From a95be1943d57fc0187109434911ca09b821e1e96 Mon Sep 17 00:00:00 2001
From: debugtalk <mail@debugtalk.com>
Date: Wed, 29 Sep 2021 13:10:09 +0800
Subject: [PATCH] feat: use 28586 to escape $ notation

---
 parser.go      |  8 ++++++++
 parser_test.go | 16 ++++++++++++----
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/parser.go b/parser.go
index e3800de7..01c9d04a 100644
--- a/parser.go
+++ b/parser.go
@@ -69,6 +69,14 @@ func parseString(raw string, variablesMapping map[string]interface{}) interface{
 		parsedString += remainedString[0:startPosition]
 		remainedString = remainedString[startPosition:]
 
+		// search $$, use $$ to escape $ notation
+		if strings.HasPrefix(remainedString, "$$") { // found $$
+			matchStartPosition += 2
+			parsedString += "$"
+			remainedString = remainedString[2:]
+			continue
+		}
+
 		// search variable like ${var} or $var
 		varMatched := regexCompileVariable.FindStringSubmatch(remainedString)
 		if len(varMatched) == 3 {
diff --git a/parser_test.go b/parser_test.go
index 1de295aa..bbf29c48 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -109,10 +109,18 @@ func TestParseDataStringWithVariablesAbnormal(t *testing.T) {
 		expr   string
 		expect interface{}
 	}{
-		{"ABC$var_1{", "ABCabc{"},
-		{"{ABC$var_1{}a}", "{ABCabc{}a}"},
-		{"AB{C$var_1{}a}", "AB{Cabc{}a}"},
-		{"ABC$var_1}", "ABCabc}"},
+		{"ABC$var_1{", "ABCabc{"},         // {
+		{"ABC$var_1}", "ABCabc}"},         // }
+		{"{ABC$var_1{}a}", "{ABCabc{}a}"}, // {xx}
+		{"AB{C$var_1{}a}", "AB{Cabc{}a}"}, // {xx{}x}
+		{"ABC$$var_1{", "ABC$var_1{"},     // $$
+		{"ABC$$$var_1{", "ABC$abc{"},      // $$$
+		{"ABC$$$$var_1{", "ABC$$var_1{"},  // $$$$
+		{"ABC$var_1${", "ABCabc${"},       // ${
+		{"ABC$var_1${a", "ABCabc${a"},     // ${
+		{"ABC$var_1$}a", "ABCabc$}a"},     // $}
+		{"ABC$var_1}{a", "ABCabc}{a"},     // }{
+		{"ABC$var_1{}a", "ABCabc{}a"},     // {}
 	}
 
 	for _, data := range testData {