From 61b55f5a7172756fa36eff70c25849c68907abb9 Mon Sep 17 00:00:00 2001
From: "evgeny.bovykin" <evgeny.bovykin@jetbrains.com>
Date: Thu, 25 Sep 2025 13:48:01 +0200
Subject: [PATCH] PY-84289 Compute `getStringBasedType` with
 `doPreventingRecursion` to avoid repeating calculations

GitOrigin-RevId: a548f05bea971f6b3e3acdb1f1bc7898d3411d5e
---
 .../typing/PyTypingTypeProvider.java          |  6 ++--
 .../a.py                                      |  1 +
 .../main.py                                   | 35 +++++++++++++++++++
 .../PyTypeHintsInspectionTest.java            | 13 +++++++
 4 files changed, 53 insertions(+), 2 deletions(-)
 create mode 100644 python/testData/inspections/PyTypeHintsInspection/ExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName/a.py
 create mode 100644 python/testData/inspections/PyTypeHintsInspection/ExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName/main.py

diff --git a/python/python-psi-impl/src/com/jetbrains/python/codeInsight/typing/PyTypingTypeProvider.java b/python/python-psi-impl/src/com/jetbrains/python/codeInsight/typing/PyTypingTypeProvider.java
index f72268c95d61..719b12704723 100644
--- a/python/python-psi-impl/src/com/jetbrains/python/codeInsight/typing/PyTypingTypeProvider.java
+++ b/python/python-psi-impl/src/com/jetbrains/python/codeInsight/typing/PyTypingTypeProvider.java
@@ -1322,8 +1322,10 @@ public final class PyTypingTypeProvider extends PyTypeProviderWithCustomContext<
   }
 
   private static @Nullable Ref<PyType> getStringBasedType(@NotNull String contents, @NotNull PsiElement anchor, @NotNull Context context) {
-    final PyExpression expr = toExpression(contents, anchor);
-    return expr != null ? getType(expr, context) : null;
+    return doPreventingRecursion(Pair.create(anchor, contents), true, () -> {
+      final PyExpression expr = toExpression(contents, anchor);
+      return expr != null ? getType(expr, context) : null;
+    });
   }
 
   private static @Nullable PyType getStringLiteralType(@NotNull PsiElement element, @NotNull Context context) {
diff --git a/python/testData/inspections/PyTypeHintsInspection/ExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName/a.py b/python/testData/inspections/PyTypeHintsInspection/ExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName/a.py
new file mode 100644
index 000000000000..013cf035b444
--- /dev/null
+++ b/python/testData/inspections/PyTypeHintsInspection/ExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName/a.py
@@ -0,0 +1 @@
+config_response = {}
\ No newline at end of file
diff --git a/python/testData/inspections/PyTypeHintsInspection/ExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName/main.py b/python/testData/inspections/PyTypeHintsInspection/ExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName/main.py
new file mode 100644
index 000000000000..77d82cc1be43
--- /dev/null
+++ b/python/testData/inspections/PyTypeHintsInspection/ExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName/main.py
@@ -0,0 +1,35 @@
+from a import config_response
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
+
+config_response = {}
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
+
+config_response = {}
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
+
+config_response = {}
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
+
+config_response = {}
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
+
+config_response = {}
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
+
+config_response = {}
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
+
+config_response = {}
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
+
+config_response = {}
+config_map = config_response["spec"]["config_map"]
+kafka_consumer_key = config_map["component.job.static.job2"]["spec.plugin.kafka.connectivity.in"]
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/inspections/PyTypeHintsInspectionTest.java b/python/testSrc/com/jetbrains/python/inspections/PyTypeHintsInspectionTest.java
index 25ed7b4821ad..ac133d6545d5 100644
--- a/python/testSrc/com/jetbrains/python/inspections/PyTypeHintsInspectionTest.java
+++ b/python/testSrc/com/jetbrains/python/inspections/PyTypeHintsInspectionTest.java
@@ -3156,6 +3156,19 @@ public class PyTypeHintsInspectionTest extends PyInspectionTestCase {
     doMultiFileTest();
   }
 
+
+  // PY-84289
+  public void testExponentialAnalysisTimeWhenMapLookupKeyEqualsVariableName() {
+    long before = System.currentTimeMillis();
+    doMultiFileTest("main.py");
+    long after = System.currentTimeMillis();
+    long diff = after - before;
+    // junit3 doesn't support timeouts out of the box
+    if (diff > 5000) {
+      fail("Took too long to analyze main.py: " + diff + " ms");
+    }
+  }
+
   @NotNull
   @Override
   protected Class<? extends PyInspection> getInspectionClass() {