Fixing for extending member from typing module (microsoft#1366)

CTrando · web-flow · commit 0c0074bec02e · 2019-07-23T12:48:51.000-07:00
* Fixing for extending a member from typing module
diff --git a/src/Analysis/Ast/Impl/Analyzer/Symbols/ClassEvaluator.cs b/src/Analysis/Ast/Impl/Analyzer/Symbols/ClassEvaluator.cs
@@ -18,6 +18,8 @@
 using System.Linq;
 using Microsoft.Python.Analysis.Analyzer.Evaluation;
 using Microsoft.Python.Analysis.Diagnostics;
+using Microsoft.Python.Analysis.Modules;
+using Microsoft.Python.Analysis.Specializations.Typing;
 using Microsoft.Python.Analysis.Types;
 using Microsoft.Python.Analysis.Values;
 using Microsoft.Python.Core;
@@ -117,17 +119,26 @@ private IEnumerable<IPythonType> ProcessBases(Scope outerScope) {
                 var expr = a.Expression;
                 var m = Eval.GetValueFromExpression(expr);
 
-                switch (m?.MemberType) {
-                    case PythonMemberType.Method:
-                    case PythonMemberType.Function:
-                    case PythonMemberType.Property:
-                    case PythonMemberType.Instance:
-                    case PythonMemberType.Variable when m is IPythonConstant:
-                        // all invalid types to inherit from
-                        ReportInvalidBase(a.ToCodeString(Eval.Ast, CodeFormattingOptions.Traditional));
+                switch (m) {
+                    // Allow any members from typing module
+                    // TODO handle typing module specialization better: https://github.com/microsoft/python-language-server/issues/1367
+                    case ILocatedMember l when l.DeclaringModule is TypingModule:
+                        TryAddBase(bases, a);
                         break;
                     default:
-                        TryAddBase(bases, a);
+                        switch (m?.MemberType) {
+                            case PythonMemberType.Method:
+                            case PythonMemberType.Function:
+                            case PythonMemberType.Property:
+                            case PythonMemberType.Instance:
+                            case PythonMemberType.Variable when m is IPythonConstant:
+                                // all invalid types to inherit from
+                                ReportInvalidBase(a.ToCodeString(Eval.Ast, CodeFormattingOptions.Traditional));
+                                break;
+                            default:
+                                TryAddBase(bases, a);
+                                break;
+                        }
                         break;
                 }
             }
diff --git a/src/Analysis/Ast/Test/LintInheritNonClassTests.cs b/src/Analysis/Ast/Test/LintInheritNonClassTests.cs
@@ -146,13 +146,6 @@ def method(self):
         }
 
 
-        /// <summary>
-        /// Because typing module is specialized with functions instead of classes,
-        /// we think that we are extending a function instead of a class so we would erroneously
-        /// give a diagnostic message
-        /// </summary>
-        /// <returns></returns>
-        [Ignore]
         [TestMethod, Priority(0)]
         public async Task InheritFromTypingModule() {
             const string code = @"
@@ -166,6 +159,18 @@ def method(self):
             analysis.Diagnostics.Should().BeEmpty();
         }
 
+        [TestMethod, Priority(0)]
+        public async Task InheritFromTypingModuleNamedTuple() {
+            const string code = @"
+from typing import NamedTuple
+
+class X(NamedTuple):
+    y: str
+";
+            var analysis = await GetAnalysisAsync(code);
+            analysis.Diagnostics.Should().BeEmpty();
+        }
+
         [TestMethod, Priority(0)]
         public async Task InheritFromOtherModule() {
             var module1Code = @"
