	qwbacgq
+l,y,u,bf,y,m,eals,n,cop,h,g,vs,jga,opt	x,b,zwmn,hh,b,n,pdj,t,d	px	yn,vtd,u,y,b,ps,yo,qqnem,mxg,m,al,rd,c,k,d,q,f	ilxdxa,m,y,,p,p,y,prgmg,q,n,etj,k,ns	b,pl,z,jq,hk
+p,gc	jn,mzr,bw	sb,e,r,dy,ur,wzy,r,c,n,yglr,jbdu,r,pqk,k	q,d,,,p,l,euhl,dc,rwh,t,tq,z,h,p,s,t,x,fugr,h	wi,zxb,jcig,o,t,k	mfh,ym,h,e,p,cnvx,uv,zx,x,pq,blt,v,r,u,tr,g,g,xt
+nri,p,,t,if,,y,ptlqq	a,i	w,ovli,um,w,f,re,k,sb,w,jy,zf	i,g,p,q,mii,nr,jm,cc	i,szl,k,eg,l,d	,ah,w,b,vh
+,,sh,wx,mn,xm,u,d,yy,u,t,m,j,s,b	ogadq,g,y,y,i,h,ln,jda,g,cz,s,rv,r,s,s,le,r,	y,nu,f,nagj	o,h,,adfy,o,nf,ns,gvsvnub,k,b,xyz	v,h,g,ef,y,gb	c,x,cw,x,go,h,t,x,cu,u,qgrqzrcmn,kq,cd,g,rejp,zcq
+skxg,t,vay,d,wug,d,xg,sexc	rt	g,ag,mjq,fjnyji,iwa,m,ml,b,ua,b,qjxeoc	be,s,sh,n,jbzxs,g,n,i,h,y,r,be,mfo,u,p	cw,r,,u,zn,eg,r,yac,m,l,edkr,ha,x,g,b,c,tg,c	j,ye,u,ejd,maj,ea,bm,u,iy`,
+			expectedDelimiter: '\t',
+		},
+		// case 13 - a CSV with more than 10 lines and since we only use the first 10 lines, it should still get the delimiter as semicolon
+		{
+			csv: `col1;col2;col3
+1;1;1
+2;2;2
+3;3;3
+4;4;4
+5;5;5
+6;6;6
+7;7;7
+8;8;8
+9;9;9
+10;10;10
+11	11	11
+12|12|12`,
+			expectedDelimiter: ';',
+		},
+		// case 14 - a really long single line (over 10k) that will get truncated, but since it has commas and semicolons (but more semicolons) it will pick semicolon
+		{
+			csv:               strings.Repeat("a;b,c;", 1700),
+			expectedDelimiter: ';',
+		},
+		// case 15 - 2 lines that are well over 10k, but since the 2nd line is where this CSV will be truncated (10k sample), it will only use the first line, so semicolon will be picked
+		{
+			csv:               "col1@col2@col3\na@b@" + strings.Repeat("c", 6000) + "\nd,e," + strings.Repeat("f", 4000),
+			expectedDelimiter: '@',
+		},
+		// case 16 - has all delimiters so should return comma
+		{
+			csv: `col1,col2;col3@col4|col5	col6
+a	b|c@d;e,f`,
+			expectedDelimiter: ',',
+		},
+		// case 16 - nothing works (bad csv) so returns comma by default
+		{
+			csv: `col1,col2
+a;b
+c@e
+f	g
+h|i
+jkl`,
+			expectedDelimiter: ',',
+		},
+	}
+
+	for n, c := range cases {
+		delimiter := guessDelimiter([]byte(decodeSlashes(t, c.csv)))
+		assert.EqualValues(t, c.expectedDelimiter, delimiter, "case %d: delimiter should be equal, expected '%c' got '%c'", n, c.expectedDelimiter, delimiter)
+	}
+}
+
+func TestGuessFromBeforeAfterQuotes(t *testing.T) {
+	cases := []struct {
+		csv               string
+		expectedDelimiter rune
+	}{
+		// case 0 - tab delimited with new lines in values, commas in values
+		{
+			csv: `1	"some,""more
+""
+	quoted,
+text,"	a
+2	"some,
+quoted,\t
+	text,"	b
+3	"some,
+quoted,
+	text"	c
+4	"some,
+quoted,
+text,"	d`,
+			expectedDelimiter: '\t',
+		},
+		// case 1 - semicolon delmited with quotes and semicolon in value
+		{
+			csv: `col1;col2
+"this has a literal "" in the text";"and an ; in the text"`,
+			expectedDelimiter: ';',
+		},
+		// case 2 - pipe delimited with quotes
+		{
+			csv: `Col1 | Col2 | Col3
+abc   | "Hello
+World"|123
+"de
+|
+f" | 4.56 | 789`,
+			expectedDelimiter: '|',
+		},
+		// case 3 - a complicated quoted CSV that is semicolon delmiited
+		{
+			csv: `he; she
+"he said, ""hey!"""; "she said, ""hey back!"""
+but; "be"`,
+			expectedDelimiter: ';',
+		},
+		// case 4 - no delimiter should be found
+		{
+			csv:               `a,b`,
+			expectedDelimiter: 0,
+		},
+		// case 5 - no limiter should be found
+		{
+			csv: `col1
+"he said, ""here I am"""`,
+			expectedDelimiter: 0,
+		},
+		// case 6 - delimiter before double quoted string with space
+		{
+			csv: `col1|col2
+a| "he said, ""here I am"""`,
+			expectedDelimiter: '|',
+		},
+		// case 7 - delimiter before double quoted string without space
+		{
+			csv: `col1|col2
+a|"he said, ""here I am"""`,
+			expectedDelimiter: '|',
+		},
+		// case 8 - delimiter after double quoted string with space
+		{
+			csv: `col1, col2
+"abc\n
+
+", def`,
+			expectedDelimiter: ',',
+		},
+		// case 9 - delimiter after double quoted string without space
+		{
+			csv: `col1,col2
+"abc\n
+
+",def`,
+			expectedDelimiter: ',',
+		},
+	}
+
+	for n, c := range cases {
+		delimiter := guessFromBeforeAfterQuotes([]byte(decodeSlashes(t, c.csv)))
+		assert.EqualValues(t, c.expectedDelimiter, delimiter, "case %d: delimiter should be equal, expected '%c' got '%c'", n, c.expectedDelimiter, delimiter)
+	}
+}
+
+func TestFormatError(t *testing.T) {
+	cases := []struct {
+		err             error
+		expectedMessage string
+		expectsError    bool
+	}{
+		{
+			err: &csv.ParseError{
+				Err: csv.ErrFieldCount,
+			},
+			expectedMessage: "repo.error.csv.invalid_field_count",
+			expectsError:    false,
+		},
+		{
+			err: &csv.ParseError{
+				Err: csv.ErrBareQuote,
+			},
+			expectedMessage: "repo.error.csv.unexpected",
+			expectsError:    false,
+		},
+		{
+			err:          bytes.ErrTooLarge,
+			expectsError: true,
+		},
+	}
+
+	for n, c := range cases {
+		message, err := FormatError(c.err, &translation.MockLocale{})
+		if c.expectsError {
+			require.Error(t, err, "case %d: expected an error to be returned", n)
+		} else {
+			require.NoError(t, err, "case %d: no error was expected, got error: %v", n, err)
+			assert.EqualValues(t, c.expectedMessage, message, "case %d: messages should be equal, expected '%s' got '%s'", n, c.expectedMessage, message)
+		}
+	}
+}