Create associated packages for the dart:collection and dart:async libs.

pkg/collection_helpers/test/algorithms_test.dart

-// Copyright (c) 2013, 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.
-
-/// Tests algorithm utilities.
-
-import "package:collection_helpers/all.dart";
-import "package:unittest/unittest.dart";
-import 'dart:math';
-
-void main() {
-  void testShuffle(List list) {
-    List copy = list.toList();
-    shuffle(list);
-    expect(new UnorderedIterableEquality().equals(list, copy), isTrue);
-  }
-
-  test("Shuffle 0", () {
-    testShuffle([]);
-  });
-  test("Shuffle 1", () {
-    testShuffle([1]);
-  });
-  test("Shuffle 3", () {
-    testShuffle([1, 2, 3]);
-  });
-  test("Shuffle 10", () {
-    testShuffle([1, 2, 3, 4, 5, 1, 3, 5, 7, 9]);
-  });
-  test("Shuffle shuffles", () {
-    List l = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
-    List c = l.toList();
-    int count = 0;
-    do {
-      shuffle(l);
-      if (!const ListEquality().equals(c, l)) return;
-      // Odds of not changing the order should be one in ~ 16! ~= 2e+13.
-      // Repeat this 10 times, and the odds of accidentally shuffling to the
-      // same result every time is disappearingly tiny.
-      count++;
-      // If this happens even once, it's ok to report it.
-      print("Failed shuffle $count times");
-      if (count == 10) fail("Shuffle didn't change order.");
-    } while (true);
-  });
-  test("Shuffle sublist", (){
-    List l = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
-    List c = l.toList();
-    shuffle(l, 4, 12);
-    expect(const IterableEquality().equals(l.getRange(0, 4),
-                                           c.getRange(0, 4)), isTrue);
-    expect(const IterableEquality().equals(l.getRange(12, 16),
-                                           c.getRange(12, 16)), isTrue);
-    expect(const UnorderedIterableEquality().equals(l.getRange(4, 12),
-                                                    c.getRange(4, 12)),
-           isTrue);
-
-  });
-
-  test("binsearch0", () {
-    expect(binarySearch([], 2), equals(-1));
-  });
-
-  test("binsearch1", () {
-    expect(binarySearch([5], 2), equals(-1));
-    expect(binarySearch([5], 5), equals(0));
-    expect(binarySearch([5], 7), equals(-1));
-  });
-
-  test("binsearch3", () {
-    expect(binarySearch([0, 5, 10], -1), equals(-1));
-    expect(binarySearch([0, 5, 10], 0), equals(0));
-    expect(binarySearch([0, 5, 10], 2), equals(-1));
-    expect(binarySearch([0, 5, 10], 5), equals(1));
-    expect(binarySearch([0, 5, 10], 7), equals(-1));
-    expect(binarySearch([0, 5, 10], 10), equals(2));
-    expect(binarySearch([0, 5, 10], 12), equals(-1));
-  });
-
-  test("binsearchCompare0", () {
-    expect(binarySearch([], new C(2), compare: compareC), equals(-1));
-  });
-
-  test("binsearchCompare1", () {
-    var l1 = [new C(5)];
-    expect(binarySearch(l1, new C(2), compare: compareC), equals(-1));
-    expect(binarySearch(l1, new C(5), compare: compareC), equals(0));
-    expect(binarySearch(l1, new C(7), compare: compareC), equals(-1));
-  });
-
-  test("binsearchCompare3", () {
-    var l3 = [new C(0), new C(5), new C(10)];
-    expect(binarySearch(l3, new C(-1), compare: compareC), equals(-1));
-    expect(binarySearch(l3, new C(0), compare: compareC), equals(0));
-    expect(binarySearch(l3, new C(2), compare: compareC), equals(-1));
-    expect(binarySearch(l3, new C(5), compare: compareC), equals(1));
-    expect(binarySearch(l3, new C(7), compare: compareC), equals(-1));
-    expect(binarySearch(l3, new C(10), compare: compareC), equals(2));
-    expect(binarySearch(l3, new C(12), compare: compareC), equals(-1));
-  });
-
-  test("insertionSortRandom", () {
-    Random random = new Random();
-    for (int i = 0; i < 25; i++) {
-      List list = new List(i);
-      for (int j = 0; j < i; j++) {
-        list[j] = random.nextInt(25);  // Expect some equal elements.
-      }
-      insertionSort(list);
-      for (int j = 1; j < i; j++) {
-        expect(list[j - 1], lessThanOrEqualTo(list[j]));
-      }
-    }
-  });
-
-  test("insertionSortSubRanges", () {
-    List l = [6, 5, 4, 3, 2, 1];
-    insertionSort(l, start: 2, end: 4);
-    expect(l, equals([6, 5, 3, 4, 2, 1]));
-    insertionSort(l, start: 1, end: 1);
-    expect(l, equals([6, 5, 3, 4, 2, 1]));
-    insertionSort(l, start: 4, end: 6);
-    expect(l, equals([6, 5, 3, 4, 1, 2]));
-    insertionSort(l, start: 0, end: 2);
-    expect(l, equals([5, 6, 3, 4, 1, 2]));
-    insertionSort(l, start: 0, end: 6);
-    expect(l, equals([1, 2, 3, 4, 5, 6]));
-  });
-
-  test("insertionSortSpecialCases", () {
-    List l = [6, 6, 6, 6, 6, 6];
-    insertionSort(l);
-    expect(l, equals([6, 6, 6, 6, 6, 6]));
-
-    l = [6, 6, 3, 3, 0, 0];
-    insertionSort(l);
-    expect(l, equals([0, 0, 3, 3, 6, 6]));
-  });
-
-  test("MergeSortRandom", () {
-    Random random = new Random();
-    for (int i = 0; i < 250; i += 1) {
-      List list = new List(i);
-      for (int j = 0; j < i; j++) {
-        list[j] = random.nextInt(i);  // Expect some equal elements.
-      }
-      mergeSort(list);
-      for (int j = 1; j < i; j++) {
-        expect(list[j - 1], lessThanOrEqualTo(list[j]));
-      }
-    }
-  });
-
-  test("MergeSortPreservesOrder", () {
-    Random random = new Random();
-    // Small case where only insertion call is called,
-    // larger case where the internal moving insertion sort is used
-    // larger cases with multiple splittings, numbers just around a power of 2.
-    for (int size in [8, 50, 511, 512, 513]) {
-      List list = new List(size);
-      // Class OC compares using id.
-      // With size elements with id's in the range 0..size/4, a number of
-      // collisions are guaranteed. These should be sorted so that the "order"
-      // part of the objects are still in order.
-      for (int i = 0; i < size; i++) {
-        list[i] = new OC(random.nextInt(size >> 2), i);
-      }
-      mergeSort(list);
-      OC prev = list[0];
-      for (int i = 1; i < size; i++) {
-        OC next = list[i];
-        expect(prev.id, lessThanOrEqualTo(next.id));
-        if (next.id == prev.id) {
-          expect(prev.order, lessThanOrEqualTo(next.order));
-        }
-        prev = next;
-      }
-      // Reverse compare on part of list.
-      List copy = list.toList();
-      int min = size >> 2;
-      int max = size - min;
-      mergeSort(list, start: min, end: max, compare: (a, b) => b.compareTo(a));
-      prev = list[min];
-      for (int i = min + 1; i < max; i++) {
-        OC next = list[i];
-        expect(prev.id, greaterThanOrEqualTo(next.id));
-        if (next.id == prev.id) {
-          expect(prev.order, lessThanOrEqualTo(next.order));
-        }
-        prev = next;
-      }
-      // Equals on OC objects is identity, so this means the parts before min,
-      // and the parts after max, didn't change at all.
-      expect(list.sublist(0, min), equals(copy.sublist(0, min)));
-      expect(list.sublist(max), equals(copy.sublist(max)));
-    }
-  });
-
-  test("MergeSortSpecialCases", () {
-    for (int size in [511, 512, 513]) {
-      // All equal.
-      List list = new List(size);
-      for (int i = 0; i < size; i++) {
-        list[i] = new OC(0, i);
-      }
-      mergeSort(list);
-      for (int i = 0; i < size; i++) {
-        expect(list[i].order, equals(i));
-      }
-      // All but one equal, first.
-      list[0] = new OC(1, 0);
-      for (int i = 1; i < size; i++) {
-        list[i] = new OC(0, i);
-      }
-      mergeSort(list);
-      for (int i = 0; i < size - 1; i++) {
-        expect(list[i].order, equals(i + 1));
-      }
-      expect(list[size - 1].order, equals(0));
-
-      // All but one equal, last.
-      for (int i = 0; i < size - 1; i++) {
-        list[i] = new OC(0, i);
-      }
-      list[size - 1] = new OC(-1, size - 1);
-      mergeSort(list);
-      expect(list[0].order, equals(size - 1));
-      for (int i = 1; i < size; i++) {
-        expect(list[i].order, equals(i - 1));
-      }
-
-      // Reversed.
-      for (int i = 0; i < size; i++) {
-        list[i] = new OC(size - 1 - i, i);
-      }
-      mergeSort(list);
-      for (int i = 0; i < size; i++) {
-        expect(list[i].id, equals(i));
-        expect(list[i].order, equals(size - 1 - i));
-      }
-    }
-  });
-
-  test("Reverse", () {
-    List l = [6, 5, 4, 3, 2, 1];
-    reverse(l, 2, 4);
-    expect(l, equals([6, 5, 3, 4, 2, 1]));
-    reverse(l, 1, 1);
-    expect(l, equals([6, 5, 3, 4, 2, 1]));
-    reverse(l, 4, 6);
-    expect(l, equals([6, 5, 3, 4, 1, 2]));
-    reverse(l, 0, 2);
-    expect(l, equals([5, 6, 3, 4, 1, 2]));
-    reverse(l, 0, 6);
-    expect(l, equals([2, 1, 4, 3, 6, 5]));
-  });
-}
-
-class C {
-  final int id;
-  C(this.id);
-}
-int compareC(C one, C other) => one.id - other.id;
-
-class OC implements Comparable<OC> {
-  final int id;
-  final int order;
-  OC(this.id, this.order);
-  int compareTo(OC other) => id - other.id;
-  String toString() => "OC[$id,$order]";
-}