sdk/pkg/dev_compiler/tool/input_sdk/private/interceptors.dart

// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

library dart._interceptors;

import 'dart:collection';
import 'dart:_internal' hide Symbol;
import 'dart:_js_helper';
import 'dart:_foreign_helper' show JS, JSExportName;
import 'dart:math' show Random;
import 'dart:_runtime' as dart;

part 'js_array.dart';
part 'js_number.dart';
part 'js_string.dart';

// TODO(jmesserly): remove, this doesn't do anything for us.
abstract class Interceptor {
  const Interceptor();

  // Use native JS toString method instead of standard Dart Object.toString.
  String toString() => JS('String', '#.toString()', this);
}

// TODO(jmesserly): remove
getInterceptor(obj) => obj;

/**
 * The interceptor class for [bool].
 */
@JsPeerInterface(name: 'Boolean')
class JSBool extends Interceptor implements bool {
  const JSBool();

  // Note: if you change this, also change the function [S].
  @notNull
  String toString() => JS('String', r'String(#)', this);

  // The values here are SMIs, co-prime and differ about half of the bit
  // positions, including the low bit, so they are different mod 2^k.
  @notNull
  int get hashCode => this ? (2 * 3 * 23 * 3761) : (269 * 811);

  Type get runtimeType => bool;
}

/**
 * The supertype for JSString and JSArray. Used by the backend as to
 * have a type mask that contains the objects that we can use the
 * native JS [] operator and length on.
 */
abstract class JSIndexable<E> {
  int get length;
  E operator [](int index);
}

/**
 * The interface implemented by JavaScript objects.  These are methods in
 * addition to the regular Dart Object methods like [Object.hashCode].
 *
 * This is the type that should be exported by a JavaScript interop library.
 */
abstract class JSObject {}

/**
 * Interceptor base class for JavaScript objects not recognized as some more
 * specific native type.
 */
abstract class JavaScriptObject extends Interceptor implements JSObject {
  const JavaScriptObject();

  // It would be impolite to stash a property on the object.
  int get hashCode => 0;

  Type get runtimeType => JSObject;
}

/**
 * Interceptor for plain JavaScript objects created as JavaScript object
 * literals or `new Object()`.
 */
class PlainJavaScriptObject extends JavaScriptObject {
  const PlainJavaScriptObject();
}

/**
 * Interceptor for unclassified JavaScript objects, typically objects with a
 * non-trivial prototype chain.
 *
 * This class also serves as a fallback for unknown JavaScript exceptions.
 */
class UnknownJavaScriptObject extends JavaScriptObject {
  const UnknownJavaScriptObject();

  String toString() => JS('String', 'String(#)', this);
}

class NativeError extends Interceptor {
  String dartStack() => JS('String', '#.stack', this);
}

// Note that this needs to be in interceptors.dart in order for
// it to be picked up as an extension type.
@JsPeerInterface(name: 'TypeError')
class NullError extends NativeError implements NoSuchMethodError {
  static RegExp _nullError =
      new RegExp(r"^Cannot read property '(.+)' of null$");
  static RegExp _extensionName = new RegExp(r"^Symbol\(dartx\.(.+)\)$");
  static RegExp _privateName = new RegExp(r"^Symbol\((_.+)\)$");

  String _fieldName() {
    var message = JS('String', '#.message', this);
    var match = _nullError.firstMatch(message);
    if (match == null) return null;
    var name = match[1];
    match = _extensionName.firstMatch(name) ?? _privateName.firstMatch(name);
    return match != null ? match[1] : name;
  }

  String dartStack() {
    var stack = super.dartStack();
    // Strip TypeError from first line.
    stack = toString() + '\n' + stack.split('\n').sublist(1).join('\n');
    return stack;
  }

  StackTrace get stackTrace => getTraceFromException(this);

  String toString() {
    // TODO(vsm): Distinguish between null reference errors and other
    // TypeErrors.  We should not get non-null TypeErrors from DDC code,
    // but we may from native JavaScript.
    var name = _fieldName();
    if (name == null) {
      // Not a Null NSM error: fallback to JS.
      return JS('String', '#.toString()', this);
    }
    return "NullError: invalid member on null: '$name'";
  }
}

@JsPeerInterface(name: 'Function')
class JSFunction extends Interceptor {
  toString() {
    // If the function is a Type object, we should just display the type name.
    //
    // Regular Dart code should typically get wrapped type objects instead of
    // raw type (aka JS constructor) objects, however raw type objects can be
    // exposed to Dart code via JS interop or debugging tools.
    if (dart.isType(this)) return dart.typeName(this);

    return JS('String', r'"Closure: " + # + " from: " + #',
        dart.typeName(dart.getReifiedType(this)), this);
  }

  // TODO(jmesserly): remove these once we canonicalize tearoffs.
  operator ==(other) {
    if (other == null) return false;
    var boundObj = JS<Object>('', '#._boundObject', this);
    if (boundObj == null) return JS('bool', '# === #', this, other);
    return JS(
        'bool',
        '# === #._boundObject && #._boundMethod === #._boundMethod',
        boundObj,
        other,
        this,
        other);
  }

  get hashCode {
    var boundObj = JS<Object>('', '#._boundObject', this);
    if (boundObj == null) return identityHashCode(this);

    var boundMethod = JS<Object>('!', '#._boundMethod', this);
    int hash = (17 * 31 + boundObj.hashCode) & 0x1fffffff;
    return (hash * 31 + identityHashCode(boundMethod)) & 0x1fffffff;
  }

  get runtimeType => dart.wrapType(dart.getReifiedType(this));
}

/// A class used for implementing `null` tear-offs.
class JSNull {
  toString() => 'null';
  noSuchMethod(Invocation i) => dart.defaultNoSuchMethod(null, i);
}

final Object jsNull = new JSNull();

// Note that this needs to be in interceptors.dart in order for
// it to be picked up as an extension type.
@JsPeerInterface(name: 'RangeError')
class JSRangeError extends Interceptor implements ArgumentError {
  StackTrace get stackTrace => getTraceFromException(this);

  get invalidValue => null;
  get name => null;
  get message => JS('String', '#.message', this);

  String toString() => "Invalid argument: $message";
}

// Obsolete in dart dev compiler. Added only so that the same version of
// dart:html can be used in dart2js an dev compiler.
// Warning: calls to these methods need to be removed before custom elements
// and cross-frame dom objects behave correctly in ddc.
// See https://github.com/dart-lang/sdk/issues/28326
findInterceptorConstructorForType(Type type) {}
findConstructorForNativeSubclassType(Type type, String name) {}
getNativeInterceptor(object) {}
setDispatchProperty(object, value) {}