PY-30762: Rename param usages when fixture (to which param has reference) is renamed

Param usage has reference to PyNamedParam.
                    PyNamedParam has reference to fixture.

                    When we rename fixture, PyNamedParam is also renamed because
                    PyNamedParam#isReferenceTo(Fixture) == true, but ParamUsage#isReferenceTo(Fixture) is not.

                    We use EP to fix it.

python/src/META-INF/python-core-common.xml

@@ -650,6 +650,7 @@
   </extensions>
 
   <extensionPoints>
+    <extensionPoint qualifiedName="Pythonid.pyReferenceCustomTargetChecker" interface="com.jetbrains.python.psi.impl.references.PyReferenceCustomTargetChecker"/>
     <extensionPoint qualifiedName="Pythonid.pyTestFixtureExtension" interface="com.jetbrains.python.testing.pyTestFixtures.PyTestFixtureExtension"/>
     <extensionPoint qualifiedName="Pythonid.pyTestConfigurationSelector"  interface="com.jetbrains.python.testing.PyTestConfigurationSelector"/>
     <extensionPoint qualifiedName="Pythonid.pythonDocumentationQuickInfoProvider" interface="com.jetbrains.python.documentation.PythonDocumentationQuickInfoProvider"/>
@@ -703,6 +704,7 @@
   </extensionPoints>
 
   <extensions defaultExtensionNs="Pythonid">
+    <pyReferenceCustomTargetChecker implementation="com.jetbrains.python.testing.pyTestFixtures.PyTestFixtureTargetChecker"/>
     <pySuperMethodsSearch implementation="com.jetbrains.python.psi.search.PySuperMethodsSearchExecutor"/>
     <pyClassInheritorsSearch implementation="com.jetbrains.python.psi.search.PyClassInheritorsSearchExecutor"/>
     <pyOverridingMethodsSearch implementation="com.jetbrains.python.psi.search.PyOverridingMethodsSearchExecutor"/>

python/src/com/jetbrains/python/psi/impl/references/PyReferenceCustomTargetChecker.kt

@@ -0,0 +1,18 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.jetbrains.python.psi.impl.references
+
+import com.intellij.openapi.extensions.ExtensionPointName
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiReference
+
+/**
+ * EP to check if some reference points to some element
+ */
+interface PyReferenceCustomTargetChecker {
+  companion object {
+    val EP_NAME = ExtensionPointName.create<PyReferenceCustomTargetChecker>("Pythonid.pyReferenceCustomTargetChecker")
+    fun isReferenceTo(reference: PsiReference, to: PsiElement) = EP_NAME.extensions.firstOrNull { it.isReferenceTo(reference, to) } != null
+  }
+
+  fun isReferenceTo(reference: PsiReference, to: PsiElement): Boolean
+}

python/src/com/jetbrains/python/psi/impl/references/PyReferenceImpl.java

@@ -570,7 +570,8 @@ public class PyReferenceImpl implements PsiReferenceEx, PsiPolyVariantReference
         }
       }
     }
-    return false;
+
+    return PyReferenceCustomTargetChecker.Companion.isReferenceTo(this, element);
   }
 
   private boolean resolvesToSameLocal(PsiElement element, String elementName, ScopeOwner ourScopeOwner, ScopeOwner theirScopeOwner) {

python/src/com/jetbrains/python/testing/pyTestFixtures/PyTestFixture.kt

@@ -41,9 +41,9 @@ internal fun getFixture(element: PyNamedParameter, typeEvalContext: TypeEvalCont
 fun PyNamedParameter.isFixture(typeEvalContext: TypeEvalContext) = getFixture(this, typeEvalContext) != null
 
 /**
- * @return Boolean is function decorated as fixture
+ * @return Boolean is function decorated as fixture or marked so by EP
  */
-internal fun PyFunction.isFixture() = decoratorList?.findDecorator(decoratorName) != null
+internal fun PyFunction.isFixture() = decoratorList?.findDecorator(decoratorName) != null || isCustomFixture()
 
 
 /**
@@ -92,7 +92,7 @@ private val pyTestName = PyTestFrameworkService.getSdkReadableNameByFramework(Py
 internal fun getFixtures(module: Module, forWhat: PyFunction, typeEvalContext: TypeEvalContext): List<PyTestFixture> {
   // Fixtures could be used only by test functions or other fixtures.
   val fixture = forWhat.isFixture()
-  val pyTestEnabled = TestRunnerService.getInstance(module).projectConfiguration == pyTestName
+  val pyTestEnabled = isPyTestEnabled(module)
   return if (
     fixture ||
     (pyTestEnabled && isTestElement(forWhat, ThreeState.NO, typeEvalContext)) ||
@@ -107,4 +107,7 @@ internal fun getFixtures(module: Module, forWhat: PyFunction, typeEvalContext: T
   else emptyList()
 }
 
+internal fun isPyTestEnabled(module: Module) =
+  TestRunnerService.getInstance(module).projectConfiguration == pyTestName
+
 

python/src/com/jetbrains/python/testing/pyTestFixtures/PyTestFixtureInspectionExtension.kt

@@ -14,6 +14,5 @@ object PyTestFixtureInspectionExtension : PyInspectionExtension() {
   override fun ignoreUnused(local: PsiElement, evalContext: TypeEvalContext) =
     local is PyNamedParameter && local.isFixture(evalContext)
 
-  override fun ignoreShadowed(element: PsiElement) = element is PyFunction
-                                                     && (element.isFixture() || element.isCustomFixture())
+  override fun ignoreShadowed(element: PsiElement) = element is PyFunction && element.isFixture()
 }

python/src/com/jetbrains/python/testing/pyTestFixtures/PyTestFixtureReferenceContributor.kt

@@ -13,7 +13,7 @@ import com.jetbrains.python.psi.types.PyType
 import com.jetbrains.python.psi.types.PyTypeProviderBase
 import com.jetbrains.python.psi.types.TypeEvalContext
 
-private class PyTextFixtureReference(namedParameter: PyNamedParameter, fixture: PyTestFixture) : BaseReference(namedParameter) {
+class PyTestFixtureReference(namedParameter: PyNamedParameter, fixture: PyTestFixture) : BaseReference(namedParameter) {
   private val functionRef = SmartPointerManager.createPointer(fixture.function)
   private val resolveRef = SmartPointerManager.createPointer(fixture.resolveTarget)
 
@@ -33,7 +33,7 @@ private class PyTextFixtureReference(namedParameter: PyNamedParameter, fixture:
 object PyTextFixtureTypeProvider : PyTypeProviderBase() {
   override fun getReferenceType(referenceTarget: PsiElement, context: TypeEvalContext, anchor: PsiElement?): Ref<PyType>? {
     val param = referenceTarget as? PyNamedParameter ?: return null
-    val fixtureFunc = param.references.filterIsInstance(PyTextFixtureReference::class.java).firstOrNull()?.getFunction() ?: return null
+    val fixtureFunc = param.references.filterIsInstance(PyTestFixtureReference::class.java).firstOrNull()?.getFunction() ?: return null
     return context.getReturnType(fixtureFunc)?.let { Ref(it) }
 
   }
@@ -43,7 +43,7 @@ private object PyTestReferenceProvider : PsiReferenceProvider() {
   override fun getReferencesByElement(element: PsiElement, context: ProcessingContext): Array<PsiReference> {
     val namedParam = element as? PyNamedParameter ?: return emptyArray()
     val fixture = getFixture(namedParam, TypeEvalContext.codeAnalysis(element.project, element.containingFile)) ?: return emptyArray()
-    return arrayOf(PyTextFixtureReference(namedParam, fixture))
+    return arrayOf(PyTestFixtureReference(namedParam, fixture))
   }
 }
 

python/src/com/jetbrains/python/testing/pyTestFixtures/PyTestFixtureTargetChecker.kt

@@ -0,0 +1,26 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.jetbrains.python.testing.pyTestFixtures
+
+import com.intellij.openapi.module.ModuleUtilCore
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiReference
+import com.jetbrains.python.psi.PyFunction
+import com.jetbrains.python.psi.PyNamedParameter
+import com.jetbrains.python.psi.impl.references.PyReferenceCustomTargetChecker
+
+class PyTestFixtureTargetChecker : PyReferenceCustomTargetChecker {
+  override fun isReferenceTo(reference: PsiReference, to: PsiElement): Boolean {
+    val function = to as? PyFunction ?: return false
+    val module = ModuleUtilCore.findModuleForPsiElement(to) ?: return false
+
+    // reference is reference from param usage to param
+    // param has reference to fixture
+
+    if (function.isFixture() && isPyTestEnabled(module)) {
+      val parameter = reference.resolve() as? PyNamedParameter ?: return false
+      val ref = parameter.references.filterIsInstance<PyTestFixtureReference>().firstOrNull() ?: return false
+      return ref.isReferenceTo(to)
+    }
+    return false
+  }
+}