From ec3137baf34471af66654490e4692626a17911c8 Mon Sep 17 00:00:00 2001
From: Richard Mahn <richmahn@users.noreply.github.com>
Date: Tue, 26 Oct 2021 11:15:37 -0400
Subject: [PATCH 1/4] Fixes #16559 - Do not trim leading spaces for tab
 delimited

---
 modules/csv/csv.go      |  6 ++++-
 modules/csv/csv_test.go | 51 +++++++++++++++++++++++++++++++++++------
 2 files changed, 49 insertions(+), 8 deletions(-)

diff --git a/modules/csv/csv.go b/modules/csv/csv.go
index c239c7f647ace..cba23ec8d9df7 100644
--- a/modules/csv/csv.go
+++ b/modules/csv/csv.go
@@ -22,7 +22,11 @@ var quoteRegexp = regexp.MustCompile(`["'][\s\S]+?["']`)
 func CreateReader(input io.Reader, delimiter rune) *stdcsv.Reader {
 	rd := stdcsv.NewReader(input)
 	rd.Comma = delimiter
-	rd.TrimLeadingSpace = true
+	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
 }
 
diff --git a/modules/csv/csv_test.go b/modules/csv/csv_test.go
index 3cc09c40aa5b3..f1d857fd3e12e 100644
--- a/modules/csv/csv_test.go
+++ b/modules/csv/csv_test.go
@@ -18,15 +18,52 @@ func TestCreateReader(t *testing.T) {
 }
 
 func TestCreateReaderAndGuessDelimiter(t *testing.T) {
-	input := "a;b;c\n1;2;3\n4;5;6"
+	var csvToRowsMap = map[string][][]string{
+		`col1	col2	col3
+a	b	c
+	e	f
+g	h	i
+j		l
+m	n	
+p	q	r
+		u
+v	w	x
+y		
+		`: {{"col1", "col2", "col3"},
+			{"a", "b", "c"},
+			{"", "e", "f"},
+			{"g", "h", "i"},
+			{"j", "", "l"},
+			{"m", "n", ""},
+			{"p", "q", "r"},
+			{"", "", "u"},
+			{"v", "w", "x"},
+			{"y", "", ""},
+			{"", "", ""}},
+		` col1,col2,col3
+ a, b, c
+d,e,f
+ ,h, i
+j, , 
+ , , `: {{"col1", "col2", "col3"},
+			{"a", "b", "c"},
+			{"d", "e", "f"},
+			{"", "h", "i"},
+			{"j", "", ""},
+			{"", "", ""}},
+	}
 
-	rd, err := CreateReaderAndGuessDelimiter(strings.NewReader(input))
-	assert.NoError(t, err)
-	assert.Equal(t, ';', rd.Comma)
+	for csv, expectedRows := range csvToRowsMap {
+		rd, err := CreateReaderAndGuessDelimiter(strings.NewReader(csv))
+		assert.NoError(t, err)
+		rows, err := rd.ReadAll()
+		assert.NoError(t, err)
+		assert.EqualValues(t, rows, expectedRows)
+	}
 }
 
 func TestGuessDelimiter(t *testing.T) {
-	var kases = map[string]rune{
+	var csvToDelimiterMap = map[string]rune{
 		"a":                         ',',
 		"1,2":                       ',',
 		"1;2":                       ';',
@@ -37,7 +74,7 @@ func TestGuessDelimiter(t *testing.T) {
 		"<br/>":                     ',',
 	}
 
-	for k, v := range kases {
-		assert.EqualValues(t, guessDelimiter([]byte(k)), v)
+	for csv, expectedDelimiter := range csvToDelimiterMap {
+		assert.EqualValues(t, guessDelimiter([]byte(csv)), expectedDelimiter)
 	}
 }

From a4f0782acf345413f4fd7e0305ea7d1243788662 Mon Sep 17 00:00:00 2001
From: Richard Mahn <richmahn@users.noreply.github.com>
Date: Tue, 26 Oct 2021 11:31:22 -0400
Subject: [PATCH 2/4] Adds back semicolon delimited test

---
 modules/csv/csv_test.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/modules/csv/csv_test.go b/modules/csv/csv_test.go
index f1d857fd3e12e..ae50f114ffb21 100644
--- a/modules/csv/csv_test.go
+++ b/modules/csv/csv_test.go
@@ -19,6 +19,9 @@ func TestCreateReader(t *testing.T) {
 
 func TestCreateReaderAndGuessDelimiter(t *testing.T) {
 	var csvToRowsMap = map[string][][]string{
+		`a;b;c
+1;2;3
+4;5;6`: {{"a", "b", "c"}, {"1", "2", "3"}, {"4", "5", "6"}},
 		`col1	col2	col3
 a	b	c
 	e	f

From 18802c4b3a8653f4ff3fc77206bf148547e444d3 Mon Sep 17 00:00:00 2001
From: Richard Mahn <richmahn@users.noreply.github.com>
Date: Tue, 26 Oct 2021 11:51:43 -0400
Subject: [PATCH 3/4] Fixes linting

---
 modules/csv/csv_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/modules/csv/csv_test.go b/modules/csv/csv_test.go
index ae50f114ffb21..f71ce0f884f9c 100644
--- a/modules/csv/csv_test.go
+++ b/modules/csv/csv_test.go
@@ -43,7 +43,7 @@ y
 			{"v", "w", "x"},
 			{"y", "", ""},
 			{"", "", ""}},
-		` col1,col2,col3
+		`col1,col2,col3
  a, b, c
 d,e,f
  ,h, i

From ef4d82ebb1a29c27d9e6d5ec1bad5475c4883af8 Mon Sep 17 00:00:00 2001
From: Richard Mahn <richmahn@users.noreply.github.com>
Date: Tue, 26 Oct 2021 12:20:01 -0400
Subject: [PATCH 4/4] Adds nolint directive to test because uses strings
 starting with spaces

---
 modules/csv/csv_test.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/modules/csv/csv_test.go b/modules/csv/csv_test.go
index f71ce0f884f9c..9b7fa1f4fafc2 100644
--- a/modules/csv/csv_test.go
+++ b/modules/csv/csv_test.go
@@ -17,6 +17,7 @@ func TestCreateReader(t *testing.T) {
 	assert.Equal(t, ',', rd.Comma)
 }
 
+//nolint
 func TestCreateReaderAndGuessDelimiter(t *testing.T) {
 	var csvToRowsMap = map[string][][]string{
 		`a;b;c
@@ -43,7 +44,7 @@ y
 			{"v", "w", "x"},
 			{"y", "", ""},
 			{"", "", ""}},
-		`col1,col2,col3
+		` col1,col2,col3
  a, b, c
 d,e,f
  ,h, i