1.0.0

README.md

@@ -2,9 +2,9 @@
 [![Pub](https://img.shields.io/pub/v/graphql_parser.svg)](https://pub.dartlang.org/packages/graphql_parser)
 [![build status](https://travis-ci.org/thosakwe/graphql_parser.svg)](https://travis-ci.org/thosakwe/graphql_parser)
 
-Parses GraphQL queries and schemas.
+Parses GraphQL queries and schemas. Also includes a `GraphQLVisitor` class.
 
-*This library is merely a parser*. Any sort of actual GraphQL API functionality must be implemented by you,
+*This library is merely a parser/visitor*. Any sort of actual GraphQL API functionality must be implemented by you,
 or by a third-party package.
 
 [Angel framework](https://angel-dart.github.io)

example/basic.dart

@@ -1,5 +1,4 @@
-import 'dart:async';
+import 'package:graphql_parser/graphql_parser.dart';
-import 'package:graphql_parser/src/language/language.dart';
 
 final String INPUT = '''
 {
@@ -13,4 +12,15 @@ final String INPUT = '''
 main() {
   var tokens = scan(INPUT);
   var parser = new Parser(tokens);
+  var doc = parser.parseDocument();
+
+  var operation = doc.definitions.first as OperationDefinitionContext;
+
+  var projectField = operation.selectionSet.selections.first.field;
+  print(projectField.fieldName.name); // project
+  print(projectField.arguments.first.name); // name
+  print(projectField.arguments.first.valueOrVariable.value.value); // GraphQL
+
+  var taglineField = projectField.selectionSet.selections.first.field;
+  print(taglineField.fieldName.name); // tagline
 }

example/visitor.dart

@@ -0,0 +1,50 @@
+import 'package:graphql_parser/graphql_parser.dart';
+import 'package:graphql_parser/visitor.dart';
+
+const String QUERY = '''
+{
+  foo,
+  baz: bar
+}
+''';
+
+const Map<String, dynamic> DATA = const {
+  'foo': 'hello',
+  'bar': 'world',
+  'quux': 'extraneous'
+};
+
+main() {
+  // Highly-simplified querying example...
+  var result = new MapQuerier(DATA).execute(QUERY);
+  print(result); // { foo: hello, baz: world }
+  print(result['foo']); // hello
+  print(result['baz']); // world
+}
+
+class MapQuerier extends GraphQLVisitor {
+  final Map<String, dynamic> data;
+  final Map<String, dynamic> result = {};
+
+  MapQuerier(this.data);
+
+  Map<String, dynamic> execute(String query) {
+    var doc = new Parser(scan(query)).parseDocument();
+    visitDocument(doc);
+    return result;
+  }
+
+  @override
+  visitField(FieldContext ctx) {
+    String realName, alias;
+    if (ctx.fieldName.alias == null)
+      realName = alias = ctx.fieldName.name;
+    else {
+      realName = ctx.fieldName.alias.name;
+      alias = ctx.fieldName.alias.alias;
+    }
+
+    // Set output field...
+    result[alias] = data[realName];
+  }
+}

lib/src/language/ast/alias.dart

@@ -7,15 +7,14 @@ class AliasContext extends Node {
 
   AliasContext(this.NAME1, this.COLON, this.NAME2);
 
-  /// The actual name of the value.
-  String get name => NAME1.text;
-
   /// The aliased name of the value.
-  String get alias => NAME2.text;
+  String get alias => NAME1.text;
+
+  /// The actual name of the value.
+  String get name => NAME2.text;
 
   @override
-  SourceSpan get span =>
+  SourceSpan get span => NAME1.span.union(COLON.span).union(NAME2.span);
-      new SourceSpan(NAME1.span?.start, NAME2.span?.end, toSource());
 
   @override
   String toSource() => '${NAME1.text}:${NAME2.text}';

lib/src/language/ast/node.dart

@@ -7,7 +7,4 @@ abstract class Node {
   SourceLocation get end => span.end;
 
   String toSource();
-
-  @override
-  String toString() => '${runtimeType}: ${toSource()}';
 }

lib/src/language/ast/operation_definition.dart

@@ -11,10 +11,10 @@ class OperationDefinitionContext extends DefinitionContext {
   final List<DirectiveContext> directives = [];
   final SelectionSetContext selectionSet;
 
-  bool get isMutation => TYPE.text == 'mutation';
+  bool get isMutation => TYPE?.text == 'mutation';
-  bool get isQuery => TYPE.text == 'query';
+  bool get isQuery => TYPE?.text == 'query';
 
-  String get name => NAME.text;
+  String get name => NAME?.text;
 
   OperationDefinitionContext(
       this.TYPE, this.NAME, this.variableDefinitions, this.selectionSet) {

lib/src/language/parser.dart

@@ -49,9 +49,69 @@ class Parser {
   DefinitionContext parseDefinition() =>
       parseOperationDefinition() ?? parseFragmentDefinition();
 
-  OperationDefinitionContext parseOperationDefinition() {}
+  OperationDefinitionContext parseOperationDefinition() {
+    var selectionSet = parseSelectionSet();
+    if (selectionSet != null)
+      return new OperationDefinitionContext(null, null, null, selectionSet);
+    else {
+      if (next(TokenType.MUTATION) || next(TokenType.QUERY)) {
+        var TYPE = current;
+        if (next(TokenType.NAME)) {
+          var NAME = current;
+          var variables = parseVariableDefinitions();
+          var dirs = parseDirectives();
+          var selectionSet = parseSelectionSet();
+          if (selectionSet != null)
+            return new OperationDefinitionContext(
+                TYPE, NAME, variables, selectionSet)
+              ..directives.addAll(dirs);
+          else
+            throw new SyntaxError.fromSourceLocation(
+                'Expected selection set in fragment definition.',
+                NAME.span.end);
+        } else
+          throw new SyntaxError.fromSourceLocation(
+              'Expected name after operation type "${TYPE.text}" in operation definition.',
+              TYPE.span.end);
+      } else
+        return null;
+    }
+  }
 
-  FragmentDefinitionContext parseFragmentDefinition() {}
+  FragmentDefinitionContext parseFragmentDefinition() {
+    if (next(TokenType.FRAGMENT)) {
+      var FRAGMENT = current;
+      if (next(TokenType.NAME)) {
+        var NAME = current;
+        if (next(TokenType.ON)) {
+          var ON = current;
+          var typeCondition = parseTypeCondition();
+          if (typeCondition != null) {
+            var dirs = parseDirectives();
+            var selectionSet = parseSelectionSet();
+            if (selectionSet != null)
+              return new FragmentDefinitionContext(
+                  FRAGMENT, NAME, ON, typeCondition, selectionSet)
+                ..directives.addAll(dirs);
+            else
+              throw new SyntaxError.fromSourceLocation(
+                  'Expected selection set in fragment definition.',
+                  typeCondition.span.end);
+          } else
+            throw new SyntaxError.fromSourceLocation(
+                'Expected type condition after "on" in fragment definition.',
+                ON.span.end);
+        } else
+          throw new SyntaxError.fromSourceLocation(
+              'Expected "on" after name "${NAME.text}" in fragment definition.',
+              NAME.span.end);
+      } else
+        throw new SyntaxError.fromSourceLocation(
+            'Expected name after "fragment" in fragment definition.',
+            FRAGMENT.span.end);
+    } else
+      return null;
+  }
 
   FragmentSpreadContext parseFragmentSpread() {
     if (next(TokenType.ELLIPSIS)) {
@@ -164,7 +224,27 @@ class Parser {
       return null;
   }
 
-  VariableDefinitionsContext parseVariableDefinitions() {}
+  VariableDefinitionsContext parseVariableDefinitions() {
+    if (next(TokenType.LPAREN)) {
+      var LPAREN = current;
+      List<VariableDefinitionContext> defs = [];
+      VariableDefinitionContext def = parseVariableDefinition();
+
+      while (def != null) {
+        defs.add(def);
+        maybe(TokenType.COMMA);
+        def = parseVariableDefinition();
+      }
+
+      if (next(TokenType.RPAREN))
+        return new VariableDefinitionsContext(LPAREN, current)
+          ..variableDefinitions.addAll(defs);
+      else
+        throw new SyntaxError.fromSourceLocation(
+            'Expected ")" after variable definitions.', LPAREN.span.end);
+    } else
+      return null;
+  }
 
   VariableDefinitionContext parseVariableDefinition() {
     var variable = parseVariable();

lib/visitor.dart

@@ -0,0 +1,125 @@
+import 'graphql_parser.dart';
+
+class GraphQLVisitor {
+  visitDocument(DocumentContext ctx) {
+    ctx.definitions.forEach(visitDefinition);
+  }
+
+  visitDefinition(DefinitionContext ctx) {
+    if (ctx is OperationDefinitionContext)
+      visitOperationDefinition(ctx);
+    else if (ctx is FragmentDefinitionContext) visitFragmentDefinition(ctx);
+  }
+
+  visitOperationDefinition(OperationDefinitionContext ctx) {
+    if (ctx.variableDefinitions != null)
+      visitVariableDefinitions(ctx.variableDefinitions);
+    ctx.directives.forEach(visitDirective);
+    visitSelectionSet(ctx.selectionSet);
+  }
+
+  visitFragmentDefinition(FragmentDefinitionContext ctx) {
+    visitTypeCondition(ctx.typeCondition);
+    ctx.directives.forEach(visitDirective);
+    visitSelectionSet(ctx.selectionSet);
+  }
+
+  visitSelectionSet(SelectionSetContext ctx) {
+    ctx.selections.forEach(visitSelection);
+  }
+
+  visitSelection(SelectionContext ctx) {
+    if (ctx.field != null) visitField(ctx.field);
+    if (ctx.fragmentSpread != null) visitFragmentSpread(ctx.fragmentSpread);
+    if (ctx.inlineFragment != null) visitInlineFragment(ctx.inlineFragment);
+  }
+
+  visitInlineFragment(InlineFragmentContext ctx) {
+    visitTypeCondition(ctx.typeCondition);
+    ctx.directives.forEach(visitDirective);
+    visitSelectionSet(ctx.selectionSet);
+  }
+
+  visitFragmentSpread(FragmentSpreadContext ctx) {
+    ctx.directives.forEach(visitDirective);
+  }
+
+  visitField(FieldContext ctx) {
+    visitFieldName(ctx.fieldName);
+    ctx.arguments.forEach(visitArgument);
+    ctx.directives.forEach(visitDirective);
+    if (ctx.selectionSet != null) ;
+    visitSelectionSet(ctx.selectionSet);
+  }
+
+  visitFieldName(FieldNameContext ctx) {
+    if (ctx.alias != null) visitAlias(ctx.alias);
+  }
+
+  visitAlias(AliasContext ctx) {}
+
+  visitDirective(DirectiveContext ctx) {
+    if (ctx.valueOrVariable != null) visitValueOrVariable(ctx.valueOrVariable);
+    if (ctx.argument != null) visitArgument(ctx.argument);
+  }
+
+  visitArgument(ArgumentContext ctx) {
+    visitValueOrVariable(ctx.valueOrVariable);
+  }
+
+  visitVariableDefinitions(VariableDefinitionsContext ctx) {
+    ctx.variableDefinitions.forEach(visitVariableDefinition);
+  }
+
+  visitVariableDefinition(VariableDefinitionContext ctx) {
+    visitVariable(ctx.variable);
+    visitType(ctx.type);
+    if (ctx.defaultValue != null) visitDefaultValue(ctx.defaultValue);
+  }
+
+  visitVariable(VariableContext ctx) {}
+
+  visitValueOrVariable(ValueOrVariableContext ctx) {
+    if (ctx.variable != null) visitVariable(ctx.variable);
+    if (ctx.value != null) visitValue(ctx.value);
+  }
+
+  visitDefaultValue(DefaultValueContext ctx) {
+    visitValue(ctx.value);
+  }
+
+  visitValue(ValueContext ctx) {
+    if (ctx is StringValueContext)
+      visitStringValue(ctx);
+    else if (ctx is NumberValueContext)
+      visitNumberValue(ctx);
+    else if (ctx is BooleanValueContext)
+      visitBooleanValue(ctx);
+    else if (ctx is ArrayValueContext) visitArrayValue(ctx);
+  }
+
+  visitStringValue(StringValueContext ctx) {}
+
+  visitBooleanValue(BooleanValueContext ctx) {}
+
+  visitNumberValue(NumberValueContext ctx) {}
+
+  visitArrayValue(ArrayValueContext ctx) {
+    ctx.values.forEach(visitValue);
+  }
+
+  visitTypeCondition(TypeConditionContext ctx) {
+    visitTypeName(ctx.typeName);
+  }
+
+  visitType(TypeContext ctx) {
+    if (ctx.typeName != null) visitTypeName(ctx.typeName);
+    if (ctx.listType != null) visitListType(ctx.listType);
+  }
+
+  visitListType(ListTypeContext ctx) {
+    visitType(ctx.type);
+  }
+
+  visitTypeName(TypeNameContext ctx) {}
+}

pubspec.yaml

@@ -1,5 +1,5 @@
 name: graphql_parser
-version: 0.0.0
+version: 1.0.0
 description: Parses GraphQL queries and schemas.
 author: Tobe O <thosakwe@gmail.com>
 homepage: https://github.com/thosakwe/graphql_parser

test/all.dart

@@ -1,6 +1,7 @@
 import 'package:test/test.dart';
 import 'argument_test.dart' as argument;
 import 'directive_test.dart' as directive;
+import 'document_test.dart' as document;
 import 'field_test.dart' as field;
 import 'fragment_spread_test.dart' as fragment_spread;
 import 'inline_fragment_test.dart' as inline_fragment;
@@ -13,6 +14,7 @@ import 'variable_test.dart' as variable;
 main() {
   group('argument', argument.main);
   group('directive', directive.main);
+  group('document', document.main);
   group('field', field.main);
   group('fragment spread', fragment_spread.main);
   group('inline fragment', inline_fragment.main);

test/document_test.dart

@@ -0,0 +1,100 @@
+import 'package:graphql_parser/graphql_parser.dart';
+import 'package:test/test.dart';
+import 'common.dart';
+import 'directive_test.dart';
+import 'field_test.dart';
+import 'selection_set_test.dart';
+import 'type_test.dart';
+import 'value_test.dart';
+import 'variable_definition_test.dart';
+
+main() {
+  test('fragment', () {
+    var fragment = parse('''
+    fragment PostInfo on Post {
+      description
+      comments {
+        id
+      }
+    }
+    ''').parseFragmentDefinition();
+
+    expect(fragment, isNotNull);
+    expect(fragment.name, 'PostInfo');
+    expect(fragment.typeCondition.typeName.name, 'Post');
+    expect(
+        fragment.selectionSet,
+        isSelectionSet([
+          isField(fieldName: isFieldName('description')),
+          isField(
+              fieldName: isFieldName('comments'),
+              selectionSet:
+                  isSelectionSet([isField(fieldName: isFieldName('id'))])),
+        ]));
+  });
+
+  test('fragment exceptions', () {
+    expect(
+        () => parse('fragment').parseFragmentDefinition(), throwsSyntaxError);
+    expect(() => parse('fragment foo').parseFragmentDefinition(),
+        throwsSyntaxError);
+    expect(() => parse('fragment foo on').parseFragmentDefinition(),
+        throwsSyntaxError);
+    expect(() => parse('fragment foo on bar').parseFragmentDefinition(),
+        throwsSyntaxError);
+  });
+
+  group('operation', () {
+    test('with selection set', () {
+      var op = parse('{foo, bar: baz}').parseOperationDefinition();
+      expect(op.variableDefinitions, isNull);
+      expect(op.isQuery, isFalse);
+      expect(op.isMutation, isFalse);
+      expect(op.name, isNull);
+      expect(
+          op.selectionSet,
+          isSelectionSet([
+            isField(fieldName: isFieldName('foo')),
+            isField(fieldName: isFieldName('bar', alias: 'baz'))
+          ]));
+    });
+
+    test('with operation type', () {
+      var doc =
+          parse(r'query foo ($one: [int] = 2) @foo @bar: 2 {foo, bar: baz}')
+              .parseDocument();
+      expect(doc.definitions, hasLength(1));
+      expect(doc.definitions.first,
+          const isInstanceOf<OperationDefinitionContext>());
+      var op = doc.definitions.first as OperationDefinitionContext;
+      expect(op.isMutation, isFalse);
+      expect(op.isQuery, isTrue);
+
+      expect(op.variableDefinitions.variableDefinitions, hasLength(1));
+      expect(
+          op.variableDefinitions.variableDefinitions.first,
+          isVariableDefinition('one',
+              type: isListType(isType('int'), isNullable: true),
+              defaultValue: isValue(2)));
+
+      expect(op.directives, hasLength(2));
+      expect(op.directives[0], isDirective('foo'));
+      expect(op.directives[1], isDirective('bar', valueOrVariable: equals(2)));
+
+      expect(op.selectionSet, isNotNull);
+      expect(
+          op.selectionSet,
+          isSelectionSet([
+            isField(fieldName: isFieldName('foo')),
+            isField(fieldName: isFieldName('bar', alias: 'baz'))
+          ]));
+    });
+
+    test('exceptions', () {
+      expect(
+          () => parse('query').parseOperationDefinition(), throwsSyntaxError);
+      expect(() => parse('query foo()').parseOperationDefinition(),
+          throwsSyntaxError);
+    });
+  });
+}

test/field_test.dart

@@ -109,22 +109,22 @@ class _IsField extends Matcher {
 }
 
 class _IsFieldName extends Matcher {
-  final String name, alias;
+  final String name, realName;
 
-  _IsFieldName(this.name, this.alias);
+  _IsFieldName(this.name, this.realName);
 
   @override
   Description describe(Description description) {
-    if (alias != null)
+    if (realName != null)
-      return description.add('is field with name "$name" and alias "$alias"');
+      return description.add('is field with name "$name" and alias "$realName"');
     return description.add('is field with name "$name"');
   }
 
   @override
   bool matches(item, Map matchState) {
     var fieldName = item is FieldNameContext ? item : parseFieldName(item);
-    if (alias != null)
+    if (realName != null)
-      return fieldName.alias?.name == name && fieldName.alias?.alias == alias;
+      return fieldName.alias?.alias == name && fieldName.alias?.name == realName;
     else
       return fieldName.name == name;
   }

test/variable_definition_test.dart

@@ -21,6 +21,8 @@ main() {
     expect(() => parseVariableDefinition(r'$foo'), throwsSyntaxError);
     expect(() => parseVariableDefinition(r'$foo:'), throwsSyntaxError);
     expect(() => parseVariableDefinition(r'$foo: int ='), throwsSyntaxError);
+    expect(() => parse(r'($foo: int = 2').parseVariableDefinitions(),
+        throwsSyntaxError);
   });
 }