Improve Pester document symbol reporting

This change improves how we report Pester document symbols, narrowing
the "symbol name" to just be the 'Describe "My Tests"' line rather than
the entire content of the test.  This makes the contents more easily
searchable and displayed correctly in VS Code.

Author: daviwil

src/PowerShellEditorServices/Language/SymbolReference.cs

@@ -48,14 +48,20 @@ public class SymbolReference
         /// Constructs and instance of a SymbolReference
         /// </summary>
         /// <param name="symbolType">The higher level type of the symbol</param>
+        /// <param name="symbolName">The name of the symbol</param>
         /// <param name="scriptExtent">The script extent of the symbol</param>
         /// <param name="filePath">The file path of the symbol</param>
         /// <param name="sourceLine">The line contents of the given symbol (defaults to empty string)</param>
-        public SymbolReference(SymbolType symbolType, IScriptExtent scriptExtent, string filePath = "", string sourceLine = "")
+        public SymbolReference(
+            SymbolType symbolType,
+            string symbolName,
+            IScriptExtent scriptExtent,
+            string filePath = "",
+            string sourceLine = "")
         {
             // TODO: Verify params
             this.SymbolType = symbolType;
-            this.SymbolName = scriptExtent.Text;
+            this.SymbolName = symbolName;
             this.ScriptRegion = ScriptRegion.Create(scriptExtent);
             this.FilePath = filePath;
             this.SourceLine = sourceLine;
@@ -67,5 +73,17 @@ public SymbolReference(SymbolType symbolType, IScriptExtent scriptExtent, string
             //    string.Format(
             //        "{0} {1}")
         }
+
+        /// <summary>
+        /// Constructs and instance of a SymbolReference
+        /// </summary>
+        /// <param name="symbolType">The higher level type of the symbol</param>
+        /// <param name="scriptExtent">The script extent of the symbol</param>
+        /// <param name="filePath">The file path of the symbol</param>
+        /// <param name="sourceLine">The line contents of the given symbol (defaults to empty string)</param>
+        public SymbolReference(SymbolType symbolType, IScriptExtent scriptExtent, string filePath = "", string sourceLine = "")
+            : this(symbolType, scriptExtent.Text, scriptExtent, filePath, sourceLine)
+        {
+        }
     }
 }

src/PowerShellEditorServices/Symbols/PesterDocumentSymbolProvider.cs

@@ -16,6 +16,8 @@ namespace Microsoft.PowerShell.EditorServices.Symbols
     /// </summary>
     public class PesterDocumentSymbolProvider : FeatureProviderBase, IDocumentSymbolProvider
     {
+        private static char[] DefinitionTrimChars = new char[] { ' ', '{' };
+
         IEnumerable<SymbolReference> IDocumentSymbolProvider.ProvideDocumentSymbols(
             ScriptFile scriptFile)
         {
@@ -41,11 +43,20 @@ IEnumerable<SymbolReference> IDocumentSymbolProvider.ProvideDocumentSymbols(
             },
             true);
 
-            return commandAsts.Select(ast => new SymbolReference(
-                SymbolType.Function,
-                ast.Extent,
-                scriptFile.FilePath,
-                scriptFile.GetLine(ast.Extent.StartLineNumber)));
+            return commandAsts.Select(
+                ast => {
+                    var testDefinitionLine =
+                        scriptFile.GetLine(
+                            ast.Extent.StartLineNumber);
+
+                    return
+                        new SymbolReference(
+                            SymbolType.Function,
+                            testDefinitionLine.TrimEnd(DefinitionTrimChars),
+                            ast.Extent,
+                            scriptFile.FilePath,
+                            testDefinitionLine);
+                });
         }
     }
 }