expose Option.Completions, remove AddCompletions helper methods

src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt

@@ -192,6 +192,7 @@ System.CommandLine
     public System.Boolean AllowMultipleArgumentsPerToken { get; set; }
     public System.String ArgumentHelpName { get; set; }
     public ArgumentArity Arity { get; set; }
+    public System.Collections.Generic.List<System.Func<System.CommandLine.Completions.CompletionContext,System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem>>> Completions { get; }
     public System.Boolean IsRequired { get; set; }
     public System.Collections.Generic.List<System.Action<System.CommandLine.Parsing.OptionResult>> Validators { get; }
     public System.Type ValueType { get; }
@@ -209,9 +210,6 @@ System.CommandLine
     public Option<T> AcceptLegalFileNamesOnly()
     public Option<T> AcceptLegalFilePathsOnly()
     public Option<T> AcceptOnlyFromAmong(System.String[] values)
-    public Option<T> AddCompletions(System.String[] completions)
-    public Option<T> AddCompletions(System.Func<System.CommandLine.Completions.CompletionContext,System.Collections.Generic.IEnumerable<System.String>> completionsDelegate)
-    public Option<T> AddCompletions(System.Func<System.CommandLine.Completions.CompletionContext,System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem>> completionsDelegate)
     public System.Void SetDefaultValue(T value)
     public System.Void SetDefaultValueFactory(Func<T> defaultValueFactory)
   public static class OptionValidation

src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Directives_Suggest.cs

@@ -22,10 +22,16 @@ public void Setup()
         {
             _nullConsole = new NullConsole();
 
+            Option<string> fruitOption = new("--fruit");
+            fruitOption.Completions.Add("apple", "banana", "cherry");
+
+            Option<string> vegetableOption = new("--vegetable");
+            vegetableOption.Completions.Add("asparagus", "broccoli", "carrot");
+
             var eatCommand = new Command("eat")
             {
-                new Option<string>("--fruit").AddCompletions("apple", "banana", "cherry"),
-                new Option<string>("--vegetable").AddCompletions("asparagus", "broccoli", "carrot")
+                fruitOption,
+                vegetableOption
             };
 
             _testParser = new CommandLineBuilder(eatCommand)

src/System.CommandLine.Benchmarks/CommandLine/Perf_Suggestions.cs

@@ -14,7 +14,7 @@ namespace System.CommandLine.Benchmarks.CommandLine
     [BenchmarkCategory(Categories.CommandLine)]
     public class Perf_Suggestions
     {
-        private Symbol _testSymbol;
+        private Option _testSymbol;
         private ParseResult _testParseResult;
 
         /// <remarks>
@@ -36,8 +36,8 @@ private IEnumerable<Option> GenerateOptionsArray(int count)
         [GlobalSetup(Target = nameof(SuggestionsFromSymbol))]
         public void Setup_FromSymbol()
         {
-            _testSymbol = new Option<string>("--hello")
-                .AddCompletions(GenerateSuggestionsArray(TestSuggestionsCount));
+            _testSymbol = new Option<string>("--hello");
+            _testSymbol.Completions.Add(GenerateSuggestionsArray(TestSuggestionsCount));
         }
 
         [Benchmark]

src/System.CommandLine.Tests/CompletionTests.cs

@@ -24,8 +24,8 @@ public CompletionTests(ITestOutputHelper output)
         [Fact]
         public void Option_GetCompletions_returns_argument_completions_if_configured()
         {
-            var option = new Option<string>("--hello")
-                .AddCompletions("one", "two", "three");
+            var option = new Option<string>("--hello");
+            option.Completions.Add("one", "two", "three");
 
             var completions = option.GetCompletions();
 
@@ -210,17 +210,19 @@ public void When_an_option_has_a_default_value_it_will_still_be_suggested()
         public void Command_GetCompletions_can_access_ParseResult()
         {
             var originOption = new Option<string>("--origin");
+            var cloneOption = new Option<string>("--clone");
+
+            cloneOption.Completions.Add(ctx =>
+            {
+                var opt1Value = ctx.ParseResult.GetValue(originOption);
+                return !string.IsNullOrWhiteSpace(opt1Value) ? new[] { opt1Value } : Array.Empty<string>();
+            });
 
             var parser = new Parser(
                 new RootCommand
                 {
                     originOption,
-                    new Option<string>("--clone")
-                        .AddCompletions(ctx =>
-                        {
-                            var opt1Value = ctx.ParseResult.GetValue(originOption);
-                            return !string.IsNullOrWhiteSpace(opt1Value) ? new[] { opt1Value } : Array.Empty<string>();
-                        })
+                    cloneOption
                 });
 
             var result = parser.Parse("--origin test --clone ");
@@ -578,10 +580,12 @@ public void Option_GetCompletions_can_be_based_on_the_proximate_option_and_parti
         [Fact]
         public void Completions_can_be_provided_in_the_absence_of_validation()
         {
+            Option<string> option = new ("-t");
+            option.Completions.Add("vegetable", "mineral", "animal");
+
             var command = new Command("the-command")
                 {
-                    new Option<string>("-t")
-                        .AddCompletions("vegetable", "mineral", "animal")
+                    option
                 };
 
             command.Parse("the-command -t m")
@@ -621,10 +625,12 @@ public void Command_argument_completions_can_be_provided_using_a_delegate()
         [Fact]
         public void Option_argument_completions_can_be_provided_using_a_delegate()
         {
+            var option = new Option<string>("-x");
+            option.Completions.Add(_ => new[] { "vegetable", "mineral", "animal" });
+
             var command = new Command("the-command")
             {
-                new Option<string>("-x")
-                    .AddCompletions(_ => new [] { "vegetable", "mineral", "animal" })
+                option
             };
 
             var parseResult = command.Parse("the-command -x m");

src/System.CommandLine.Tests/OptionTests.cs

@@ -391,9 +391,6 @@ public void Option_of_T_fluent_APIs_return_Option_of_T()
         {
             Option<string> option = new Option<string>("--path")
                 .AcceptOnlyFromAmong("text")
-                .AddCompletions("test")
-                .AddCompletions(ctx => Array.Empty<string>())
-                .AddCompletions(ctx => Array.Empty<CompletionItem>())
                 .AcceptLegalFileNamesOnly()
                 .AcceptLegalFilePathsOnly();
 

src/System.CommandLine.Tests/SuggestDirectiveTests.cs

@@ -20,11 +20,11 @@ public class SuggestDirectiveTests
 
         public SuggestDirectiveTests()
         {
-            _fruitOption = new Option<string>("--fruit")
-                .AddCompletions("apple", "banana", "cherry");
+            _fruitOption = new Option<string>("--fruit");
+            _fruitOption.Completions.Add("apple", "banana", "cherry");
 
-            _vegetableOption = new Option<string>("--vegetable")
-                .AddCompletions(_ => new[] { "asparagus", "broccoli", "carrot" });
+            _vegetableOption = new Option<string>("--vegetable");
+            _vegetableOption.Completions.Add(_ => new[] { "asparagus", "broccoli", "carrot" });
 
             _eatCommand = new Command("eat")
             {

src/System.CommandLine/Option.cs

@@ -104,6 +104,11 @@ public override string Name
 
         internal bool HasValidators => _validators is not null && _validators.Count > 0;
 
+        /// <summary>
+        /// Gets the list of completion sources for the option.
+        /// </summary>
+        public List<Func<CompletionContext, IEnumerable<CompletionItem>>> Completions => Argument.Completions;
+
         /// <summary>
         /// Indicates whether a given alias exists on the option, regardless of its prefix.
         /// </summary>

src/System.CommandLine/Option{T}.cs

@@ -113,39 +113,6 @@ public Option<T> AcceptOnlyFromAmong(params string[] values)
             return this;
         }
 
-        /// <summary>
-        /// Adds completions for the option.
-        /// </summary>
-        /// <param name="completions">The completions to add.</param>
-        /// <returns>The configured option.</returns>
-        public Option<T> AddCompletions(params string[] completions)
-        {
-            _argument.Completions.Add(completions);
-            return this;
-        }
-
-        /// <summary>
-        /// Adds completions for the option.
-        /// </summary>
-        /// <param name="completionsDelegate">A function that will be called to provide completions.</param>
-        /// <returns>The configured option.</returns>
-        public Option<T> AddCompletions(Func<CompletionContext, IEnumerable<string>> completionsDelegate)
-        {
-            _argument.Completions.Add(completionsDelegate);
-            return this;
-        }
-
-        /// <summary>
-        /// Adds completions for the option.
-        /// </summary>
-        /// <param name="completionsDelegate">A function that will be called to provide completions.</param>
-        /// <returns>The configured option.</returns>
-        public Option<T> AddCompletions(Func<CompletionContext, IEnumerable<CompletionItem>> completionsDelegate)
-        {
-            _argument.Completions.Add(completionsDelegate);
-            return this;
-        }
-
         /// <summary>
         /// Configures the option to accept only values representing legal file paths.
         /// </summary>