From 97dfab5df925a6bd5b32a08aeee52848f31a2396 Mon Sep 17 00:00:00 2001
From: f3ath <karapetov@gmail.com>
Date: Wed, 29 Jul 2020 20:54:00 -0700
Subject: [PATCH] Bracket field notation support

---
 CHANGELOG.md             |  3 +++
 README.md                |  2 +-
 lib/src/quote.dart       |  6 ++++--
 lib/src/tokenize.dart    | 43 ++++++++++++++++++++++++----------------
 test/json_path_test.dart | 28 +++++++++++++++++++++-----
 5 files changed, 57 insertions(+), 25 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8c69be3..07f1bb2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,7 @@
 ## [Unreleased]
+### Added
+- Bracket field notation support
+
 ## [0.0.0+dev.3] - 2020-07-28
 ### Added
 - Partial implementation of bracket field notation
diff --git a/README.md b/README.md
index 758a9ee..44430f9 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 - [x] Basic selectors: fields, indices
 - [x] Recursive descent (`$..`)
 - [x] Wildcard (`$.store.*`)
-- [ ] Square-bracket field notation (`['foo']`, `$['"some" \'special\' [chars]']`)
+- [x] Square-bracket field notation (`['foo']`, `$['"some" \'special\' [chars]']`)
 - [ ] Subscript (`books[:2]`)
 - [ ] Slice (`articles[1:10:2]`)
 - [ ] Union (`book[0, 1]`, `book[author, title, price]`)
diff --git a/lib/src/quote.dart b/lib/src/quote.dart
index 956c94c..e74ca1d 100644
--- a/lib/src/quote.dart
+++ b/lib/src/quote.dart
@@ -1,9 +1,11 @@
 /// A single-quoted string.
 /// Example:
 /// `hello` => `'hello'`
-/// `i'm ok` => `'i\'m ok'`
+/// `i'm \ok` => `'i\'m \\ok'`
 class Quote {
-  Quote(String value) : value = "'${value.replaceAll("'", r"\'")}'";
+  Quote(String value)
+      : value =
+            "'" + value.replaceAll(r'\', r'\\').replaceAll("'", r"\'") + "'";
 
   final String value;
 
diff --git a/lib/src/tokenize.dart b/lib/src/tokenize.dart
index 7b098f8..a6967c9 100644
--- a/lib/src/tokenize.dart
+++ b/lib/src/tokenize.dart
@@ -2,26 +2,45 @@
 List<String> tokenize(String expr) {
   final tokens = <String>[];
   var pos = 0;
+  var insideQuotedString = false;
   while (pos < expr.length) {
     var token = '';
     while (pos < expr.length) {
-      if (_singles.contains(expr[pos])) {
+      final char = expr[pos];
+      if (char == "'") {
+        insideQuotedString = !insideQuotedString;
+      }
+      if (insideQuotedString) {
+        if (char == r'\') {
+          if (expr.length <= pos + 1) throw FormatException('Dangling escape');
+          token += expr[pos + 1];
+          pos += 2;
+        } else {
+          token += char;
+          pos += 1;
+        }
+        continue;
+      }
+      if (_singles.contains(char)) {
         if (token.isNotEmpty) {
           break;
         }
         if (expr.length > pos + 1) {
-          final nextTwoChars = expr[pos] + expr[pos + 1];
+          final nextTwoChars = char + expr[pos + 1];
           if (_doubles.contains(nextTwoChars)) {
             token = nextTwoChars;
             pos += 2;
             break;
           }
         }
-        token = expr[pos++];
+        token = char;
+        pos += 1;
         break;
       }
-      token += expr[pos++];
+      token += char;
+      pos += 1;
     }
+    if (insideQuotedString) throw FormatException('Unmatched quote');
     tokens.add(token);
   }
   return tokens;
@@ -31,20 +50,10 @@ const _singles = [
   r'$',
   '[',
   ']',
-  '(',
-  ')',
-  '?',
   '.',
   '*',
-  '@',
-  '<',
-  '>',
-  '-',
-  '=',
-  '&',
-  '|',
-  ':',
-  ' '
 ];
 
-const _doubles = ['..', '&&', '||'];
+const _doubles = [
+  '..',
+];
diff --git a/test/json_path_test.dart b/test/json_path_test.dart
index fd52f48..9a477bf 100644
--- a/test/json_path_test.dart
+++ b/test/json_path_test.dart
@@ -38,11 +38,29 @@ void main() {
     test('Mixed brackets and fields', () {
       final store = JsonPath(r"$['store'].bicycle['price']");
       expect(store.toString(), r"$['store']['bicycle']['price']");
-      expect(store.select(json).single.value, json['store']['bicycle']['price']);
+      expect(
+          store.select(json).single.value, json['store']['bicycle']['price']);
       expect(store.select(json).single.path, r"$['store']['bicycle']['price']");
     });
   });
 
+  group('Invalid format', () {
+    test('Unmatched quote', () {
+      expect(() => JsonPath(r"$['hello"), throwsFormatException);
+      expect(() => JsonPath(r"$['hello\"), throwsFormatException);
+    });
+  });
+
+  group('Uncommon brackets', () {
+    test('Escape single quote', () {
+      final j = {r"sq'sq s\s qs\'qs": 'value'};
+      final path = JsonPath(r"$['sq\'sq s\\s qs\\\'qs']");
+      final select = path.select(j);
+      expect(select.single.value, 'value');
+      expect(select.single.path, r"$['sq\'sq s\\s qs\\\'qs']");
+    });
+  });
+
   group('Wildcards', () {
     test('All in root', () {
       final allInRoot = JsonPath(r'$.*');
@@ -87,10 +105,10 @@ void main() {
       final path = JsonPath(r'$..price');
       expect(path.toString(), r"$..['price']");
       expect(path.select(json).length, 5);
-//      expect(path.select(json).first.value, json['store']);
-//      expect(path.select(json).first.path, r"$['store']");
-//      expect(path.select(json).last.value, json['store']['bicycle']['price']);
-//      expect(path.select(json).last.path, r"$['store']['bicycle']['price']");
+      expect(path.select(json).first.value, json['store']['book'][0]['price']);
+      expect(path.select(json).first.path, r"$['store']['book'][0]['price']");
+      expect(path.select(json).last.value, json['store']['bicycle']['price']);
+      expect(path.select(json).last.path, r"$['store']['bicycle']['price']");
     });
   });