IDEA-CR-49176: disallow function inlining for python special methods (PY-36461)

GitOrigin-RevId: e1049aec62e8c8240a555fdf818820e797d5c9a6

python/src/com/jetbrains/python/PyBundle.properties

@@ -657,6 +657,7 @@ refactoring.inline.function.generator=Cannot inline generators
 refactoring.inline.function.async=Cannot inline async functions
 refactoring.inline.function.constructor=Cannot inline constructor calls
 refactoring.inline.function.builtin=Cannot inline builtin functions
+refactoring.inline.function.special.method=Cannot inline special methods
 refactoring.inline.function.decorator=Cannot inline functions with decorators
 refactoring.inline.function.self.referrent=Cannot inline functions that reference themselves
 refactoring.inline.function.star=Cannot inline functions with * arguments

python/src/com/jetbrains/python/refactoring/inline/PyInlineFunctionHandler.kt

@@ -37,6 +37,7 @@ class PyInlineFunctionHandler : InlineActionHandler() {
       element.isGenerator -> "refactoring.inline.function.generator"
       PyNames.INIT == element.name -> "refactoring.inline.function.constructor"
       PyBuiltinCache.getInstance(element).isBuiltin(element) -> "refactoring.inline.function.builtin"
+      isSpecialMethod(element) -> "refactoring.inline.function.special.method"
       hasDecorators(element) -> "refactoring.inline.function.decorator"
       hasReferencesToSelf(element) -> "refactoring.inline.function.self.referrent"
       hasStarArgs(element) -> "refactoring.inline.function.star"
@@ -56,6 +57,10 @@ class PyInlineFunctionHandler : InlineActionHandler() {
     }
   }
 
+  private fun isSpecialMethod(function: PyFunction): Boolean {
+    return function.containingClass != null && PyNames.getBuiltinMethods(LanguageLevel.forElement(function)).contains(function.name)
+  }
+
   private fun hasNestedFunction(function: PyFunction): Boolean = SyntaxTraverser.psiTraverser(function.statementList).traverse().any { it is PyFunction }
 
   private fun hasNonExhaustiveIfs(function: PyFunction): Boolean {

python/testData/refactoring/inlineFunction/specialMethod.py

@@ -0,0 +1,9 @@
+class Additive:
+    def __init__(self, value):
+        self.value = value
+
+    def __add__(self, other):
+        return Additive(self.value + other.value)
+
+
+Additive(1) +<caret> Additive(1)

python/testSrc/com/jetbrains/python/refactoring/PyInlineFunctionTest.kt

@@ -90,6 +90,7 @@ class PyInlineFunctionTest : PyTestCase() {
   }
   fun testConstructor() = doTestError("Cannot inline constructor calls")
   fun testBuiltin() = doTestError("Cannot inline builtin functions")
+  fun testSpecialMethod() = doTestError("Cannot inline special methods")
   fun testDecorator() = doTestError("Cannot inline functions with decorators")
   fun testRecursive() = doTestError("Cannot inline functions that reference themselves")
   fun testStar() = doTestError("Cannot inline functions with * arguments")