Resurrect alias support for FindReferences

In ancient times, commit 633e36b
implemented support for aliases when finding references. This was
removed during the OmniSharp rewrite because it needed the pipeline
thread, which was not yet available. With that work complete, this can
now be resurrected.

Author: andyleejordan

src/PowerShellEditorServices/Services/Symbols/SymbolsService.cs

@@ -39,7 +39,8 @@ internal class SymbolsService
 
         private readonly ConcurrentDictionary<string, ICodeLensProvider> _codeLensProviders;
         private readonly ConcurrentDictionary<string, IDocumentSymbolProvider> _documentSymbolProviders;
-
+        private readonly Dictionary<String, List<String>> _cmdletToAliasDictionary;
+        private readonly Dictionary<String, String> _aliasToCmdletDictionary;
         #endregion
 
         #region Constructors
@@ -84,6 +85,10 @@ public SymbolsService(
             {
                 _documentSymbolProviders.TryAdd(documentSymbolProvider.ProviderId, documentSymbolProvider);
             }
+
+            _cmdletToAliasDictionary = new Dictionary<String, List<String>>(StringComparer.OrdinalIgnoreCase);
+            _aliasToCmdletDictionary = new Dictionary<String, String>(StringComparer.OrdinalIgnoreCase);
+            GetAliases();
         }
 
         #endregion
@@ -186,8 +191,6 @@ public List<SymbolReference> FindReferencesOfSymbol(
                 return null;
             }
 
-            // NOTE: we use to make sure aliases were loaded but took it out because we needed the pipeline thread.
-
             // We want to look for references first in referenced files, hence we use ordered dictionary
             // TODO: File system case-sensitivity is based on filesystem not OS, but OS is a much cheaper heuristic
             var fileMap = RuntimeInformation.IsOSPlatform(OSPlatform.Linux)
@@ -221,7 +224,8 @@ public List<SymbolReference> FindReferencesOfSymbol(
                 IEnumerable<SymbolReference> references = AstOperations.FindReferencesOfSymbol(
                     file.ScriptAst,
                     foundSymbol,
-                    needsAliases: false);
+                    _cmdletToAliasDictionary,
+                    _aliasToCmdletDictionary);
 
                 foreach (SymbolReference reference in references)
                 {
@@ -490,6 +494,36 @@ await CommandHelpers.GetCommandInfoAsync(
             return foundDefinition;
         }
 
+        /// <summary>
+        /// Gets all aliases found in the runspace
+        /// </summary>
+        private async void GetAliases()
+        {
+            IEnumerable<CommandInfo> aliases = await _executionService.ExecuteDelegateAsync<IEnumerable<CommandInfo>>(
+                nameof(GetAliases),
+                PowerShell.Execution.ExecutionOptions.Default,
+                (pwsh, _) =>
+                {
+                    CommandInvocationIntrinsics invokeCommand = pwsh.Runspace.SessionStateProxy.InvokeCommand;
+                    return invokeCommand.GetCommands("*", CommandTypes.Alias, nameIsPattern: true);
+                },
+                System.Threading.CancellationToken.None).ConfigureAwait(false);
+
+            foreach (AliasInfo aliasInfo in aliases)
+            {
+                if (!_cmdletToAliasDictionary.ContainsKey(aliasInfo.Definition))
+                {
+                    _cmdletToAliasDictionary.Add(aliasInfo.Definition, new List<String>() { aliasInfo.Name });
+                }
+                else
+                {
+                    _cmdletToAliasDictionary[aliasInfo.Definition].Add(aliasInfo.Name);
+                }
+
+                _aliasToCmdletDictionary.Add(aliasInfo.Name, aliasInfo.Definition);
+            }
+        }
+
         /// <summary>
         /// Gets a path from a dot-source symbol.
         /// </summary>

test/PowerShellEditorServices.Test.Shared/References/FindsReferencesOnBuiltInCommandWithAlias.cs

@@ -17,16 +17,4 @@ public static class FindsReferencesOnBuiltInCommandWithAliasData
             endColumnNumber: 0,
             endOffset: 0);
     }
-    public static class FindsReferencesOnBuiltInAliasData
-    {
-        public static readonly ScriptRegion SourceDetails = new(
-            file: TestUtilities.NormalizePath("References/SimpleFile.ps1"),
-            text: string.Empty,
-            startLineNumber: 15,
-            startColumnNumber: 2,
-            startOffset: 0,
-            endLineNumber: 0,
-            endColumnNumber: 0,
-            endOffset: 0);
-    }
 }

test/PowerShellEditorServices.Test/Language/SymbolsServiceTests.cs

@@ -203,20 +203,12 @@ public void FindsOccurrencesOnParameter()
             Assert.Equal(3, occurrencesResult[occurrencesResult.Count - 1].ScriptRegion.StartLineNumber);
         }
 
-        [Fact(Skip = "TODO Fix this test. A possible bug in PSES product code.")]
+        [Fact]
         public void FindsReferencesOnCommandWithAlias()
         {
             List<SymbolReference> referencesResult = GetReferences(FindsReferencesOnBuiltInCommandWithAliasData.SourceDetails);
             Assert.Equal(4, referencesResult.Count);
             Assert.Equal("gci", referencesResult[1].SymbolName);
-            Assert.Equal("Get-ChildItem", referencesResult[referencesResult.Count - 1].SymbolName);
-        }
-
-        [Fact(Skip = "TODO Fix this test. A possible bug in PSES product code.")]
-        public void FindsReferencesOnAlias()
-        {
-            List<SymbolReference> referencesResult = GetReferences(FindsReferencesOnBuiltInCommandWithAliasData.SourceDetails);
-            Assert.Equal(4, referencesResult.Count);
             Assert.Equal("dir", referencesResult[2].SymbolName);
             Assert.Equal("Get-ChildItem", referencesResult[referencesResult.Count - 1].SymbolName);
         }