Fixed modifier pipe issue

This commit fixes an issue where chaining modifiers that used a
string arg would fail to process the modifier following the first.

fixes #143

gjson.go

@@ -464,11 +464,13 @@ func ParseBytes(json []byte) Result {
 }
 
 func squash(json string) string {
-	// expects that the lead character is a '[' or '{' or '('
+	// expects that the lead character is a '[' or '{' or '(' or '"'
 	// squash the value, ignoring all nested arrays and objects.
-	// the first '[' or '{' or '(', has already been read
-	depth := 1
-	for i := 1; i < len(json); i++ {
+	var i, depth int
+	if json[0] != '"' {
+		i, depth = 1, 1
+	}
+	for ; i < len(json); i++ {
 		if json[i] >= '"' && json[i] <= '}' {
 			switch json[i] {
 			case '"':
@@ -495,6 +497,9 @@ func squash(json string) string {
 						break
 					}
 				}
+				if depth == 0 {
+					return json[:i+1]
+				}
 			case '{', '[', '(':
 				depth++
 			case '}', ']', ')':
@@ -2713,7 +2718,7 @@ func execModifier(json, path string) (pathOut, res string, ok bool) {
 			case '{', '[', '"':
 				res := Parse(pathOut)
 				if res.Exists() {
-					_, args = parseSquash(pathOut, 0)
+					args = squash(pathOut)
 					pathOut = pathOut[len(args):]
 					parsedArgs = true
 				}

gjson_test.go

@@ -2023,3 +2023,20 @@ func TestIssue141(t *testing.T) {
 	assert(t, Get(json, "data.#.{q}|@ugly").Raw == `[{"q":11},{"q":21},{"q":31}]`)
 	assert(t, Get(json, "data.#.q|@ugly").Raw == `[11,21,31]`)
 }
+
+func TestChainedModifierStringArgs(t *testing.T) {
+	// issue #143
+	AddModifier("push", func(json, arg string) string {
+		json = strings.TrimSpace(json)
+		if len(json) < 2 || !Parse(json).IsArray() {
+			return json
+		}
+		json = strings.TrimSpace(json[1 : len(json)-1])
+		if len(json) == 0 {
+			return "[" + arg + "]"
+		}
+		return "[" + json + "," + arg + "]"
+	})
+	res := Get("[]", `@push:"2"|@push:"3"|@push:{"a":"b","c":["e","f"]}|@push:true|@push:10.23`)
+	assert(t, res.String() == `["2","3",{"a":"b","c":["e","f"]},true,10.23]`)
+}