From 5f47e75ef99dd39e4fef777bc6981411da0fc1fc Mon Sep 17 00:00:00 2001
From: Caitlin Elfring <celfring@gmail.com>
Date: Wed, 21 Jul 2021 20:34:42 -0400
Subject: [PATCH] Use null terminator for masking inline ignore (#111)

* Add test for wokeignore inline in the beginning of the line

* Use a single byte (null terminator) character for masking inline ignore rule

* Rename function to be more clear
---
 pkg/result/lineresult_test.go |  2 ++
 pkg/rule/rule.go              | 14 +++++++-------
 pkg/rule/rule_test.go         |  6 +++---
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/pkg/result/lineresult_test.go b/pkg/result/lineresult_test.go
index 84e7b7e4..0fe612bc 100644
--- a/pkg/result/lineresult_test.go
+++ b/pkg/result/lineresult_test.go
@@ -22,6 +22,8 @@ func TestFindResults(t *testing.T) {
 	// inline-ignoring is handled in Parser.generateFileFindings, not FindResults
 	rs = FindResults(&rule.TestRule, "my/file", "this has the term whitelist #wokeignore:rule=whitelist", 1)
 	assert.Len(t, rs, 1)
+	rs = FindResults(&rule.TestRule, "my/file", "/* wokeignore:rule=whitelist */ this has the term whitelist", 1)
+	assert.Len(t, rs, 1)
 }
 
 func TestLineResult_MarshalJSON(t *testing.T) {
diff --git a/pkg/rule/rule.go b/pkg/rule/rule.go
index 0231a272..18482917 100644
--- a/pkg/rule/rule.go
+++ b/pkg/rule/rule.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"regexp"
 	"strings"
-	"unicode"
 
 	"github.com/get-woke/woke/pkg/util"
 )
@@ -34,7 +33,7 @@ func (r *Rule) FindMatchIndexes(text string) [][]int {
 	r.SetRegexp()
 
 	// Remove inline ignores from text to avoid matching against other rules
-	matches := r.re.FindAllStringSubmatchIndex(removeInlineIgnore(text), -1)
+	matches := r.re.FindAllStringSubmatchIndex(maskInlineIgnore(text), -1)
 	if matches == nil {
 		return [][]int(nil)
 	}
@@ -183,10 +182,10 @@ func escape(ss []string) []string {
 	return ss
 }
 
-// removeInlineIgnore removes the entire match of the ignoreRuleRegex from the line
-// and replaces it with the unicode replacement character so the rule matcher won't
-// attempt to find findings within
-func removeInlineIgnore(line string) string {
+// maskInlineIgnore removes the entire match of the ignoreRuleRegex from the line
+// and replaces it with the null terminator (\x00) character so the rule matcher won't
+// attempt to find findings within the inline ignore
+func maskInlineIgnore(line string) string {
 	inlineIgnoreMatch := ignoreRuleRegex.FindStringIndex(line)
 	if inlineIgnoreMatch == nil || len(inlineIgnoreMatch) < 2 {
 		return line
@@ -198,7 +197,8 @@ func removeInlineIgnore(line string) string {
 	end := inlineIgnoreMatch[1]
 
 	for i := start; i < end; i++ {
-		lineWithoutIgnoreRule[i] = unicode.ReplacementChar
+		// use null terminator to indicate a masked character
+		lineWithoutIgnoreRule[i] = rune(0)
 	}
 
 	return string(lineWithoutIgnoreRule)
diff --git a/pkg/rule/rule_test.go b/pkg/rule/rule_test.go
index ad7bce88..a8765a5d 100644
--- a/pkg/rule/rule_test.go
+++ b/pkg/rule/rule_test.go
@@ -162,7 +162,7 @@ func TestRule_regexString(t *testing.T) {
 	}
 }
 
-func Test_removeInlineIgnore(t *testing.T) {
+func Test_maskInlineIgnore(t *testing.T) {
 	tests := []struct {
 		desc     string
 		line     string
@@ -171,7 +171,7 @@ func Test_removeInlineIgnore(t *testing.T) {
 		{
 			desc:     "replace wokeignore:rule",
 			line:     "wokeignore:rule=master-slave",
-			expected: "����������������������������",
+			expected: "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
 		},
 		{
 			desc:     "not replace wokeignore:rule",
@@ -181,7 +181,7 @@ func Test_removeInlineIgnore(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.desc, func(t *testing.T) {
-			assert.Equal(t, tt.expected, removeInlineIgnore(tt.line))
+			assert.Equal(t, tt.expected, maskInlineIgnore(tt.line))
 		})
 	}
 }