Harden paginated page param helper validation

Co-authored-by: Shri Sukhani <shrisukhani@users.noreply.github.com>

Author: cursoragent

hyperbrowser/client/managers/page_params_utils.py

@@ -1,4 +1,7 @@
-from typing import Type, TypeVar
+from typing import Type, TypeVar, cast
+
+from hyperbrowser.exceptions import HyperbrowserError
+from hyperbrowser.type_utils import is_plain_int
 
 DEFAULT_PAGE_BATCH_SIZE = 100
 
@@ -11,5 +14,20 @@ def build_page_batch_params(
     page: int,
     batch_size: int = DEFAULT_PAGE_BATCH_SIZE,
 ) -> T:
-    params_model_obj = params_model
-    return params_model_obj(page=page, batch_size=batch_size)  # type: ignore[call-arg]
+    if not is_plain_int(page):
+        raise HyperbrowserError("page must be a plain integer")
+    if page <= 0:
+        raise HyperbrowserError("page must be a positive integer")
+    if not is_plain_int(batch_size):
+        raise HyperbrowserError("batch_size must be a plain integer")
+    if batch_size <= 0:
+        raise HyperbrowserError("batch_size must be a positive integer")
+    try:
+        return cast(T, params_model(page=page, batch_size=batch_size))
+    except HyperbrowserError:
+        raise
+    except Exception as exc:
+        raise HyperbrowserError(
+            "Failed to build paginated page params",
+            original_error=exc,
+        ) from exc

tests/test_page_params_utils.py

@@ -1,7 +1,10 @@
+import pytest
+
 from hyperbrowser.client.managers.page_params_utils import (
     DEFAULT_PAGE_BATCH_SIZE,
     build_page_batch_params,
 )
+from hyperbrowser.exceptions import HyperbrowserError
 from hyperbrowser.models.crawl import GetCrawlJobParams
 from hyperbrowser.models.scrape import GetBatchScrapeJobParams
 
@@ -20,3 +23,54 @@ def test_build_page_batch_params_accepts_custom_batch_size():
     assert isinstance(params, GetCrawlJobParams)
     assert params.page == 2
     assert params.batch_size == 25
+
+
+def test_build_page_batch_params_rejects_non_plain_int_page():
+    with pytest.raises(HyperbrowserError, match="page must be a plain integer"):
+        build_page_batch_params(GetBatchScrapeJobParams, page=True)  # type: ignore[arg-type]
+
+
+def test_build_page_batch_params_rejects_non_positive_page():
+    with pytest.raises(HyperbrowserError, match="page must be a positive integer"):
+        build_page_batch_params(GetBatchScrapeJobParams, page=0)
+
+
+def test_build_page_batch_params_rejects_non_plain_int_batch_size():
+    class _IntSubclass(int):
+        pass
+
+    with pytest.raises(HyperbrowserError, match="batch_size must be a plain integer"):
+        build_page_batch_params(
+            GetBatchScrapeJobParams,
+            page=1,
+            batch_size=_IntSubclass(10),  # type: ignore[arg-type]
+        )
+
+
+def test_build_page_batch_params_rejects_non_positive_batch_size():
+    with pytest.raises(HyperbrowserError, match="batch_size must be a positive integer"):
+        build_page_batch_params(GetBatchScrapeJobParams, page=1, batch_size=0)
+
+
+def test_build_page_batch_params_wraps_runtime_constructor_errors():
+    class _BrokenParams:
+        def __init__(self, *, page, batch_size):  # noqa: ARG002
+            raise RuntimeError("boom")
+
+    with pytest.raises(
+        HyperbrowserError, match="Failed to build paginated page params"
+    ) as exc_info:
+        build_page_batch_params(_BrokenParams, page=1)
+
+    assert isinstance(exc_info.value.original_error, RuntimeError)
+
+
+def test_build_page_batch_params_preserves_hyperbrowser_errors():
+    class _BrokenParams:
+        def __init__(self, *, page, batch_size):  # noqa: ARG002
+            raise HyperbrowserError("custom failure")
+
+    with pytest.raises(HyperbrowserError, match="custom failure") as exc_info:
+        build_page_batch_params(_BrokenParams, page=1)
+
+    assert exc_info.value.original_error is None