Filter out fake elements from typeshed builtins (PY-22508)

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

@@ -19,6 +19,7 @@ import com.intellij.psi.FileViewProvider
 import com.jetbrains.python.PythonFileType
 import com.jetbrains.python.psi.LanguageLevel
 import com.jetbrains.python.psi.PyImportElement
+import com.jetbrains.python.psi.impl.PyBuiltinCache
 import com.jetbrains.python.psi.impl.PyFileImpl
 import com.jetbrains.python.psi.resolve.ImportedResolveResult
 import com.jetbrains.python.psi.resolve.RatedResolveResult
@@ -29,11 +30,13 @@ import com.jetbrains.python.psi.resolve.RatedResolveResult
 class PyiFile(viewProvider: FileViewProvider) : PyFileImpl(viewProvider, PyiLanguageDialect.getInstance()) {
   override fun getFileType(): PythonFileType = PyiFileType.INSTANCE
 
-  override fun toString(): String = "PyiFile:" + name
+  override fun toString(): String = "PyiFile:$name"
 
   override fun getLanguageLevel(): LanguageLevel = LanguageLevel.PYTHON37
 
   override fun multiResolveName(name: String, exported: Boolean): List<RatedResolveResult> {
+    if (name == "function" && PyBuiltinCache.getInstance(this).builtinsFile == this) return emptyList()
+
     val baseResults = super.multiResolveName(name, exported)
     return if (exported)
       baseResults

python/testData/inspections/PyShadowingBuiltinsInspection/test.py

@@ -48,3 +48,9 @@ def test_builtin_qualified_name():
 def test_builtin_class_attribute():
     class C:
         id = 1
+
+
+# PY-22508
+def test_fakes_from_typeshed():
+    function = 10
+    module = 10

python/testData/intentions/convertLambdaToFunction2_after.py

@@ -1,5 +1,5 @@
 def transform():
-  def function1(x):
+  def function(x):
       return x + 5
 
-  return function1
+  return function

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

@@ -764,6 +764,12 @@ public class PyUnresolvedReferencesInspectionTest extends PyInspectionTestCase {
     doTest();
   }
 
+  // PY-22508
+  public void testFakesFromTypeshed() {
+    doTestByText("print(<error descr=\"Unresolved reference 'function'\">function</error>)\n" +
+                 "print(<error descr=\"Unresolved reference 'module'\">module</error>)");
+  }
+
   @NotNull
   @Override
   protected Class<? extends PyInspection> getInspectionClass() {