Support incomplete stubs by changing language level to Python 3.7 (PY-22868)

python/src/com/jetbrains/python/pyi/PyiFile.kt

@@ -30,7 +30,7 @@ class PyiFile(viewProvider: FileViewProvider) : PyFileImpl(viewProvider, PyiLang
 
   override fun toString() = "PyiFile:" + name
 
-  override fun getLanguageLevel() = LanguageLevel.PYTHON36
+  override fun getLanguageLevel() = LanguageLevel.PYTHON37
 
   override fun multiResolveName(name: String, exported: Boolean): List<RatedResolveResult> {
     val baseResults = super.multiResolveName(name, exported)

python/testData/inspections/PyUnresolvedReferencesInspection/StubWithGetAttr/a.py

@@ -0,0 +1,8 @@
+from complete import a
+from complete import b
+from complete import <error descr="Cannot find reference 'e' in 'complete.pyi'">e</error>
+
+from incomplete import c
+from incomplete import d
+
+print(a, b, c, d, e)

python/testData/inspections/PyUnresolvedReferencesInspection/StubWithGetAttr/complete.py

@@ -0,0 +1,5 @@
+def a():
+    return 1
+
+def b():
+    return ""

python/testData/inspections/PyUnresolvedReferencesInspection/StubWithGetAttr/complete.pyi

@@ -0,0 +1,2 @@
+def a() -> int: ...
+def b() -> str: ...

python/testData/inspections/PyUnresolvedReferencesInspection/StubWithGetAttr/incomplete.py

@@ -0,0 +1,5 @@
+def c():
+    return 1
+
+def d():
+    return ""

python/testData/inspections/PyUnresolvedReferencesInspection/StubWithGetAttr/incomplete.pyi

@@ -0,0 +1,6 @@
+from typing import Any
+
+
+def c() -> int: ...
+
+def __getattr__(name) -> Any: ...

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

@@ -665,6 +665,11 @@ public class PyUnresolvedReferencesInspectionTest extends PyInspectionTestCase {
     runWithLanguageLevel(LanguageLevel.PYTHON37, this::doMultiFileTest);
   }
 
+  // PY-22868
+  public void testStubWithGetAttr() {
+    doMultiFileTest();
+  }
+
   @NotNull
   @Override
   protected Class<? extends PyInspection> getInspectionClass() {

python/testSrc/com/jetbrains/python/pyi/PyiParsingTest.java

@@ -17,7 +17,10 @@ package com.jetbrains.python.pyi;
 
 import com.intellij.testFramework.ParsingTestCase;
 import com.intellij.testFramework.TestDataPath;
-import com.jetbrains.python.*;
+import com.jetbrains.python.PythonDialectsTokenSetContributor;
+import com.jetbrains.python.PythonDialectsTokenSetProvider;
+import com.jetbrains.python.PythonTestUtil;
+import com.jetbrains.python.PythonTokenSetContributor;
 import com.jetbrains.python.psi.LanguageLevel;
 
 /**
@@ -50,6 +53,6 @@ public class PyiParsingTest extends ParsingTestCase {
     doTest();
     assertInstanceOf(myFile, PyiFile.class);
     final PyiFile pyiFile = (PyiFile)myFile;
-    assertEquals(LanguageLevel.PYTHON36, pyiFile.getLanguageLevel());
+    assertEquals(LanguageLevel.PYTHON37, pyiFile.getLanguageLevel());
   }
 }