Show generic types in PEP 484 notation (PY-16889)

In particular, show unresolved refernces in generic bounds as Any.
We used to ignore these unresolved types which resulted in
incomprehensible warning messages.

python/src/com/jetbrains/python/psi/types/PyGenericType.java

@@ -15,8 +15,11 @@
  */
 package com.jetbrains.python.psi.types;
 
+import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.PsiElement;
+import com.intellij.util.Function;
 import com.intellij.util.ProcessingContext;
+import com.jetbrains.python.PyNames;
 import com.jetbrains.python.psi.AccessDirection;
 import com.jetbrains.python.psi.PyExpression;
 import com.jetbrains.python.psi.resolve.PyResolveContext;
@@ -55,7 +58,19 @@ public class PyGenericType implements PyType {
   @NotNull
   @Override
   public String getName() {
-    return myBound != null ? myName + " <= " + myBound.getName() : myName;
+    if (myBound instanceof PyUnionType) {
+      final PyUnionType bounds = (PyUnionType)myBound;
+      final String boundsString = StringUtil.join(bounds.getMembers(), new Function<PyType, String>() {
+        @Override
+        public String fun(PyType type) {
+          return type != null ? type.getName() : PyNames.UNKNOWN_TYPE;
+        }
+      }, ", ");
+      return "TypeVar('" + myName + "', " + boundsString + ")";
+    }
+    else {
+      return "TypeVar('" + myName + "')";
+    }
   }
 
   @Override

python/testData/inspections/PyTypeCheckerInspection/BoundedGeneric.py

@@ -8,5 +8,5 @@ def test():
 
     x = f(10)
     y = f('foo')
-    z = f(<warning descr="Expected type 'T <= int | str', got 'list' instead">[]</warning>)
+    z = f(<warning descr="Expected type 'TypeVar('T', int, str)', got 'list' instead">[]</warning>)
     return x + <warning descr="Expected type 'Number', got 'str' instead">y</warning>

python/testData/inspections/PyTypeCheckerInspection/GenericUserClasses.py

@@ -21,4 +21,4 @@ class User1(object):
 c = User1(10)
 print(c.get() + <warning descr="Expected type 'Number', got 'str' instead">'foo'</warning>)
 c.put(14)
-c.put(<weak_warning descr="Expected type 'int' (matched generic type 'T'), got 'str' instead">'foo'</weak_warning>)
+c.put(<weak_warning descr="Expected type 'int' (matched generic type 'TypeVar('T')'), got 'str' instead">'foo'</weak_warning>)

python/testData/inspections/PyTypeCheckerInspection/GenericUserFunctions.py

@@ -40,7 +40,7 @@ def test():
     print(result)
     print(result + <warning descr="Expected type 'Number', got 'str' instead">'foo'</warning>)
 
-    f2(1, <weak_warning descr="Expected type 'list[int]' (matched generic type 'list[T]'), got 'list[str]' instead">['foo']</weak_warning>, 'bar')
+    f2(1, <weak_warning descr="Expected type 'list[int]' (matched generic type 'list[TypeVar('T')]'), got 'list[str]' instead">['foo']</weak_warning>, 'bar')
 
     result = f3(1, 'foo', True)
     f4(<warning descr="Expected type 'Tuple[bool, int, str]', got 'Tuple[int, str, bool]' instead">result</warning>)

python/testData/inspections/PyTypeCheckerInspection/SecondFormIter.py

@@ -7,7 +7,7 @@ def test_second_form():
 
 
 def test_second_form_fail():
-    for chunk in iter(<weak_warning descr="Expected type 'Union[Iterable, () -> object]' (matched generic type 'Union[Iterable[T], () -> object]'), got 'int' instead">10</weak_warning>, ''):
+    for chunk in iter(<weak_warning descr="Expected type 'Union[Iterable, () -> object]' (matched generic type 'Union[Iterable[TypeVar('T')], () -> object]'), got 'int' instead">10</weak_warning>, ''):
         pass
 
 

python/testData/inspections/PyTypeCheckerInspection/TypingTypeVarWithUnresolvedBound.py

@@ -0,0 +1,11 @@
+from typing import TypeVar
+
+
+T = TypeVar('T', int, unresolved)
+
+
+def calc(a: T, b: T):
+    pass
+
+
+calc('a', <weak_warning descr="Expected type 'str' (matched generic type 'TypeVar('T', int, Any)'), got 'int' instead">0</weak_warning>)

python/testData/pyi/inspections/overloads/Overloads.py

@@ -31,6 +31,6 @@ def test_stub_only_function(x):
 
 def tset_overloaded_generics(x):
     g(<warning descr="Expected type 'dict', got 'int' instead">Gen(10).get(10, 10)</warning>)
-    g(Gen(10).get(10, <weak_warning descr="Expected type 'int' (matched generic type 'T'), got 'str' instead">'foo'</weak_warning>))
-    g(Gen('foo').get(10, <weak_warning descr="Expected type 'str' (matched generic type 'T'), got 'int' instead">10</weak_warning>))
+    g(Gen(10).get(10, <weak_warning descr="Expected type 'int' (matched generic type 'TypeVar('T')'), got 'str' instead">'foo'</weak_warning>))
+    g(Gen('foo').get(10, <weak_warning descr="Expected type 'str' (matched generic type 'TypeVar('T')'), got 'int' instead">10</weak_warning>))
     g(<warning descr="Expected type 'dict', got 'str' instead">Gen('foo').get(10, 'foo')</warning>)

python/testSrc/com/jetbrains/python/PyTypeParserTest.java

@@ -137,7 +137,7 @@ public class PyTypeParserTest extends PyTestCase {
     final PyType type = PyTypeParser.getTypeByName(myFixture.getFile(), "T");
     assertNotNull(type);
     assertInstanceOf(type, PyGenericType.class);
-    assertEquals("T", type.getName());
+    assertEquals("TypeVar('T')", type.getName());
   }
 
   // PY-4223
@@ -251,7 +251,7 @@ public class PyTypeParserTest extends PyTestCase {
     assertEquals("int", type0.getName());
     final PyType type1 = parameterTypes.get(1).getType(context);
     assertNotNull(type1);
-    assertEquals("T", type1.getName());
+    assertEquals("TypeVar('T')", type1.getName());
   }
 
   public void testCallableWithoutArgs() {

python/testSrc/com/jetbrains/python/PyTypingTest.java

@@ -151,7 +151,7 @@ public class PyTypingTest extends PyTestCase {
   }
 
   public void testGenericType() {
-    doTest("A",
+    doTest("TypeVar('A')",
            "from typing import TypeVar\n" +
            "\n" +
            "T = TypeVar('A')\n" +
@@ -161,7 +161,7 @@ public class PyTypingTest extends PyTestCase {
   }
 
   public void testGenericBoundedType() {
-    doTest("T <= int | str",
+    doTest("TypeVar('T', int, str)",
            "from typing import TypeVar\n" +
            "\n" +
            "T = TypeVar('T', int, str)\n" +

python/testSrc/com/jetbrains/python/inspections/Py3TypeCheckerInspectionTest.java

@@ -78,4 +78,9 @@ public class Py3TypeCheckerInspectionTest extends PyTestCase {
   public void testTypingListSubscriptionExpression() {
     doTest();
   }
+
+  // PY-16855
+  public void testTypingTypeVarWithUnresolvedBound() {
+    doTest();
+  }
 }