Code Action for Replacing Deprecated Unit Type(#73) (#118)

src/QsCompiler/CompilationManager/DiagnosticTools.cs

@@ -197,6 +197,15 @@ internal static Func<Diagnostic, bool> ErrorType(params ErrorCode[] types)
             return m => m.Severity == DiagnosticSeverity.Error && codes.Contains(m.Code);
         }
 
+        /// <summary>
+        /// Returns true if the WarningType of the given Diagnostic is one of the given types.
+        /// </summary>
+        internal static Func<Diagnostic, bool> WarningType(params WarningCode[] types)
+        {
+            var codes = types.Select(err => err.Code());
+            return m => m.Severity == DiagnosticSeverity.Warning && codes.Contains(m.Code);
+        }
+
         /// <summary>
         /// Returns true if the given diagnostics is an error.
         /// </summary>

src/QsCompiler/CompilationManager/EditorSupport/CodeActions.cs

@@ -133,5 +133,29 @@ private static IEnumerable<NonNullable<string>> NamespaceSuggestionsForTypeAtPos
                 .Select(SuggestedOpenDirective);
             return suggestionsForIds.Concat(suggestionsForTypes);
         }
+
+        /// <summary>
+        /// Returns a sequence of suggestions on how deprecated syntax can be updated based on the generated diagnostics, 
+        /// and given the file for which those diagnostics were generated. 
+        /// Returns an empty enumerable if any of the given arguments is null. 
+        /// </summary>
+        internal static IEnumerable<(string, WorkspaceEdit)> SuggestionsForDeprecatedSyntax
+            (this FileContentManager file, IEnumerable<Diagnostic> diagnostics)
+        {
+            if (file == null || diagnostics == null) return Enumerable.Empty<(string, WorkspaceEdit)>();
+            var deprecatedUnitTypes = diagnostics.Where(DiagnosticTools.WarningType(WarningCode.DeprecatedUnitType));
+            if (!deprecatedUnitTypes.Any()) return Enumerable.Empty<(string, WorkspaceEdit)>();
+
+            // Suggestion for replacing deprecated unit types
+            (string, WorkspaceEdit) EditAtPosition(string text, Position start, Position end)
+            {
+                var edit = new TextEdit { Range = new Range { Start = start, End = end }, NewText = text };
+                return ("Replace with \"" + $"{text}" + "\"", file.GetWorkspaceEdit(edit));
+            }
+
+            var suggestionsForUnitType = deprecatedUnitTypes
+                .Select(d => EditAtPosition(Keywords.qsUnit.id, d.Range.Start, d.Range.End));
+            return suggestionsForUnitType;
+        }
     }
 }

src/QsCompiler/CompilationManager/EditorSupport/EditorCommands.cs

@@ -112,7 +112,8 @@ public static ImmutableDictionary<string, WorkspaceEdit> CodeActions(this FileCo
             if (range?.Start == null || range.End == null || file == null || !Utils.IsValidRange(range, file)) return null;
             var suggestionsForUnknownIds = file.SuggestionsForUnknownIdentifiers(compilation, range.Start.Line, context?.Diagnostics);
             var suggestionsForAmbiguousIds = file.SuggestionsForAmbiguousIdentifiers(compilation, context?.Diagnostics);
-            return suggestionsForUnknownIds.Concat(suggestionsForAmbiguousIds)
+            var suggestionsForDeprecatedSyntax = file.SuggestionsForDeprecatedSyntax(context?.Diagnostics);
+            return suggestionsForUnknownIds.Concat(suggestionsForAmbiguousIds).Concat(suggestionsForDeprecatedSyntax)
                 .ToImmutableDictionary(s => s.Item1, s => s.Item2);
         }