Handling some more cases for TypeVar bound

src/Analysis/Ast/Impl/Extensions/ArgumentSetExtensions.cs

@@ -32,8 +32,11 @@ public static IReadOnlyList<KeyValuePair<string, T>> Arguments<T>(this IArgument
         public static T Argument<T>(this IArgumentSet args, int index) where T : class
             => args.Arguments[index].Value as T;
 
+        public static IArgument Argument(this IArgumentSet args, string name, bool excludeDefault = true) 
+            => args.Arguments.FirstOrDefault(a => name.Equals(a.Name) && !(excludeDefault &&a.ValueIsDefault));
+
         public static T GetArgumentValue<T>(this IArgumentSet args, string name, bool excludeDefault = true) where T : class {
-            var value = args.Arguments.FirstOrDefault(a => name.Equals(a.Name) && !(excludeDefault && a.ValueIsDefault))?.Value;
+            var value = Argument(args, name, excludeDefault)?.Value;
             if (value == null && args.DictionaryArgument?.Arguments != null && args.DictionaryArgument.Arguments.TryGetValue(name, out var m)) {
                 return m as T;
             }

src/Analysis/Ast/Impl/Specializations/Typing/Types/GenericTypeParameter.cs

@@ -20,6 +20,7 @@
 using Microsoft.Python.Analysis.Types;
 using Microsoft.Python.Analysis.Utilities;
 using Microsoft.Python.Analysis.Values;
+using Microsoft.Python.Core.Diagnostics;
 using Microsoft.Python.Core.Text;
 using Microsoft.Python.Parsing;
 
@@ -103,7 +104,13 @@ private static bool TypeVarArgumentsValid(IArgumentSet argSet) {
         /// </summary>
         private static IPythonType GetBoundType(IArgumentSet argSet) {
             var eval = argSet.Eval;
-            var rawBound = argSet.GetArgumentValue<IMember>("bound");
+            var boundArg = argSet.Argument("bound");
+            // User did not pass in upper bound, bail
+            if(boundArg == default) {
+                return null;
+            }
+
+            var rawBound = boundArg.Value as IMember;
             switch (rawBound) {
                 case IPythonType t:
                     return t;
@@ -119,6 +126,7 @@ private static IPythonType GetBoundType(IArgumentSet argSet) {
         }
 
         public static IPythonType FromTypeVar(IArgumentSet argSet, IPythonModule declaringModule, IndexSpan indexSpan = default) {
+            Check.ArgumentNotNull(nameof(argSet.Eval), argSet.Eval);
             if (!TypeVarArgumentsValid(argSet)) {
                 return declaringModule.Interpreter.UnknownType;
             }

src/Analysis/Ast/Impl/Specializations/Typing/TypingModule.cs

@@ -55,7 +55,7 @@ private void SpecializeMembers() {
             o.SetParameters(new List<ParameterInfo> {
                     new ParameterInfo("name", Interpreter.GetBuiltinType(BuiltinTypeId.Str), ParameterKind.Normal, null),
                     new ParameterInfo("constraints", Interpreter.GetBuiltinType(BuiltinTypeId.Str), ParameterKind.List, null),
-                    new ParameterInfo("bound", Interpreter.GetBuiltinType(BuiltinTypeId.Str), ParameterKind.KeywordOnly, new PythonConstant(null, Interpreter.GetBuiltinType(BuiltinTypeId.NoneType))),
+                    new ParameterInfo("bound", Interpreter.GetBuiltinType(BuiltinTypeId.Type), ParameterKind.KeywordOnly, new PythonConstant(null, Interpreter.GetBuiltinType(BuiltinTypeId.NoneType))),
                     new ParameterInfo("covariant", Interpreter.GetBuiltinType(BuiltinTypeId.Bool), ParameterKind.KeywordOnly, new PythonConstant(false, Interpreter.GetBuiltinType(BuiltinTypeId.Bool))),
                     new ParameterInfo("contravariant", Interpreter.GetBuiltinType(BuiltinTypeId.Bool), ParameterKind.KeywordOnly, new PythonConstant(false, Interpreter.GetBuiltinType(BuiltinTypeId.Bool)))
             });

src/Analysis/Ast/Impl/Types/PythonFunctionOverload.cs

@@ -203,8 +203,8 @@ private IMember CreateSpecificReturnFromTypeVar(IPythonClassType selfClassType,
             }
 
             // Try getting the type from the type parameter bound
-            if (returnType.Bound != null) {
-                return returnType.Bound.CreateInstance(args);
+            if (!returnType.Bound.IsUnknown()) {
+                return new PythonInstance(returnType.Bound);
             }
 
             // Try returning the constraint

src/Analysis/Ast/Test/GenericsTests.cs

@@ -1360,6 +1360,44 @@ def get(self) -> T: ...
             analysis.Should().HaveVariable("x").OfType("A");
         }
 
+        [TestMethod, Priority(0)]
+        public async Task GenericDefaultBound() {
+            const string code = @"
+from typing import TypeVar, Generic
+from logging import Logger, getLogger
+
+T = TypeVar('T')
+
+class A: ...
+
+class Test(Generic[T]):
+    def get(self) -> T: ...
+
+x = Test().get()
+";
+            var analysis = await GetAnalysisAsync(code);
+            analysis.Should().HaveVariable("x").OfType("T");
+        }
+
+        [TestMethod, Priority(0)]
+        public async Task GenericUnknownBound() {
+            const string code = @"
+from typing import TypeVar, Generic
+from logging import Logger, getLogger
+
+T = TypeVar('T', bound='unknown_thing')
+
+class A: ...
+
+class Test(Generic[T]):
+    def get(self) -> T: ...
+
+x = Test().get()
+";
+            var analysis = await GetAnalysisAsync(code);
+            analysis.Should().HaveVariable("x").OfType("T");
+        }
+
         [TestMethod, Priority(0)]
         public async Task GenericPath() {
             const string code = @"