Add recursive selector

f3ath · Jul 28, 2020 · b9e7eef · b9e7eef
1 parent 4924dde
commit b9e7eef
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Showing 7 changed files with 92 additions and 38 deletions.
diff --git a/lib/src/json_path.dart b/lib/src/json_path.dart
@@ -11,7 +11,7 @@ class JsonPath {
     for (final node in Node.build(tokenize(expression)).children) {
       state = state.process(node);
     }
-    return JsonPath._(state.filter);
+    return JsonPath._(state.selector);
   }
 
   JsonPath._(this._selector);

diff --git a/lib/src/quote.dart b/lib/src/quote.dart
@@ -0,0 +1,12 @@
+/// A single-quoted string.
+/// Example:
+/// `hello` => `'hello'`
+/// `i'm ok` => `'i\'m ok'`
+class Quote {
+  Quote(String value) : value = "'${value.replaceAll("'", r"\'")}'";
+
+  final String value;
+
+  @override
+  String toString() => value;
+}
diff --git a/lib/src/selector/field.dart b/lib/src/selector/field.dart
@@ -1,5 +1,6 @@
-import 'package:jessie/src/selector/selector.dart';
+import 'package:jessie/src/quote.dart';
 import 'package:jessie/src/result.dart';
+import 'package:jessie/src/selector/selector.dart';
 
 class Field extends Selector {
   Field(this.name);
@@ -12,5 +13,5 @@ class Field extends Selector {
       .map((r) => Result(r.value[name], r.path + toString()));
 
   @override
-  String get expression => "['$name']";
+  String get expression => '[${Quote(name)}]';
 }
diff --git a/lib/src/selector/recursive.dart b/lib/src/selector/recursive.dart
@@ -0,0 +1,25 @@
+import 'package:jessie/src/quote.dart';
+import 'package:jessie/src/result.dart';
+import 'package:jessie/src/selector/selector.dart';
+
+class Recursive extends Selector {
+  @override
+  Iterable<Result> call(Iterable<Result> results) => results.map((r) {
+        final val = r.value;
+        final self = [r];
+        if (val is Map) {
+          return self.followedBy(call(val.entries
+              .map((e) => Result(e.value, r.path + '[${Quote(e.key)}]'))));
+        }
+        if (val is List) {
+          return self.followedBy(call(val
+              .asMap()
+              .entries
+              .map((e) => Result(e.value, r.path + '[${e.key}]'))));
+        }
+        return <Result>[];
+      }).expand((_) => _);
+
+  @override
+  String get expression => '..';
+}
diff --git a/lib/src/state.dart b/lib/src/state.dart
@@ -1,51 +1,54 @@
 import 'package:jessie/src/ast.dart';
 import 'package:jessie/src/selector/all_in_array.dart';
 import 'package:jessie/src/selector/field.dart';
-import 'package:jessie/src/selector/selector.dart';
 import 'package:jessie/src/selector/index.dart';
+import 'package:jessie/src/selector/recursive.dart';
+import 'package:jessie/src/selector/selector.dart';
 
 abstract class State {
   State process(Node node);
 
-  Selector get filter;
+  Selector get selector;
 }
 
 class Ready implements State {
-  Ready(this.filter);
+  Ready(this.selector);
 
   @override
-  final Selector filter;
+  final Selector selector;
 
   @override
   State process(Node node) {
     if (node.value == '[') {
-      return Ready(filter.then(_brackets(node.children)));
+      return Ready(selector.then(_brackets(node.children)));
     }
     if (node.value == '.') {
-      return AwaitingField(filter);
+      return AwaitingField(selector);
+    }
+    if (node.value == '..') {
+      return Ready(selector.then(Recursive()));
     }
     throw StateError('Got ${node.value} in $this');
   }
 
   Selector _brackets(List<Node> nodes) {
     if (nodes.length == 1) {
       final node = nodes.single;
-      final val = node.value;
-      if (val == '*') return AllInArray();
+      if (node.value == '*') return AllInArray();
       if (node.isNumber) return Index(int.parse(nodes.first.value));
     }
     throw StateError('Unexpected bracket expression');
   }
 }
 
 class AwaitingField implements State {
-  AwaitingField(this.filter);
+  AwaitingField(this.selector);
 
   @override
-  final Selector filter;
+  final Selector selector;
 
   @override
   State process(Node node) {
-    return Ready(filter.then(Field(node.value)));
+    return Ready(selector.then(Field(node.value)));
   }
 }
diff --git a/lib/src/tokenize.dart b/lib/src/tokenize.dart
@@ -10,7 +10,7 @@ List<String> tokenize(String expr) {
           break;
         }
         if (expr.length > pos + 1) {
-          final nextTwoChars = expr.substring(pos, pos + 1);
+          final nextTwoChars = expr[pos] + expr[pos + 1];
           if (_doubles.contains(nextTwoChars)) {
             token = nextTwoChars;
             pos += 2;

diff --git a/test/json_path_test.dart b/test/json_path_test.dart
@@ -8,41 +8,54 @@ void main() {
   final json = jsonDecode(File('test/store.json').readAsStringSync());
   group('Basic expressions', () {
     test('Empty', () {
-      final path = JsonPath('');
-      expect(path.toString(), r'$');
-      expect(path.select(json).single.value, json);
-      expect(path.select(json).single.path, r'$');
+      final empty = JsonPath('');
+      expect(empty.toString(), r'$');
+      expect(empty.select(json).single.value, json);
+      expect(empty.select(json).single.path, r'$');
     });
 
     test('Only root', () {
-      final path = JsonPath(r'$');
-      expect(path.toString(), r'$');
-      expect(path.select(json).single.value, json);
-      expect(path.select(json).single.path, r'$');
+      final root = JsonPath(r'$');
+      expect(root.toString(), r'$');
+      expect(root.select(json).single.value, json);
+      expect(root.select(json).single.path, r'$');
     });
 
     test('Single field', () {
-      final path = JsonPath(r'$.store');
-      expect(path.toString(), r"$['store']");
-      expect(path.select(json).single.value, json['store']);
-      expect(path.select(json).single.path, r"$['store']");
+      final store = JsonPath(r'$.store');
+      expect(store.toString(), r"$['store']");
+      expect(store.select(json).single.value, json['store']);
+      expect(store.select(json).single.path, r"$['store']");
     });
 
     test('Path with an index', () {
-      final path = JsonPath(r'$.store.book[0].title');
-      expect(path.toString(), r"$['store']['book'][0]['title']");
-      expect(path.select(json).single.value, 'Sayings of the Century');
-      expect(path.select(json).single.path, r"$['store']['book'][0]['title']");
+      final firstBookTitle = JsonPath(r'$.store.book[0].title');
+      expect(firstBookTitle.toString(), r"$['store']['book'][0]['title']");
+      expect(
+          firstBookTitle.select(json).single.value, 'Sayings of the Century');
+      expect(firstBookTitle.select(json).single.path,
+          r"$['store']['book'][0]['title']");
     });
 
     test('All in array', () {
-      final path = JsonPath(r'$.store.book[*]');
-      expect(path.toString(), r"$['store']['book'][*]");
-      expect(path.select(json).length, 4);
-      expect(path.select(json).first.value, json['store']['book'][0]);
-      expect(path.select(json).first.path, r"$['store']['book'][0]");
-      expect(path.select(json).last.value, json['store']['book'][3]);
-      expect(path.select(json).last.path, r"$['store']['book'][3]");
+      final allBooksInStore = JsonPath(r'$.store.book[*]');
+      expect(allBooksInStore.toString(), r"$['store']['book'][*]");
+      expect(allBooksInStore.select(json).length, 4);
+      expect(
+          allBooksInStore.select(json).first.value, json['store']['book'][0]);
+      expect(allBooksInStore.select(json).first.path, r"$['store']['book'][0]");
+      expect(allBooksInStore.select(json).last.value, json['store']['book'][3]);
+      expect(allBooksInStore.select(json).last.path, r"$['store']['book'][3]");
+    });
+
+    test('Recursive', () {
+      final everything = JsonPath(r'$..');
+      expect(everything.toString(), r'$..');
+      expect(everything.select(json).length, 8);
+      expect(everything.select(json).first.value, json);
+      expect(everything.select(json).first.path, r'$');
+      expect(everything.select(json).last.value, json['store']['bicycle']);
+      expect(everything.select(json).last.path, r"$['store']['bicycle']");
     });
   });
 }