Add a powerShell/getModule handler for module metadata

The Command Explorer groups commands under versioned module nodes and shows a
tooltip on hover. Add a `getModule` request that returns a single module's
metadata (version, description, path, author, company, project URI, required
PowerShell version) so the client can populate those tooltips lazily, and
register the handler in `PsesLanguageServer`.

Drafted by Copilot (Claude Opus 4.8).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: andyleejordan

src/PowerShellEditorServices/Server/PsesLanguageServer.cs

@@ -121,6 +121,7 @@ public async Task StartAsync()
                     .WithHandler<GetCommentHelpHandler>()
                     .WithHandler<EvaluateHandler>()
                     .WithHandler<GetCommandHandler>()
+                    .WithHandler<GetModuleHandler>()
                     .WithHandler<ShowHelpHandler>()
                     .WithHandler<ExpandAliasHandler>()
                     .WithHandler<PsesSemanticTokensHandler>()

src/PowerShellEditorServices/Services/PowerShell/Handlers/GetModuleHandler.cs

@@ -0,0 +1,125 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+using System.Collections.Generic;
+using System.Management.Automation;
+using System.Threading;
+using System.Threading.Tasks;
+using MediatR;
+using OmniSharp.Extensions.JsonRpc;
+using Microsoft.PowerShell.EditorServices.Services.PowerShell;
+using Microsoft.PowerShell.EditorServices.Services.PowerShell.Execution;
+
+namespace Microsoft.PowerShell.EditorServices.Handlers
+{
+    [Serial, Method("powerShell/getModule", Direction.ClientToServer)]
+    internal interface IGetModuleHandler : IJsonRpcRequestHandler<GetModuleParams, PSModuleMessage> { }
+
+    internal class GetModuleParams : IRequest<PSModuleMessage>
+    {
+        /// <summary>
+        /// The name of the module to retrieve metadata for.
+        /// </summary>
+        public string Name { get; set; }
+
+        /// <summary>
+        /// An optional specific version of the module. When omitted, the newest
+        /// available version is returned.
+        /// </summary>
+        public string Version { get; set; }
+    }
+
+    /// <summary>
+    /// Describes the metadata for a single PowerShell module, used to populate
+    /// the Command Explorer's module tooltips.
+    /// </summary>
+    internal class PSModuleMessage
+    {
+        public string Name { get; set; }
+        public string Version { get; set; }
+        public string Description { get; set; }
+        public string Path { get; set; }
+        public string Author { get; set; }
+        public string CompanyName { get; set; }
+        public string ProjectUri { get; set; }
+        public string PowerShellVersion { get; set; }
+    }
+
+    internal class GetModuleHandler : IGetModuleHandler
+    {
+        private readonly IInternalPowerShellExecutionService _executionService;
+
+        public GetModuleHandler(IInternalPowerShellExecutionService executionService) => _executionService = executionService;
+
+        public async Task<PSModuleMessage> Handle(GetModuleParams request, CancellationToken cancellationToken)
+        {
+            if (string.IsNullOrEmpty(request.Name))
+            {
+                return null;
+            }
+
+            // Resolve a module's metadata from the available modules, pinning to a
+            // specific version when requested and otherwise taking the newest.
+            const string GetModuleScript = @"
+                [System.Diagnostics.DebuggerHidden()]
+                [CmdletBinding()]
+                param (
+                    [String]$Name,
+                    [String]$Version
+                )
+                $modules = Microsoft.PowerShell.Core\Get-Module -ListAvailable -Name $Name -ErrorAction Ignore
+                if ($Version) {
+                    $modules = $modules | Microsoft.PowerShell.Core\Where-Object { $_.Version.ToString() -eq $Version }
+                }
+                $module = $modules | Microsoft.PowerShell.Utility\Sort-Object Version -Descending | Microsoft.PowerShell.Utility\Select-Object -First 1
+                if ($null -eq $module) {
+                    return
+                }
+                [PSCustomObject]@{
+                    Name = $module.Name
+                    Version = $module.Version.ToString()
+                    Description = $module.Description
+                    Path = $module.Path
+                    Author = $module.Author
+                    CompanyName = $module.CompanyName
+                    ProjectUri = if ($module.ProjectUri) { $module.ProjectUri.ToString() } else { '' }
+                    PowerShellVersion = if ($module.PowerShellVersion) { $module.PowerShellVersion.ToString() } else { '' }
+                }
+                ";
+
+            PSCommand getModuleCommand = new PSCommand()
+                .AddScript(GetModuleScript, useLocalScope: true)
+                .AddParameter("Name", request.Name)
+                .AddParameter("Version", request.Version);
+
+            IReadOnlyList<PSObject> results = await _executionService.ExecutePSCommandAsync<PSObject>(
+                getModuleCommand,
+                cancellationToken,
+                new PowerShellExecutionOptions
+                {
+                    ThrowOnError = false
+                }).ConfigureAwait(false);
+
+            PSObject result = results is { Count: > 0 } ? results[0] : null;
+            if (result is null)
+            {
+                return null;
+            }
+
+            return new PSModuleMessage
+            {
+                Name = GetPropertyString(result, "Name"),
+                Version = GetPropertyString(result, "Version"),
+                Description = GetPropertyString(result, "Description"),
+                Path = GetPropertyString(result, "Path"),
+                Author = GetPropertyString(result, "Author"),
+                CompanyName = GetPropertyString(result, "CompanyName"),
+                ProjectUri = GetPropertyString(result, "ProjectUri"),
+                PowerShellVersion = GetPropertyString(result, "PowerShellVersion")
+            };
+        }
+
+        private static string GetPropertyString(PSObject psObject, string propertyName)
+            => psObject.Properties[propertyName]?.Value as string ?? string.Empty;
+    }
+}

test/PowerShellEditorServices.Test.E2E/LanguageServerProtocolMessageTests.cs

@@ -1300,6 +1300,60 @@ await PsesLanguageClient
             Assert.Equal("Get-ChildItem | Where-Object Name | ForEach-Object Name", expandAliasResult.Text);
         }
 
+        [SkippableFact]
+        public async Task CanSendGetModuleRequestAsync()
+        {
+            Skip.If(PsesStdioLanguageServerProcessHost.RunningInConstrainedLanguageMode,
+                "The getModule request's script doesn't work in Constrained Language Mode.");
+
+            PSModuleMessage module =
+                await PsesLanguageClient
+                    .SendRequest(
+                        "powerShell/getModule",
+                        new GetModuleParams
+                        {
+                            Name = "Microsoft.PowerShell.Management"
+                        })
+                    .Returning<PSModuleMessage>(CancellationToken.None);
+
+            Assert.NotNull(module);
+            Assert.Equal("Microsoft.PowerShell.Management", module.Name);
+            Assert.NotEmpty(module.Version);
+            Assert.NotEmpty(module.Path);
+
+            // Pinning to the resolved version should return that same version,
+            // exercising the handler's explicit-version branch.
+            PSModuleMessage pinned =
+                await PsesLanguageClient
+                    .SendRequest(
+                        "powerShell/getModule",
+                        new GetModuleParams
+                        {
+                            Name = "Microsoft.PowerShell.Management",
+                            Version = module.Version
+                        })
+                    .Returning<PSModuleMessage>(CancellationToken.None);
+
+            Assert.NotNull(pinned);
+            Assert.Equal(module.Version, pinned.Version);
+        }
+
+        [Fact]
+        public async Task CanSendGetModuleRequestForMissingModuleAsync()
+        {
+            PSModuleMessage module =
+                await PsesLanguageClient
+                    .SendRequest(
+                        "powerShell/getModule",
+                        new GetModuleParams
+                        {
+                            Name = $"ThisModuleDoesNotExist-{Guid.NewGuid():N}"
+                        })
+                    .Returning<PSModuleMessage>(CancellationToken.None);
+
+            Assert.Null(module);
+        }
+
         [Fact]
         public async Task CanSendSemanticTokenRequestAsync()
         {