Add convenience methods.

Author: JimBobSquarePants

src/ImageSharp.Web/Commands/CommandCollection.cs

@@ -55,13 +55,12 @@ public IEnumerable<string> Keys
         {
             get
             {
-                if (this.TryGetValue(key, out KeyValuePair<string, string> item))
+                if (!this.TryGetValue(key, out string value))
                 {
-                    return item.Value;
+                    ThrowKeyNotFound();
                 }
 
-                ThrowKeyNotFound();
-                return default;
+                return value;
             }
 
             set
@@ -72,11 +71,55 @@ public IEnumerable<string> Keys
                 }
                 else
                 {
-                    this.Add(new(key, value));
+                    this.Add(key, value);
                 }
             }
         }
 
+        /// <summary>
+        /// Adds an element with the provided key and value to the <see cref="CommandCollection"/>.
+        /// </summary>
+        /// <param name="key">The <see cref="string"/> to use as the key of the element to add.</param>
+        /// <param name="value">The <see cref="string"/> to use as the value of the element to add.</param>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is null.</exception>
+        public void Add(string key, string value) => this.Add(new(key, value));
+
+        /// <summary>
+        /// Inserts an element into the <see cref="CommandCollection"/> at the
+        /// specified index.
+        /// </summary>
+        /// <param name="index">The zero-based index at which item should be inserted.</param>
+        /// <param name="key">The <see cref="string"/> to use as the key of the element to insert.</param>
+        /// <param name="value">The <see cref="string"/> to use as the value of the element to insert.</param>
+        /// <exception cref="ArgumentOutOfRangeException">index is less than zero. -or- index is greater than <see cref="P:CommandCollection.Count"/>.</exception>
+        public void Insert(int index, string key, string value) => this.Insert(index, new(key, value));
+
+        /// <summary>
+        /// Gets the value associated with the specified key.
+        /// </summary>
+        /// <param name="key">The key whose value to get.</param>
+        /// <param name="value">
+        /// When this method returns, the value associated with the specified key, if the
+        /// key is found; otherwise, the default value for the type of the value parameter.
+        /// This parameter is passed uninitialized.
+        /// </param>
+        /// <returns>
+        /// <see langword="true"/> if the object that implements <see cref="CommandCollection"/> contains
+        /// an element with the specified key; otherwise, <see langword="false"/>.
+        /// </returns>
+        /// <exception cref="ArgumentNullException"><paramref name="key"/> is null.</exception>
+        public bool TryGetValue(string key, out string value)
+        {
+            if (this.TryGetValue(key, out KeyValuePair<string, string> keyValue))
+            {
+                value = keyValue.Value;
+                return true;
+            }
+
+            value = default;
+            return false;
+        }
+
         /// <summary>
         /// Searches for an element that matches the conditions defined by the specified
         /// predicate, and returns the zero-based index of the first occurrence within the
@@ -109,6 +152,25 @@ public int FindIndex(Predicate<string> match)
             return -1;
         }
 
+        /// <summary>
+        /// Searches for the specified key and returns the zero-based index of the first
+        /// occurrence within the entire <see cref="CommandCollection"/>.
+        /// </summary>
+        /// <param name="key">The key to locate in the <see cref="CommandCollection"/>.</param>
+        /// <returns>
+        /// The zero-based index of the first occurrence of key within the entire <see cref="CommandCollection"/>,
+        /// if found; otherwise, -1.
+        /// </returns>
+        public int IndexOf(string key)
+        {
+            if (this.TryGetValue(key, out KeyValuePair<string, string> item))
+            {
+                return this.IndexOf(item);
+            }
+
+            return -1;
+        }
+
         /// <inheritdoc/>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         protected override string GetKeyForItem(KeyValuePair<string, string> item) => item.Key;

tests/ImageSharp.Web.Tests/Commands/CommandCollectionTests.cs

@@ -48,6 +48,26 @@ public void CanInsertCommands()
             Assert.Equal(0, collection.IndexOf(kv2));
         }
 
+        [Fact]
+        public void CanInsertCommandsViaKey()
+        {
+            KeyValuePair<string, string> kv1 = new("a", "b");
+            KeyValuePair<string, string> kv2 = new("c", "d");
+
+            CommandCollection collection = new();
+            collection.Add(kv1);
+            Assert.Single(collection);
+
+            collection.Insert(0, kv2.Key, kv2.Value);
+            Assert.Equal(2, collection.Count);
+
+            Assert.Equal(kv1.Value, collection[kv1.Key]);
+            Assert.Equal(kv2.Value, collection[kv2.Key]);
+
+            Assert.Equal(1, collection.IndexOf(kv1));
+            Assert.Equal(0, collection.IndexOf(kv2));
+        }
+
         [Fact]
         public void CanSetCommandsViaIndex()
         {
@@ -148,10 +168,12 @@ public void KeysAreOrdered()
                 collection.Insert(0, new(key, null));
             }
 
-            int counter = keys.Length - 1;
+            int index = 0;
+            int offset = keys.Length - 1;
             foreach (string key in collection.Keys)
             {
-                Assert.Equal(keys[counter--], key);
+                Assert.Equal(index++, collection.IndexOf(key));
+                Assert.Equal(keys[offset--], key);
             }
         }