pkg/analyzer/lib/src/test_utilities/mock_sdk.dart

// Copyright (c) 2018, 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.

import 'dart:convert';

import 'package:analyzer/file_system/file_system.dart';
import 'package:analyzer/file_system/memory_file_system.dart';
import 'package:analyzer/src/dart/analysis/experiments.dart';
import 'package:analyzer/src/dart/sdk/sdk.dart';
import 'package:analyzer/src/generated/sdk.dart';
import 'package:meta/meta.dart';

@Deprecated('Use createMockSdk() instead')
const String sdkRoot = '/sdk';

final MockSdkLibrary _LIB_ASYNC = MockSdkLibrary('async', [
  MockSdkLibraryUnit(
    'async/async.dart',
    '''
library dart.async;

import 'dart:math';

part 'stream.dart';

abstract class Future<T> {
  factory Future(FutureOr<T> computation()) {
    throw 0;
  }

  factory Future.delayed(Duration duration, [FutureOr<T> computation()?]) {
    throw 0;
  }

  factory Future.microtask(FutureOr<T> computation()) {
    throw 0;
  }

  factory Future.value([FutureOr<T>? result]) {
    throw 0;
  }

  Future<T> catchError(Function onError, {bool test(Object error)});

  Future<R> then<R>(FutureOr<R> onValue(T value), {Function? onError});

  Future<T> whenComplete(action());

  static Future<List<T>> wait<T>(Iterable<Future<T>> futures, 
    {void cleanUp(T successValue)?}) => throw 0;
}

abstract class FutureOr<T> {}

abstract class Completer<T> {
  factory Completer() {
    throw 0;
  }

  factory Completer.sync() {
    throw 0;
  }

  Future<T> get future;
  bool get isCompleted;

  void complete([FutureOr<T>? value]);
  void completeError(Object error, [StackTrace? stackTrace]);
}

abstract class Timer {
  static void run(void callback()) {}
}
''',
  ),
  MockSdkLibraryUnit(
    'async/stream.dart',
    r'''
part of dart.async;

abstract class Stream<T> {
  Stream();
  factory Stream.fromIterable(Iterable<T> data) {
    throw 0;
  }

  Future<T> get first;

  StreamSubscription<T> listen(void onData(T event)?,
      {Function? onError, void onDone()?, bool? cancelOnError});

  Stream<T> handleError(Function onError, {bool test(dynamic error)});
}

abstract class StreamIterator<T> {}

abstract class StreamSubscription<T> {
  bool get isPaused;

  Future<E> asFuture<E>([E? futureValue]);
  Future cancel();
  void onData(void handleData(T data)?);
  void onError(Function? handleError);
  void onDone(void handleDone()?);
  void pause([Future<void>? resumeSignal]);
  void resume();
}

abstract class StreamTransformer<S, T> {}
''',
  )
]);

final MockSdkLibrary _LIB_ASYNC2 = MockSdkLibrary('async2', [
  MockSdkLibraryUnit(
    'async2/async2.dart',
    '''
library dart.async2;

class Future {}
''',
  )
]);

final MockSdkLibrary _LIB_COLLECTION = MockSdkLibrary('collection', [
  MockSdkLibraryUnit(
    'collection/collection.dart',
    '''
library dart.collection;

abstract class HashMap<K, V> implements Map<K, V> {
  external factory HashMap(
      {bool Function(K, K)? equals,
      int Function(K)? hashCode,
      bool Function(dynamic)? isValidKey});

  external factory HashMap.identity();

  factory HashMap.from(Map<dynamic, dynamic> other) {
    throw 0;
  }

  factory HashMap.of(Map<K, V> other) {
    throw 0;
  }

  factory HashMap.fromIterable(Iterable iterable,
      {K Function(dynamic element)? key, V Function(dynamic element)? value}) {
    throw 0;
  }

  factory HashMap.fromIterables(Iterable<K> keys, Iterable<V> values) {
    throw 0;
  }

  factory HashMap.fromEntries(Iterable<MapEntry<K, V>> entries) {
    throw 0;
  }
}

abstract class IterableMixin<E> implements Iterable<E> { }

abstract class LinkedHashMap<K, V> implements Map<K, V> {
  external factory LinkedHashMap(
      {bool Function(K, K)? equals,
      int Function(K)? hashCode,
      bool Function(dynamic)? isValidKey});

  external factory LinkedHashMap.identity();

  factory LinkedHashMap.from(Map<dynamic, dynamic> other) {
    throw 0;
  }

  factory LinkedHashMap.of(Map<K, V> other) {
    throw 0;
  }

  factory LinkedHashMap.fromIterable(Iterable iterable,
      {K Function(dynamic element)? key, V Function(dynamic element)? value}) {
    throw 0;
  }

  factory LinkedHashMap.fromIterables(Iterable<K> keys, Iterable<V> values) {
    throw 0;
  }

  factory LinkedHashMap.fromEntries(Iterable<MapEntry<K, V>> entries) {
    throw 0;
  }
}

abstract class LinkedHashSet<E> implements Set<E> {
  external factory LinkedHashSet(
      {bool Function(E, E)? equals,
      int Function(E)? hashCode,
      bool Function(dynamic)? isValidKey});

  external factory LinkedHashSet.identity();

  factory LinkedHashSet.from(Iterable<dynamic> elements) {
    throw 0;
  }

  factory LinkedHashSet.of(Iterable<E> elements) {
    throw 0;
  }
}

abstract class ListMixin<E> implements List<E> { }

abstract class MapMixin<K, V> implements Map<K, V> { }

abstract class SetMixin<E> implements Set<E> { }
''',
  )
]);

final MockSdkLibrary _LIB_CONVERT = MockSdkLibrary(
  'convert',
  [
    MockSdkLibraryUnit(
      'convert/convert.dart',
      '''
library dart.convert;

import 'dart:async';

abstract class Converter<S, T> implements StreamTransformer {}

abstract class Encoding {}

class JsonDecoder extends Converter<String, Object> {}

const JsonCodec json = JsonCodec();

class JsonCodec {
  const JsonCodec();
  String encode(Object? value, {Object? toEncodable(dynamic object)?}) => '';
}

abstract class StringConversionSink { }

abstract class StringConversionSinkMixin implements StringConversionSink { }
''',
    )
  ],
);

final MockSdkLibrary _LIB_CORE = MockSdkLibrary(
  'core',
  [
    MockSdkLibraryUnit(
      'core/core.dart',
      '''
library dart.core;

import 'dart:async'; // ignore: unused_import

export 'dart:async' show Future, Stream;

const deprecated = const Deprecated("next release");

const override = const _Override();

const proxy = const _Proxy();

external bool identical(Object? a, Object? b);

void print(Object? object) {}

class ArgumentError extends Error {
  ArgumentError([message]);

  static T checkNotNull<T>(T argument, [String, name]) => argument;
}

// In the SDK this is an abstract class.
class BigInt implements Comparable<BigInt> {
  static BigInt parse(String source, {int radix}) => BigInt();
}

abstract class bool extends Object {
  external const factory bool.fromEnvironment(String name,
      {bool defaultValue: false});

  external const factory bool.hasEnvironment(String name);

  bool operator &(bool other);
  bool operator |(bool other);
  bool operator ^(bool other);
}

abstract class Comparable<T> {
  int compareTo(T other);
  static int compare(Comparable a, Comparable b) => a.compareTo(b);
}

typedef Comparator<T> = int Function(T a, T b);

class DateTime extends Object {
  external DateTime._now();
  DateTime.now() : this._now();
  external bool isBefore(DateTime other);
  external int get millisecondsSinceEpoch;
}

class Deprecated extends Object {
  final String expires;
  const Deprecated(this.expires);
}

class pragma {
  final String name;
  final Object? options;
  const pragma(this.name, [this.options]);
}

abstract class double extends num {
  // TODO: remove these old constants when no tests rely on them.
  static const double NAN = 0.0 / 0.0;
  static const double INFINITY = 1.0 / 0.0;
  static const double NEGATIVE_INFINITY = -INFINITY;
  static const double MIN_POSITIVE = 5e-324;
  static const double MAX_FINITE = 1.7976931348623157e+308;

  static const double nan = 0.0 / 0.0;
  static const double infinity = 1.0 / 0.0;
  static const double negativeInfinity = -infinity;
  static const double minPositive = 5e-324;
  static const double maxFinite = 1.7976931348623157e+308;

  double get sign;
  double operator %(num other);
  double operator *(num other);
  double operator +(num other);
  double operator -(num other);
  double operator -();
  double operator /(num other);
  int operator ~/(num other);

  double abs();
  int ceil();
  double ceilToDouble();
  int floor();
  double floorToDouble();
  double remainder(num other);
  int round();
  double roundToDouble();
  int truncate();
  double truncateToDouble();

  external static double parse(String source,
      [@deprecated double onError(String source)?]);

  external static double? tryParse(String source);
}

class Duration implements Comparable<Duration> {}

class Error {
  Error();
  static String safeToString(Object? object) => '';
  external StackTrace? get stackTrace;
}

class Exception {
  factory Exception([var message]) {
    throw 0;
  }
}

class FormatException implements Exception {}

class Function {}

abstract class int extends num {
  external const factory int.fromEnvironment(String name,
      {int defaultValue = 0});

  bool get isEven => false;
  bool get isNegative;
  bool get isOdd;
  int get sign;

  int operator &(int other);
  int operator -();
  int operator <<(int shiftAmount);
  int operator >>(int shiftAmount);
  int operator >>>(int shiftAmount);
  int operator ^(int other);
  int operator |(int other);
  int operator ~();

  int abs();
  int ceil();
  int gcd(int other);
  String toString();
  int truncate();

  external static int parse(String source,
      {int? radix, @deprecated int onError(String source)?});

  external static int? tryParse(String source, {int? radix});
}

abstract class Invocation {}

abstract class Iterable<E> {
  E get first;
  bool get isEmpty;
  bool get isNotEmpty;
  Iterator<E> get iterator;
  int get length;

  const Iterable();

  const factory Iterable.empty() => EmptyIterable<E>();

  bool contains(Object? element);

  Iterable<T> expand<T>(Iterable<T> f(E element));

  E firstWhere(bool test(E element), {E orElse()?});

  R fold<R>(R initialValue, R combine(R previousValue, E element));

  void forEach(void f(E element));

  E lastWhere(bool test(E element), {E orElse()?});

  Iterable<R> map<R>(R f(E e));

  E singleWhere(bool test(E element), {E orElse()?});

  List<E> toList({bool growable = true});

  Set<E> toSet();

  Iterable<E> where(bool test(E element));
  Iterable<T> whereType<T>();
}

abstract class Iterator<E> {
  E get current;
  bool moveNext();
}

class List<E> implements Iterable<E> {
  external factory List([int? length]);
  external factory List.filled(int length, E fill, {bool growable = false});
  external factory List.empty({bool growable = false});
  external factory List.from(Iterable elements, {bool growable = true});
  external factory List.of(Iterable<E> elements, {bool growable = true});
  external factory List.generate(int length, E generator(int index),
      {bool growable = true});
  external factory List.unmodifiable(Iterable elements);

  E get last => throw 0;
  E operator [](int index) => throw 0;
  void operator []=(int index, E value) {}

  void add(E value) {}
  void addAll(Iterable<E> iterable) {}
  Map<int, E> asMap() {}
  void clear() {}
  int indexOf(Object element);
  bool remove(Object? value);
  E removeLast() {}

  noSuchMethod(Invocation invocation) => null;
}

abstract class Map<K, V> {
  external factory Map();
  external factory Map.from();
  external Map.of(Map<K, V> other);
  external factory Map.unmodifiable(Map<dynamic, dynamic> other);
  external factory Map.identity();

  external factory Map.fromIterable(Iterable iterable,
      {K key(element)?, V value(element)?});

  external factory Map.fromIterables(Iterable<K> keys, Iterable<V> values);
  external factory Map.fromEntries(Iterable<MapEntry<K, V>> entries);

  Iterable<K> get keys;
  bool get isEmpty;
  bool get isNotEmpty;
  int get length => 0;
  Iterable<V> get values;

  V? operator [](Object? key);
  void operator []=(K key, V value);

  void addAll(Map<K, V> other);
  Map<RK, RV> cast<RK, RV>();
  bool containsKey(Object? key);
  void forEach(void action(K key, V value));
  V putIfAbsent(K key, V ifAbsent());
}

class Null extends Object {
  factory Null._uninstantiable() {
    throw 0;
  }
}

class MapEntry<K, V> {
  final K key;
  final V value;
  const factory MapEntry(K key, V value) = MapEntry<K, V>._;
  const MapEntry._(this.key, this.value);
}

abstract class num implements Comparable<num> {
  num operator %(num other);
  num operator *(num other);
  num operator +(num other);
  num operator -(num other);
  num operator -();
  double operator /(num other);
  bool operator <(num other);
  int operator <<(int other);
  bool operator <=(num other);
  bool operator ==(Object other);
  bool operator >(num other);
  bool operator >=(num other);
  int operator >>(int other);
  int operator ^(int other);
  int operator |(int other);
  int operator ~();
  int operator ~/(num other);

  num abs();
  num clamp(num lowerLimit, num upperLimit);
  int floor();
  num remainder(num other);
  int round();
  double toDouble();
  int toInt();
}

abstract class Match {
  int get start;
}

class Object {
  const Object();

  external int get hashCode;
  external Type get runtimeType;

  external bool operator ==(Object other);

  external String toString();
  external dynamic noSuchMethod(Invocation invocation);

  static int hash(Object? object1, Object? object2) => 0;
  static int hashAll(Iterable<Object?> objects) => 0;
  static int hashAllUnordered(Iterable<Object?> objects) => 0;
}

abstract class Enum {
  int get index;
}

abstract class _Enum extends Enum {
  String _name;
}

abstract class Pattern {
  Iterable<Match> allMatches(String string, [int start = 0]);
}

abstract class RegExp implements Pattern {
  external factory RegExp(String source, {bool unicode = false});
}

abstract class Set<E> implements Iterable<E> {
  external factory Set();
  external factory Set.identity();
  external factory Set.from(Iterable elements);
  external factory Set.of(Iterable<E> elements);

  Set<R> cast<R>();

  bool add(E value);
  void addAll(Iterable<E> elements);
  bool remove(Object? value);
  E? lookup(Object? object);
}

class StackTrace {}

abstract class String implements Comparable<String>, Pattern {
  external factory String.fromCharCodes(Iterable<int> charCodes,
      [int start = 0, int? end]);

  external factory String.fromCharCode(int charCode);

  external const factory String.fromEnvironment(String name,
      {String defaultValue = ""});

  List<int> get codeUnits;
  bool get isEmpty => false;
  bool get isNotEmpty => false;
  int get length => 0;

  bool operator ==(Object other);
  String operator [](int index);
  String operator +(String other);
  String operator *(int times);

  int codeUnitAt(int index);
  bool contains(String other, [int startIndex = 0]);
  int indexOf(Pattern pattern, [int start = 0]);
  int lastIndexOf(Pattern pattern, [int? start]);
  bool startsWith(Pattern pattern, [int index = 0]);
  List<String> split(Pattern pattern);
  String splitMapJoin(Pattern pattern,
      {String Function(Match)? onMatch, String Function(String)? onNonMatch});
  String substring(int startIndex, [int? endIndex]);
  String toLowerCase();
  String toUpperCase();
}

class Symbol {
  const factory Symbol(String name) = _SymbolImpl;
}

class Type {}

class UnsupportedError {
  UnsupportedError(String message);
}

class Uri {
  static List<int> parseIPv6Address(String host, [int start = 0, int end]) {
    return null;
  }
}

class _Override {
  const _Override();
}

class _Proxy {
  const _Proxy();
}

class _SymbolImpl {
  const _SymbolImpl(String name);
}
''',
    )
  ],
);

final MockSdkLibrary _LIB_FFI = MockSdkLibrary('ffi', [
  MockSdkLibraryUnit(
    'ffi/ffi.dart',
    '''
library dart.ffi;

class NativeType {
  const NativeType();
}

class Handle extends NativeType {}

class Void extends NativeType {}

class Int8 extends NativeType {
  const Int8();
}

class Uint8 extends NativeType {
  const Uint8();
}

class Int16 extends NativeType {
  const Int16();
}

class Uint16 extends NativeType {
  const Uint16();
}

class Int32 extends NativeType {
  const Int32();
}

class Uint32 extends NativeType {
  const Uint32();
}

class Int64 extends NativeType {
  const Int64();
}

class Uint64 extends NativeType {
  const Uint64();
}

class Float extends NativeType {
  const Float();
}

class Double extends NativeType {
  const Double();
}

class Pointer<T extends NativeType> extends NativeType {
  external factory Pointer.fromAddress(int ptr);

  static Pointer<NativeFunction<T>> fromFunction<T extends Function>(
      @DartRepresentationOf("T") Function f,
      [Object exceptionalReturn]) {}
}

final Pointer<Never> nullptr = Pointer.fromAddress(0);

extension NativeFunctionPointer<NF extends Function>
    on Pointer<NativeFunction<NF>> {
  external DF asFunction<DF extends Function>({bool isLeaf:false});
}

class _Compound extends NativeType {}

class Struct extends _Compound {}

class Union extends _Compound {}

class Packed {
  final int memberAlignment;

  const Packed(this.memberAlignment);
}

abstract class DynamicLibrary {
  external factory DynamicLibrary.open(String name);
}

extension DynamicLibraryExtension on DynamicLibrary {
  external F lookupFunction<T extends Function, F extends Function>(
      String symbolName, {bool isLeaf:false});
}

abstract class NativeFunction<T extends Function> extends NativeType {}

class DartRepresentationOf {
  const DartRepresentationOf(String nativeType);
}

class Array<T extends NativeType> extends NativeType {
  const factory Array(int dimension1,
      [int dimension2,
      int dimension3,
      int dimension4,
      int dimension5]) = _ArraySize<T>;

  const factory Array.multi(List<int> dimensions) = _ArraySize<T>.multi;
}

class _ArraySize<T extends NativeType> implements Array<T> {
  final int? dimension1;
  final int? dimension2;
  final int? dimension3;
  final int? dimension4;
  final int? dimension5;

  final List<int>? dimensions;

  const _ArraySize(this.dimension1,
      [this.dimension2, this.dimension3, this.dimension4, this.dimension5])
      : dimensions = null;

  const _ArraySize.multi(this.dimensions)
      : dimension1 = null,
        dimension2 = null,
        dimension3 = null,
        dimension4 = null,
        dimension5 = null;
}

extension StructPointer<T extends Struct> on Pointer<T> {
  external T get ref;

  external T operator [](int index);
}

class FfiNative<T> {
  final String nativeName;
  final bool isLeaf;
  const FfiNative(this.nativeName, {this.isLeaf: false});
}
''',
  )
]);

final MockSdkLibrary _LIB_HTML_DART2JS = MockSdkLibrary(
  'html',
  [
    MockSdkLibraryUnit(
      'html/dart2js/html_dart2js.dart',
      '''
library dart.dom.html;

import 'dart:async';

class Event {}

class MouseEvent extends Event {}

class FocusEvent extends Event {}

class KeyEvent extends Event {}

abstract class ElementStream<T extends Event> implements Stream<T> {}

abstract class Element {
  factory Element.html(String html,
          {NodeValidator validator, NodeTreeSanitizer treeSanitizer}) =>
      new HtmlElement();

  /// Stream of `cut` events handled by this [Element].
  ElementStream<Event> get onCut => throw 0;

  String get id => throw 0;

  set id(String value) => throw 0;

  DocumentFragment createFragment(String html,
          {NodeValidator validator, NodeTreeSanitizer treeSanitizer}) => null;

  void setInnerHtml(String html,
          {NodeValidator validator, NodeTreeSanitizer treeSanitizer}) {}
}

class HtmlElement extends Element {
  int tabIndex;
  ElementStream<Event> get onChange => throw 0;
  ElementStream<MouseEvent> get onClick => throw 0;
  ElementStream<KeyEvent> get onKeyUp => throw 0;
  ElementStream<KeyEvent> get onKeyDown => throw 0;

  bool get hidden => throw 0;
  set hidden(bool value) {}

  void set className(String s) {}
  void set readOnly(bool b) {}
  void set tabIndex(int i) {}

  String _innerHtml;
  String get innerHtml {
    throw 'not the real implementation';
  }

  set innerHtml(String value) {
    // stuff
  }
}

class AnchorElement extends HtmlElement {
  factory AnchorElement({String href}) {
    AnchorElement e = JS('returns:AnchorElement;creates:AnchorElement;new:true',
        '#.createElement(#)', document, "a");
    if (href != null) e.href = href;
    return e;
  }

  String href;
  String _privateField;
}

class BodyElement extends HtmlElement {
  factory BodyElement() => document.createElement("body");

  ElementStream<Event> get onUnload => throw 0;
}

class ButtonElement extends HtmlElement {
  factory ButtonElement._() {
    throw new UnsupportedError("Not supported");
  }
  factory ButtonElement() => document.createElement("button");

  bool autofocus;
}

class EmbedElement extends HtmlEment {
  String src;
}

class HeadingElement extends HtmlElement {
  factory HeadingElement._() {
    throw new UnsupportedError("Not supported");
  }
  factory HeadingElement.h1() => document.createElement("h1");
  factory HeadingElement.h2() => document.createElement("h2");
  factory HeadingElement.h3() => document.createElement("h3");
}

class ImageElement extends HtmlEment {
  String src;
}

class InputElement extends HtmlElement {
  factory InputElement._() {
    throw new UnsupportedError("Not supported");
  }
  factory InputElement() => document.createElement("input");

  String value;
  String validationMessage;
}

class IFrameElement extends HtmlElement {
  factory IFrameElement._() {
    throw new UnsupportedError("Not supported");
  }
  factory IFrameElement() => JS(
      'returns:IFrameElement;creates:IFrameElement;new:true',
      '#.createElement(#)',
      document,
      "iframe");

  String src;
  set srcdoc(String? value) native;
}

class OptionElement extends HtmlElement {
  factory OptionElement(
      {String data: '', String value: '', bool selected: false}) {}

  factory OptionElement._(
      [String data, String value, bool defaultSelected, bool selected]) {}
}

class ScriptElement extends HtmlElement {
  String src;
  String type;
}

class TableSectionElement extends HtmlElement {
  List<TableRowElement> get rows => throw 0;

  TableRowElement addRow() {}

  TableRowElement insertRow(int index) => throw 0;

  factory TableSectionElement._() {
    throw new UnsupportedError("Not supported");
  }

  @Deprecated("Internal Use Only")
  external static Type get instanceRuntimeType;

  @Deprecated("Internal Use Only")
  TableSectionElement.internal_() : super.internal_();
}

class TemplateElement extends HtmlElement {
  factory TemplateElement._() {
    throw new UnsupportedError("Not supported");
  }
  factory TemplateElement() => document.createElement("template");
}

class AudioElement extends MediaElement {
  factory AudioElement._([String src]) {
    if (src != null) {
      return AudioElement._create_1(src);
    }
    return AudioElement._create_2();
  }

  static AudioElement _create_1(src) => JS('AudioElement', 'new Audio(#)', src);
  static AudioElement _create_2() => JS('AudioElement', 'new Audio()');
  AudioElement.created() : super.created();

  factory AudioElement([String src]) => new AudioElement._(src);
}

class MediaElement extends Element {}

class WindowBase {}

class Window extends WindowBase {
  WindowBase open(String url, String name, [String options]) => null;
}

class NodeValidator {}

class NodeTreeSanitizer {}

class DocumentFragment {
  DocumentFragment.html(String html,
          {NodeValidator validator, NodeTreeSanitizer treeSanitizer}) {}
}

dynamic JS(a, b, c, d) {}

class File {}
''',
    )
  ],
);

final MockSdkLibrary _LIB_INTERCEPTORS = MockSdkLibrary(
  '_interceptors',
  [
    MockSdkLibraryUnit(
      '_internal/js_runtime/lib/interceptors.dart',
      '''
library dart._interceptors;
''',
    )
  ],
);

final MockSdkLibrary _LIB_INTERNAL = MockSdkLibrary(
  '_internal',
  [
    MockSdkLibraryUnit(
      '_internal/internal.dart',
      '''
library dart._internal;

class Symbol {}

class EmptyIterable<E> implements Iterable<E> {
  const EmptyIterable();
}

class ExternalName {
  final String name;
  const ExternalName(this.name);
}
''',
    )
  ],
  categories: '',
);

final MockSdkLibrary _LIB_IO = MockSdkLibrary(
  'io',
  [
    MockSdkLibraryUnit(
      'io/io.dart',
      '''
library dart.io;

import 'dart:convert';

Never exit(int code) => throw code;

abstract class Directory implements FileSystemEntity {
  factory Directory(String path) {
    throw 0;
  }

  Future<bool> exists() async => true;
  bool existsSync() => true;

  Future<FileStat> stat() async => throw 0;
  FileStat statSync() => throw 0;
}

abstract class File implements FileSystemEntity {
  factory File(String path) {
    throw 0;
  }

  Future<DateTime> lastModified();
  DateTime lastModifiedSync();

  Future<bool> exists();
  bool existsSync();

  Future<FileStat> stat();
  FileStat statSync();
}

abstract class FileSystemEntity {
  static Future<bool> isDirectory(String path) async => true;
  static bool isDirectorySync(String path) => true;

  static Future<bool> isFile(String path) async => true;
  static bool isFileSync(String path) => true;

  static Future<bool> isLink(String path) async => true;
  static bool isLinkSync(String path) => true;

  static Future<FileSystemEntityType> type(String path,
          {bool followLinks: true}) =>
      throw 0;
  static FileSystemEntityType typeSync(String path, {bool followLinks: true}) =>
      throw 0;
}

enum ProcessStartMode {
  normal,
}

abstract class Process {
  external static Future<Process> start(
    String executable,
    List<String> arguments, {
    String? workingDirectory,
    Map<String, String>? environment,
    bool includeParentEnvironment: true,
    bool runInShell: false,
    ProcessStartMode mode: ProcessStartMode.normal,
  });

  external static Future<ProcessResult> run(
    String executable,
    List<String> arguments, {
    String? workingDirectory,
    Map<String, String>? environment,
    bool includeParentEnvironment: true,
    bool runInShell: false,
    Encoding? stdoutEncoding,
    Encoding? stderrEncoding,
  });
}
''',
    )
  ],
);

final MockSdkLibrary _LIB_ISOLATE = MockSdkLibrary('isolate', [
  MockSdkLibraryUnit(
    'isolate.dart',
    '''
library dart.isolate;

abstract class SendPort {}

class Isolate {
  external static Future<Isolate> spawnUri(
    Uri uri,
    List<String> args,
    var message, {
    bool paused = false,
    SendPort? onExit,
    SendPort? onError,
    bool errorsAreFatal = true,
    bool? checked,
    Map<String, String>? environment,
    @deprecated Uri? packageRoot,
    Uri? packageConfig,
    bool automaticPackageResolution = false,
    String? debugName,
  });
}
''',
  )
]);

final MockSdkLibrary _LIB_MATH = MockSdkLibrary(
  'math',
  [
    MockSdkLibraryUnit(
      'math/math.dart',
      '''
library dart.math;

const double e = 2.718281828459045;
const double pi = 3.1415926535897932;
const double ln10 = 2.302585092994046;

T min<T extends num>(T a, T b) => throw 0;
T max<T extends num>(T a, T b) => throw 0;

external double cos(num radians);
external double sin(num radians);
external double sqrt(num radians);
external double tan(num radians);

class Random {
  bool nextBool() => true;
  double nextDouble() => 2.0;
  int nextInt() => 1;
}

class Point<T extends num> {}
''',
    )
  ],
);

final List<MockSdkLibrary> _LIBRARIES = [
  _LIB_CORE,
  _LIB_ASYNC,
  _LIB_ASYNC2,
  _LIB_COLLECTION,
  _LIB_CONVERT,
  _LIB_FFI,
  _LIB_IO,
  _LIB_ISOLATE,
  _LIB_MATH,
  _LIB_HTML_DART2JS,
  _LIB_INTERCEPTORS,
  _LIB_INTERNAL,
];

/// Create a reduced approximation of Dart SDK in the [path].
///
/// It has enough libraries to run analyzer and analysis server tests,
/// but some libraries, classes, and methods are missing.
void createMockSdk({
  required MemoryResourceProvider resourceProvider,
  required Folder root,
  @internal List<MockSdkLibrary> additionalLibraries = const [],
}) {
  var lib = root.getChildAssumingFolder('lib');
  var libInternal = lib.getChildAssumingFolder('_internal');

  var currentVersion = ExperimentStatus.currentVersion;
  var currentVersionStr = '${currentVersion.major}.${currentVersion.minor}.0';
  root.getChildAssumingFile('version').writeAsStringSync(currentVersionStr);

  var librariesBuffer = StringBuffer();
  librariesBuffer.writeln(
    'const Map<String, LibraryInfo> libraries = const {',
  );

  for (var library in [..._LIBRARIES, ...additionalLibraries]) {
    for (var unit in library.units) {
      var file = lib.getChildAssumingFile(unit.path);
      file.writeAsStringSync(unit.content);
    }
    librariesBuffer.writeln(
      '  "${library.name}": const LibraryInfo("${library.path}", '
      'categories: "${library.categories}"),',
    );
  }

  librariesBuffer.writeln('};');
  libInternal
      .getChildAssumingFile('sdk_library_metadata/lib/libraries.dart')
      .writeAsStringSync('$librariesBuffer');

  libInternal
      .getChildAssumingFile('allowed_experiments.json')
      .writeAsStringSync(
        json.encode({
          'version': 1,
          'experimentSets': {
            'sdkExperiments': <String>[],
            'nullSafety': ['non-nullable']
          },
          'sdk': {
            'default': {'experimentSet': 'sdkExperiments'},
          },
          'packages': <String, Object>{},
        }),
      );
}

@Deprecated('Use createMockSdk() and FolderBasedDartSdk instead.')
class MockSdk extends FolderBasedDartSdk {
  /// Optional [additionalLibraries] should have unique URIs, and paths in
  /// their units are relative (will be put into `sdkRoot/lib`).
  factory MockSdk({
    required MemoryResourceProvider resourceProvider,
    List<MockSdkLibrary> additionalLibraries = const [],
  }) {
    var sdkDirectory = resourceProvider.getFolder(
      resourceProvider.convertPath(sdkRoot),
    );
    createMockSdk(
      resourceProvider: resourceProvider,
      root: sdkDirectory,
      additionalLibraries: additionalLibraries,
    );
    return MockSdk._(resourceProvider, sdkDirectory);
  }

  /// Initialize a newly created SDK to represent the Dart SDK installed in the
  /// [sdkDirectory].
  MockSdk._(ResourceProvider resourceProvider, Folder sdkDirectory)
      : super(resourceProvider, sdkDirectory);

  @override
  MemoryResourceProvider get resourceProvider {
    return super.resourceProvider as MemoryResourceProvider;
  }

  @override
  List<SdkLibraryImpl> get sdkLibraries {
    return super.sdkLibraries.map((library) {
      var pathContext = resourceProvider.pathContext;
      var path = library.path;
      if (pathContext.isAbsolute(path)) {
        return library;
      }
      return SdkLibraryImpl(library.shortName)
        ..path = pathContext.join(directory.path, 'lib', path)
        ..category = library.category
        ..documented = library.isDocumented;
    }).toList();
  }
}

class MockSdkLibrary implements SdkLibrary {
  final String name;
  final String categories;
  final List<MockSdkLibraryUnit> units;

  MockSdkLibrary(this.name, this.units, {this.categories = 'Shared'});

  @override
  String get category => throw UnimplementedError();

  @override
  bool get isDart2JsLibrary => throw UnimplementedError();

  @override
  bool get isDocumented => throw UnimplementedError();

  @override
  bool get isImplementation => throw UnimplementedError();

  @override
  bool get isInternal => shortName.startsWith('dart:_');

  @override
  bool get isShared => throw UnimplementedError();

  @override
  bool get isVmLibrary => throw UnimplementedError();

  @override
  String get path => units[0].path;

  @override
  String get shortName => 'dart:$name';
}

class MockSdkLibraryUnit {
  final String path;
  final String content;

  MockSdkLibraryUnit(this.path, this.content);
}