PY-15605 Add test case for the issue, though it has been fixed in the platform already

python/testData/reparse/SimilarDecorators.py

@@ -0,0 +1,6 @@
+@decorator('a')
+def foo():
+    pass
+
+@decorator('b')
+de<caret>

python/testSrc/com/jetbrains/python/PythonReparseTest.java

@@ -0,0 +1,28 @@
+package com.jetbrains.python;
+
+import com.intellij.psi.PsiDocumentManager;
+import com.intellij.psi.impl.DebugUtil;
+import com.jetbrains.python.fixtures.PyTestCase;
+
+/**
+ * Analogous to CythonReparseTest.
+ *
+ * @author Mikhail Golubev
+ */
+public class PythonReparseTest extends PyTestCase {
+  private void doTest(final String typedText) throws InterruptedException {
+    final String testName = getTestName(false);
+    myFixture.configureByFile("reparse/" + testName + ".py");
+    myFixture.type(typedText);
+    PsiDocumentManager.getInstance(myFixture.getProject()).commitAllDocuments();
+    final String actualPsiText = DebugUtil.psiToString(myFixture.getFile(), false);
+    myFixture.configureByText(testName + ".py", myFixture.getEditor().getDocument().getText());
+    final String expectedPsiText = DebugUtil.psiToString(myFixture.getFile(), false);
+    assertEquals(expectedPsiText, actualPsiText);
+  }
+
+  // PY-15605
+  public void testSimilarDecorators() throws InterruptedException {
+    doTest("f");
+  }
+}