Fix dart:collection analysis errors in NNBD fork

Change-Id: Id4a5e5b100ca1c429070263555ab730622644d19
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/127161
Reviewed-by: Leaf Petersen <leafp@google.com>
Commit-Queue: Nicholas Shahan <nshahan@google.com>

sdk_nnbd/lib/collection/hash_map.dart

@@ -83,9 +83,9 @@ abstract class HashMap<K, V> implements Map<K, V> {
   /// If you supply one of [equals] and [hashCode],
   /// you should generally also to supply the other.
   external factory HashMap(
-      {bool Function(K key1, K key2)? equals,
-      int Function(K key)? hashCode,
-      bool Function(dynamic potentialKey)? isValidKey});
+      {bool Function(K, K)? equals,
+      int Function(K)? hashCode,
+      bool Function(dynamic)? isValidKey});
 
   /// Creates an unordered identity-based map.
   ///

sdk_nnbd/lib/collection/hash_set.dart

@@ -64,9 +64,9 @@ abstract class HashSet<E> implements Set<E> {
   /// and the `isValidKey` defaults to accepting all keys.
   /// Such a map can be created directly using [HashSet.identity].
   external factory HashSet(
-      {bool Function(E e1, E e2)? equals,
-      int Function(E e)? hashCode,
-      bool Function(dynamic potentialKey)? isValidKey});
+      {bool Function(E, E)? equals,
+      int Function(E)? hashCode,
+      bool Function(dynamic)? isValidKey});
 
   /// Creates an unordered identity-based set.
   ///

sdk_nnbd/lib/collection/linked_hash_map.dart

@@ -67,9 +67,9 @@ abstract class LinkedHashMap<K, V> implements Map<K, V> {
   /// If you supply one of [equals] and [hashCode],
   /// you should generally also to supply the other.
   external factory LinkedHashMap(
-      {bool Function(K key1, K key2)? equals,
-      int Function(K key)? hashCode,
-      bool Function(dynamic potentialKey)? isValidKey});
+      {bool Function(K, K)? equals,
+      int Function(K)? hashCode,
+      bool Function(dynamic)? isValidKey});
 
   /// Creates an insertion-ordered identity-based map.
   ///

sdk_nnbd/lib/collection/linked_hash_set.dart

@@ -71,9 +71,9 @@ abstract class LinkedHashSet<E> implements Set<E> {
   /// and the `isValidKey` defaults to accepting all keys.
   /// Such a map can be created directly using [LinkedHashSet.identity].
   external factory LinkedHashSet(
-      {bool Function(E e1, E e2)? equals,
-      int Function(E e)? hashCode,
-      bool Function(dynamic potentialKey)? isValidKey});
+      {bool Function(E, E)? equals,
+      int Function(E)? hashCode,
+      bool Function(dynamic)? isValidKey});
 
   /// Creates an insertion-ordered identity-based set.
   ///

sdk_nnbd/lib/collection/linked_list.dart

@@ -143,7 +143,7 @@ class LinkedList<E extends LinkedListEntry<E>> extends Iterable<E> {
       return;
     }
     E predecessor = entry!._previous!;
-    E successor = entry!;
+    E successor = entry;
     newEntry._previous = predecessor;
     newEntry._next = successor;
     predecessor._next = newEntry;

sdk_nnbd/lib/collection/maps.dart

@@ -126,7 +126,7 @@ abstract class MapMixin<K, V> implements Map<K, V> {
 
   void addAll(Map<K, V> other) {
     for (K key in other.keys) {
-      this[key] = other[key];
+      this[key] = other[key] as V;
     }
   }
 
@@ -229,9 +229,9 @@ class _MapBaseValueIterable<K, V> extends EfficientLengthIterable<V> {
   int get length => _map.length;
   bool get isEmpty => _map.isEmpty;
   bool get isNotEmpty => _map.isNotEmpty;
-  V get first => _map[_map.keys.first];
-  V get single => _map[_map.keys.single];
-  V get last => _map[_map.keys.last];
+  V get first => _map[_map.keys.first] as V;
+  V get single => _map[_map.keys.single] as V;
+  V get last => _map[_map.keys.last] as V;
 
   Iterator<V> get iterator => _MapBaseValueIterator<K, V>(_map);
 }
@@ -322,7 +322,7 @@ class MapView<K, V> implements Map<K, V> {
   const MapView(Map<K, V> map) : _map = map;
 
   Map<RK, RV> cast<RK, RV>() => _map.cast<RK, RV>();
-  V operator [](Object key) => _map[key];
+  V? operator [](Object? key) => _map[key];
   void operator []=(K key, V value) {
     _map[key] = value;
   }
@@ -336,8 +336,8 @@ class MapView<K, V> implements Map<K, V> {
   }
 
   V putIfAbsent(K key, V ifAbsent()) => _map.putIfAbsent(key, ifAbsent);
-  bool containsKey(Object key) => _map.containsKey(key);
-  bool containsValue(Object value) => _map.containsValue(value);
+  bool containsKey(Object? key) => _map.containsKey(key);
+  bool containsValue(Object? value) => _map.containsValue(value);
   void forEach(void action(K key, V value)) {
     _map.forEach(action);
   }
@@ -346,7 +346,7 @@ class MapView<K, V> implements Map<K, V> {
   bool get isNotEmpty => _map.isNotEmpty;
   int get length => _map.length;
   Iterable<K> get keys => _map.keys;
-  V remove(Object key) => _map.remove(key);
+  V? remove(Object? key) => _map.remove(key);
   String toString() => _map.toString();
   Iterable<V> get values => _map.values;
 

sdk_nnbd/lib/collection/queue.dart

@@ -116,8 +116,8 @@ class _DoubleLink<Link extends _DoubleLink<Link>> {
   void _link(Link? previous, Link? next) {
     _nextLink = next;
     _previousLink = previous;
-    if (previous != null) previous!._nextLink = this as Link;
-    if (next != null) next!._previousLink = this as Link;
+    if (previous != null) previous._nextLink = this as Link;
+    if (next != null) next._previousLink = this as Link;
   }
 
   void _unlink() {
@@ -344,7 +344,7 @@ class DoubleLinkedQueue<E> extends Iterable<E> implements Queue<E> {
     return result;
   }
 
-  bool remove(Object o) {
+  bool remove(Object? o) {
     _DoubleLinkedQueueEntry<E> entry =
         _sentinel._nextLink as _DoubleLinkedQueueEntry<E>;
     while (!identical(entry, _sentinel)) {

sdk_nnbd/lib/collection/set.dart

@@ -87,8 +87,8 @@ abstract class SetMixin<E> implements Set<E> {
     removeAll(toRemove);
   }
 
-  bool containsAll(Iterable<Object> other) {
-    for (Object o in other) {
+  bool containsAll(Iterable<Object?> other) {
+    for (var o in other) {
       if (!contains(o)) return false;
     }
     return true;
@@ -98,15 +98,15 @@ abstract class SetMixin<E> implements Set<E> {
     return toSet()..addAll(other);
   }
 
-  Set<E> intersection(Set<Object> other) {
+  Set<E> intersection(Set<Object?> other) {
     Set<E> result = toSet();
     for (E element in this) {
       if (!other.contains(element)) result.remove(element);
     }
     return result;
   }
 
-  Set<E> difference(Set<Object> other) {
+  Set<E> difference(Set<Object?> other) {
     Set<E> result = toSet();
     for (E element in this) {
       if (other.contains(element)) result.remove(element);
@@ -323,15 +323,15 @@ abstract class _SetBase<E> implements Set<E> {
 
   Set<R> cast<R>() => Set.castFrom<E, R>(this, newSet: _newSimilarSet);
 
-  Set<E> difference(Set<Object> other) {
+  Set<E> difference(Set<Object?> other) {
     Set<E> result = _newSet();
     for (var element in this) {
       if (!other.contains(element)) result.add(element);
     }
     return result;
   }
 
-  Set<E> intersection(Set<Object> other) {
+  Set<E> intersection(Set<Object?> other) {
     Set<E> result = _newSet();
     for (var element in this) {
       if (other.contains(element)) result.add(element);

sdk_nnbd/lib/collection/splay_tree.dart

@@ -528,12 +528,12 @@ abstract class _SplayTreeIterator<K, T> implements Iterator<T> {
       // Don't include the root, start at the next element after the root.
       _findLeftMostDescendent(tree._root!.right);
     } else {
-      _workList.add(tree._root);
+      _workList.add(tree._root!);
     }
   }
 
-  T? get current {
-    if (_currentNode == null) return null;
+  T get current {
+    if (_currentNode == null) return null as T;
     return _getValue(_currentNode!);
   }
 

sdk_nnbd/lib/internal/cast.dart

@@ -270,8 +270,8 @@ class CastMap<SK, SV, K, V> extends MapBase<K, V> {
     _source[key as SK] = value as SV;
   }
 
-  V putIfAbsent(K key, V ifAbsent()) => _source.putIfAbsent(
-      key as SK, (ifAbsent == null) ? null : () => ifAbsent() as SV) as V;
+  V putIfAbsent(K key, V Function() ifAbsent) =>
+      _source.putIfAbsent(key as SK, () => ifAbsent() as SV) as V;
 
   void addAll(Map<K, V> other) {
     _source.addAll(new CastMap<K, V, SK, SV>(other));