From f2df756c175d7a568d6650a54062db595b104533 Mon Sep 17 00:00:00 2001
From: yusing <yusing@6uo.me>
Date: Sat, 11 Jan 2025 02:14:22 +0800
Subject: [PATCH] fix rule parser

---
 internal/route/rules/parser.go      | 55 +++++++++++------
 internal/route/rules/parser_test.go | 96 +++++++++++++++++++++++++++++
 2 files changed, 132 insertions(+), 19 deletions(-)
 create mode 100644 internal/route/rules/parser_test.go

diff --git a/internal/route/rules/parser.go b/internal/route/rules/parser.go
index ac51ebf..653c150 100644
--- a/internal/route/rules/parser.go
+++ b/internal/route/rules/parser.go
@@ -1,7 +1,8 @@
 package rules
 
 import (
-	"strings"
+	"bytes"
+	"unicode"
 
 	E "github.com/yusing/go-proxy/internal/error"
 )
@@ -22,15 +23,30 @@ var escapedChars = map[rune]rune{
 //	error 403 "Forbidden 'foo' 'bar'"
 //	error 403 Forbidden\ \"foo\"\ \"bar\".
 func parse(v string) (subject string, args []string, err E.Error) {
-	v = strings.TrimSpace(v)
-	var buf strings.Builder
+	buf := bytes.NewBuffer(make([]byte, 0, len(v)))
+
 	escaped := false
-	quotes := make([]rune, 0, 4)
-	flush := func() {
+	quote := rune(0)
+	flush := func(quoted bool) {
+		part := buf.String()
+		if !quoted {
+			beg := 0
+			for i, r := range part {
+				if unicode.IsSpace(r) {
+					beg = i + 1
+				} else {
+					break
+				}
+			}
+			if beg == len(part) { // all spaces
+				return
+			}
+			part = part[beg:] // trim leading spaces
+		}
 		if subject == "" {
-			subject = buf.String()
+			subject = part
 		} else {
-			args = append(args, buf.String())
+			args = append(args, part)
 		}
 		buf.Reset()
 	}
@@ -51,29 +67,30 @@ func parse(v string) (subject string, args []string, err E.Error) {
 			continue
 		case '"', '\'':
 			switch {
-			case len(quotes) > 0 && quotes[len(quotes)-1] == r:
-				quotes = quotes[:len(quotes)-1]
-				if len(quotes) == 0 {
-					flush()
-				} else {
-					buf.WriteRune(r)
-				}
-			case len(quotes) == 0:
-				quotes = append(quotes, r)
+			case quote == 0:
+				quote = r
+				flush(false)
+			case r == quote:
+				quote = 0
+				flush(true)
 			default:
 				buf.WriteRune(r)
 			}
 		case ' ':
-			flush()
+			if quote == 0 {
+				flush(false)
+				continue
+			}
+			fallthrough
 		default:
 			buf.WriteRune(r)
 		}
 	}
 
-	if len(quotes) > 0 {
+	if quote != 0 {
 		err = ErrUnterminatedQuotes
 	} else {
-		flush()
+		flush(false)
 	}
 	return
 }
diff --git a/internal/route/rules/parser_test.go b/internal/route/rules/parser_test.go
new file mode 100644
index 0000000..b560ef4
--- /dev/null
+++ b/internal/route/rules/parser_test.go
@@ -0,0 +1,96 @@
+package rules
+
+import (
+	"strconv"
+	"testing"
+
+	E "github.com/yusing/go-proxy/internal/error"
+	. "github.com/yusing/go-proxy/internal/utils/testing"
+)
+
+func TestParser(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		subject string
+		args    []string
+		wantErr E.Error
+	}{
+		{
+			name:    "basic",
+			input:   "rewrite / /foo/bar",
+			subject: "rewrite",
+			args:    []string{"/", "/foo/bar"},
+		},
+		{
+			name:    "with quotes",
+			input:   `error 403 "Forbidden 'foo' 'bar'."`,
+			subject: "error",
+			args:    []string{"403", "Forbidden 'foo' 'bar'."},
+		},
+		{
+			name:    "with quotes 2",
+			input:   `basic_auth "username" "password"`,
+			subject: "basic_auth",
+			args:    []string{"username", "password"},
+		},
+		{
+			name:    "with escaped",
+			input:   `foo bar\ baz bar\r\n\tbaz bar\'\"baz`,
+			subject: "foo",
+			args:    []string{"bar baz", "bar\r\n\tbaz", `bar'"baz`},
+		},
+		{
+			name:    "empty string",
+			input:   `foo '' ""`,
+			subject: "foo",
+			args:    []string{"", ""},
+		},
+		{
+			name:    "invalid_escape",
+			input:   `foo \bar`,
+			wantErr: ErrUnsupportedEscapeChar,
+		},
+		{
+			name:    "chaos",
+			input:   `error 403 "Forbidden "foo" "bar""`,
+			subject: "error",
+			args:    []string{"403", "Forbidden ", "foo", " ", "bar", ""},
+		},
+		{
+			name:    "chaos2",
+			input:   `foo "'bar' 'baz'" abc\ 'foo "bar"'.`,
+			subject: "foo",
+			args:    []string{"'bar' 'baz'", "abc ", `foo "bar"`, "."},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			subject, args, err := parse(tt.input)
+			if tt.wantErr != nil {
+				ExpectError(t, tt.wantErr, err)
+				return
+			}
+			// t.Log(subject, args, err)
+			ExpectNoError(t, err)
+			ExpectEqual(t, subject, tt.subject)
+			ExpectEqual(t, len(args), len(tt.args))
+			for i, arg := range args {
+				ExpectEqual(t, arg, tt.args[i])
+			}
+		})
+	}
+	t.Run("unterminated quotes", func(t *testing.T) {
+		tests := []string{
+			`error 403 "Forbidden 'foo' 'bar'`,
+			`error 403 "Forbidden 'foo 'bar'`,
+			`error 403 "Forbidden foo "bar'"`,
+		}
+		for i, test := range tests {
+			t.Run(strconv.Itoa(i), func(t *testing.T) {
+				_, _, err := parse(test)
+				ExpectError(t, ErrUnterminatedQuotes, err)
+			})
+		}
+	})
+}