PY-31053: @fixture is not supported (only @pytest.fixture)

We must support both styles

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

@@ -8,10 +8,7 @@ import com.intellij.psi.stubs.StubIndex
 import com.intellij.psi.util.PsiTreeUtil
 import com.intellij.util.ThreeState
 import com.jetbrains.python.PyNames
-import com.jetbrains.python.psi.PyDecorator
-import com.jetbrains.python.psi.PyElement
-import com.jetbrains.python.psi.PyFunction
-import com.jetbrains.python.psi.PyNamedParameter
+import com.jetbrains.python.psi.*
 import com.jetbrains.python.psi.impl.PyEvaluator
 import com.jetbrains.python.psi.stubs.PyDecoratorStubIndex
 import com.jetbrains.python.psi.types.TypeEvalContext
@@ -19,7 +16,9 @@ import com.jetbrains.python.testing.PyTestFrameworkService
 import com.jetbrains.python.testing.TestRunnerService
 import com.jetbrains.python.testing.isTestElement
 
-private const val decoratorName: String = "pytest.fixture"
+private val decoratorNames = arrayOf("pytest.fixture", "fixture")
+
+private fun PyDecoratorList.hasDecorator(vararg names: String) = names.map { findDecorator(it) }.firstOrNull() != null ?: false
 
 /**
  * If named parameter has fixture -- return it
@@ -35,10 +34,11 @@ internal fun getFixture(element: PyNamedParameter, typeEvalContext: TypeEvalCont
  */
 fun PyNamedParameter.isFixture(typeEvalContext: TypeEvalContext) = getFixture(this, typeEvalContext) != null
 
+
 /**
  * @return Boolean is function decorated as fixture or marked so by EP
  */
-internal fun PyFunction.isFixture() = decoratorList?.findDecorator(decoratorName) != null || isCustomFixture()
+internal fun PyFunction.isFixture() = decoratorList?.hasDecorator(*decoratorNames) ?: false || isCustomFixture()
 
 
 /**
@@ -49,11 +49,13 @@ internal fun PyFunction.isFixture() = decoratorList?.findDecorator(decoratorName
 data class PyTestFixture(val function: PyFunction? = null, val resolveTarget: PyElement? = function, val name: String)
 
 
-fun findDecoratorsByName(module: Module, name: String): Iterable<PyDecorator> =
-  StubIndex.getElements(PyDecoratorStubIndex.KEY, name, module.project,
-                        GlobalSearchScope.union(
-                          arrayOf(module.moduleContentScope, GlobalSearchScope.moduleRuntimeScope(module, true))),
-                        PyDecorator::class.java)
+fun findDecoratorsByName(module: Module, vararg names: String): Iterable<PyDecorator> =
+  names.map { name ->
+    StubIndex.getElements(PyDecoratorStubIndex.KEY, name, module.project,
+                          GlobalSearchScope.union(
+                            arrayOf(module.moduleContentScope, GlobalSearchScope.moduleRuntimeScope(module, true))),
+                          PyDecorator::class.java)
+  }.flatten()
 
 
 private fun createFixture(decorator: PyDecorator): PyTestFixture? {
@@ -88,7 +90,7 @@ internal fun getFixtures(module: Module, forWhat: PyFunction, typeEvalContext: T
     forWhat.isSubjectForFixture()
   ) {
     //Fixtures
-    (findDecoratorsByName(module, decoratorName)
+    (findDecoratorsByName(module, *decoratorNames)
        .mapNotNull { createFixture(it) }
      + getCustomFixtures(typeEvalContext, forWhat))
       .filterNot { fixture && it.name == forWhat.name }.toList()  // Do not suggest fixture for itself