From 922d20f6d8280aed0a55ed4906d8053bd1258a6c Mon Sep 17 00:00:00 2001
From: Jac Fitzgerald <jac.fitzgerald@salesforce.com>
Date: Wed, 17 Jun 2026 22:06:18 -0700
Subject: [PATCH] fix: use return instead of raise StopIteration in
 QuerySet.__iter__

Per PEP 479, StopIteration raised inside a generator is converted to
RuntimeError. QuerySet.__iter__ is a generator and was raising
StopIteration to handle 400006 (invalid page number) errors, causing
RuntimeError for callers iterating endpoints that don't support
pagination past the last page.

Fixes #1786

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 tableauserverclient/server/query.py |  5 +++--
 test/test_pager.py                  | 33 +++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/tableauserverclient/server/query.py b/tableauserverclient/server/query.py
index 6027a914e..eb84248b5 100644
--- a/tableauserverclient/server/query.py
+++ b/tableauserverclient/server/query.py
@@ -84,8 +84,9 @@ def __iter__(self: Self) -> Iterator[T]:
                 if e.code == "400006":
                     # If the endpoint does not support pagination, it will end
                     # up overrunning the total number of pages. Catch the
-                    # error and break out of the loop.
-                    raise StopIteration
+                    # error and return to cleanly end the generator.
+                    # (raise StopIteration would cause RuntimeError per PEP 479)
+                    return
             if len(self._result_cache) == 0:
                 return
             yield from self._result_cache
diff --git a/test/test_pager.py b/test/test_pager.py
index 0a7ccf00a..82b79016c 100644
--- a/test/test_pager.py
+++ b/test/test_pager.py
@@ -136,3 +136,36 @@ def test_queryset_no_matches(server: TSC.Server) -> None:
         all_groups = server.groups.all()
         groups = list(all_groups)
     assert len(groups) == 0
+
+
+def test_queryset_400006_returns_cleanly() -> None:
+    """Regression test for PEP 479: 400006 must not raise RuntimeError.
+
+    Before the fix, QuerySet.__iter__ raised StopIteration which PEP 479
+    converts to RuntimeError inside a generator. This test directly exercises
+    the __iter__ method with a mock that raises 400006 on the second call.
+    """
+    from tableauserverclient.server.endpoint.exceptions import ServerResponseError
+    from tableauserverclient.server.query import QuerySet
+
+    calls = [0]
+
+    class MockEndpoint:
+        def get(self, req_options=None):
+            calls[0] += 1
+            assert calls[0] <= 10, f"get() called {calls[0]} times — infinite loop detected"
+            if calls[0] >= 2:
+                raise ServerResponseError("400006", "Bad Request", "Invalid page number", "http://test")
+            item = TSC.ProjectItem(name="Test")
+            item._id = "abc"
+            pagination = TSC.PaginationItem()
+            pagination._total_available = None  # unknown size — triggers loop
+            return [item], pagination
+
+    qs: QuerySet[TSC.ProjectItem] = QuerySet(MockEndpoint())  # type: ignore[arg-type]
+
+    # Use a generator expression to bypass list()'s __len__ optimization,
+    # which would consume the first page before __iter__ starts.
+    # Before the fix this raised: RuntimeError: generator raised StopIteration
+    results = [x for x in qs]
+    assert len(results) == 1