Handle comment help completion request

Author: Kapil Borle

src/PowerShellEditorServices.Protocol/LanguageServer/CommentHelpRequest.cs

@@ -10,12 +10,12 @@ namespace Microsoft.PowerShell.EditorServices.Protocol.LanguageServer
     class CommentHelpRequest
     {
         public static readonly RequestType<CommentHelpRequestParams, CommentHelpRequestResult, object, object> Type
-            = RequestType<CommentHelpRequestParams, CommentHelpRequestResult, object, object>.Create("powershell/getCommentHelp");
+            = RequestType<CommentHelpRequestParams, CommentHelpRequestResult, object, object>.Create("powerShell/getCommentHelp");
     }
 
     public class CommentHelpRequestResult
     {
-        public string[] content;
+        public string[] Content { get; set; }
     }
 
     public class CommentHelpRequestParams

src/PowerShellEditorServices.Protocol/Server/LanguageServer.cs

@@ -21,6 +21,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using DebugAdapterMessages = Microsoft.PowerShell.EditorServices.Protocol.DebugAdapter;
+using System.Collections;
 
 namespace Microsoft.PowerShell.EditorServices.Protocol.Server
 {
@@ -149,7 +150,7 @@ protected override void Initialize()
             this.SetRequestHandler(ScriptRegionRequest.Type, this.HandleGetFormatScriptRegionRequest);
 
             this.SetRequestHandler(GetPSHostProcessesRequest.Type, this.HandleGetPSHostProcessesRequest);
-
+            this.SetRequestHandler(CommentHelpRequest.Type, this.HandleCommentHelpRequest);
             // Initialize the extension service
             // TODO: This should be made awaited once Initialize is async!
             this.editorSession.ExtensionService.Initialize(
@@ -243,9 +244,9 @@ private async Task HandleSetPSSARulesRequest(
                 var ruleInfos = dynParams.ruleInfos;
                 foreach (dynamic ruleInfo in ruleInfos)
                 {
-                    if ((Boolean) ruleInfo.isEnabled)
+                    if ((Boolean)ruleInfo.isEnabled)
                     {
-                        activeRules.Add((string) ruleInfo.name);
+                        activeRules.Add((string)ruleInfo.name);
                     }
                 }
                 editorSession.AnalysisService.ActiveRules = activeRules.ToArray();
@@ -309,7 +310,8 @@ private async Task HandleScriptFileMarkersRequest(
             var markers = await editorSession.AnalysisService.GetSemanticMarkersAsync(
                 editorSession.Workspace.GetFile(requestParams.fileUri),
                 editorSession.AnalysisService.GetPSSASettingsHashtable(requestParams.settings));
-            await requestContext.SendResult(new ScriptFileMarkerRequestResultParams {
+            await requestContext.SendResult(new ScriptFileMarkerRequestResultParams
+            {
                 markers = markers
             });
         }
@@ -571,7 +573,7 @@ protected async Task HandleDidChangeConfigurationNotification(
         {
             bool oldLoadProfiles = this.currentSettings.EnableProfileLoading;
             bool oldScriptAnalysisEnabled =
-                this.currentSettings.ScriptAnalysis.Enable.HasValue ? this.currentSettings.ScriptAnalysis.Enable.Value : false ;
+                this.currentSettings.ScriptAnalysis.Enable.HasValue ? this.currentSettings.ScriptAnalysis.Enable.Value : false;
             string oldScriptAnalysisSettingsPath =
                 this.currentSettings.ScriptAnalysis.SettingsPath;
 
@@ -1074,6 +1076,50 @@ protected async Task HandleGetPSHostProcessesRequest(
             await requestContext.SendResult(psHostProcesses.ToArray());
         }
 
+        protected async Task HandleCommentHelpRequest(
+           CommentHelpRequestParams requestParams,
+           RequestContext<CommentHelpRequestResult> requestContext)
+        {
+            var scriptFile = EditorSession.Workspace.GetFile(requestParams.DocumentUri);
+            var expectedFunctionLine = requestParams.TriggerPosition.Line + 2;
+            var functionDefinitionAst = EditorSession.LanguageService.GetFunctionDefinitionAtLine(
+                scriptFile,
+                expectedFunctionLine);
+            var result = new CommentHelpRequestResult()
+            {
+                Content = new string[] { "" }
+            };
+
+            if (functionDefinitionAst != null)
+            {
+                var settings = new Dictionary<string, Hashtable>();
+                var ruleSettings = new Hashtable();
+                ruleSettings.Add("ExportedOnly", false);
+                ruleSettings.Add("Enable", true);
+                settings.Add("PSProvideCommentHelp", ruleSettings);
+                var pssaSettings = EditorSession.AnalysisService.GetPSSASettingsHashtable(settings);
+
+                // todo create a semantic marker api that take only string
+                var analysisResults = await EditorSession.AnalysisService.GetSemanticMarkersAsync(
+                    scriptFile,
+                    pssaSettings);
+
+                var analysisResult = analysisResults?.FirstOrDefault(x =>
+                {
+                    return x.Correction != null
+                        && x.Correction.Edits[0].StartLineNumber == expectedFunctionLine;
+                });
+
+                if (analysisResult != null)
+                {
+                    // find the analysis result whose correction starts on
+                    result.Content = analysisResult.Correction.Edits[0].Text.Split('\n').Select(x => x.Trim('\r')).ToArray();
+                }
+            }
+
+            await requestContext.SendResult(result);
+        }
+
         private bool IsQueryMatch(string query, string symbolName)
         {
             return symbolName.IndexOf(query, StringComparison.OrdinalIgnoreCase) >= 0;
@@ -1136,12 +1182,12 @@ protected Task HandleEvaluateRequest(
                     // Return an empty result since the result value is irrelevant
                     // for this request in the LanguageServer
                     return
-                        requestContext.SendResult(
-                            new DebugAdapterMessages.EvaluateResponseBody
-                            {
-                                Result = "",
-                                VariablesReference = 0
-                            });
+                    requestContext.SendResult(
+                        new DebugAdapterMessages.EvaluateResponseBody
+                        {
+                            Result = "",
+                            VariablesReference = 0
+                        });
                 });
 
             return Task.FromResult(true);

src/PowerShellEditorServices/Language/LanguageService.cs

@@ -115,7 +115,7 @@ await AstOperations.GetCompletions(
 
                     return completionResults;
                 }
-                catch(ArgumentException e)
+                catch (ArgumentException e)
                 {
                     // Bad completion results could return an invalid
                     // replacement range, catch that here
@@ -231,15 +231,17 @@ public FindOccurrencesResult FindSymbolsInFile(ScriptFile scriptFile)
                 AstOperations
                     .FindSymbolsInDocument(scriptFile.ScriptAst, this.powerShellContext.LocalPowerShellVersion.Version)
                     .Select(
-                        reference => {
+                        reference =>
+                        {
                             reference.SourceLine =
                                 scriptFile.GetLine(reference.ScriptRegion.StartLineNumber);
                             reference.FilePath = scriptFile.FilePath;
                             return reference;
                         });
 
             return
-                new FindOccurrencesResult {
+                new FindOccurrencesResult
+                {
                     FoundOccurrences = symbolReferencesinFile
                 };
         }
@@ -267,7 +269,7 @@ public async Task<FindReferencesResult> FindReferencesOfSymbol(
 
                 // We want to look for references first in referenced files, hence we use ordered dictionary
                 var fileMap = new OrderedDictionary(StringComparer.OrdinalIgnoreCase);
-                foreach(ScriptFile file in referencedFiles)
+                foreach (ScriptFile file in referencedFiles)
                 {
                     fileMap.Add(file.FilePath, file);
                 }
@@ -520,6 +522,17 @@ public ScriptRegion FindSmallestStatementAstRegion(
             return ScriptRegion.Create(ast.Extent);
         }
 
+        public FunctionDefinitionAst GetFunctionDefinitionAtLine(
+            ScriptFile scriptFile,
+            int lineNumber)
+        {
+            var functionDefinitionAst = scriptFile.ScriptAst.Find(
+                ast => ast is FunctionDefinitionAst && ast.Extent.StartLineNumber == lineNumber,
+                true);
+
+            return functionDefinitionAst as FunctionDefinitionAst;
+        }
+
         #endregion
 
         #region Private Fields