PY-64359 Upcast PyCollectionTypeImpl to Iterable to get its proper iterated item type

(cherry picked from commit 2366c4b215a3631d270cd69850291da38e70b2ec)

GitOrigin-RevId: 8175cdbea5ff6f05c5b1beaa0fa5fe21e03ec5cf

python/python-psi-impl/src/com/jetbrains/python/psi/types/PyCollectionTypeImpl.java

@@ -108,7 +108,16 @@ public class PyCollectionTypeImpl extends PyClassTypeImpl implements PyCollectio
 
   @Override
   public @Nullable PyType getIteratedItemType() {
-    // TODO: Select the parameter type that matches T in Iterable[T]
+    if (myElementTypes.size() >= 2) {
+      String iterableName = "typing.Iterable";
+      if (!iterableName.equals(getClassQName())) {
+        TypeEvalContext context = TypeEvalContext.codeInsightFallback(getPyClass().getProject());
+        PyType asIterable = PyTypeUtil.convertToType(this, iterableName, getPyClass(), context);
+        if (asIterable instanceof PyCollectionType collectionType) {
+          return collectionType.getIteratedItemType();
+        }
+      }
+    }
     return ContainerUtil.getFirstItem(myElementTypes);
   }
 

python/testSrc/com/jetbrains/python/Py3TypeTest.java

@@ -477,7 +477,7 @@ public class Py3TypeTest extends PyTestCase {
   }
 
   public void testYieldFromUnknownTuple() {
-    doTest("Any",
+    doTest("_T_co",
            """
              def get_tuple() -> tuple:
                  pass
@@ -487,7 +487,7 @@ public class Py3TypeTest extends PyTestCase {
   }
 
   public void testYieldFromUnknownList() {
-    doTest("Any",
+    doTest("_T_co",
            """
              def get_list() -> list:
                  pass
@@ -497,7 +497,7 @@ public class Py3TypeTest extends PyTestCase {
   }
 
   public void testYieldFromUnknownDict() {
-    doTest("Any",
+    doTest("_T_co",
            """
              def get_dict() -> dict:
                  pass
@@ -507,7 +507,7 @@ public class Py3TypeTest extends PyTestCase {
   }
 
   public void testYieldFromUnknownSet() {
-    doTest("Any",
+    doTest("_T_co",
            """
              def get_set() -> set:
                  pass

python/testSrc/com/jetbrains/python/PyTypeTest.java

@@ -1693,7 +1693,7 @@ public class PyTypeTest extends PyTestCase {
 
   // PY-20794
   public void testIterateOverPureList() {
-    doTest("Any",
+    doTest("_T_co",
            """
              l = None  # type: list
              for expr in l:
@@ -1703,7 +1703,7 @@ public class PyTypeTest extends PyTestCase {
 
   // PY-20794
   public void testIterateOverDictValueWithDefaultValue() {
-    doTest("Any",
+    doTest("Union[_T_co, Any]",
            """
              d = None  # type: dict
              for expr in d.get('field', []):
@@ -2300,7 +2300,7 @@ public class PyTypeTest extends PyTestCase {
 
   // PY-24364
   public void testReassignedParameter() {
-    doTest("(entries: Any) -> Generator[Any, Any, None]",
+    doTest("(entries: Any) -> Generator[_T_co, Any, None]",
            """
              def resort(entries):
                  entries = list(entries)

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

@@ -4255,5 +4255,13 @@ public class Py3TypeCheckerInspectionTest extends PyInspectionTestCase {
                        serial_number = property(_get_serial_number)
                    """);
   }
+
+  // PY-64359
+  public void testTupleDictValues() {
+    doTestByText("""
+                   def f(a: dict[str, int]):
+                       b: tuple[int, ...] = tuple(a.values())
+                   """);
+  }
 }