refactor: Evaluate page_size in __post_init__ instead of get_page_size()

This change evaluates the interpolated page_size once during initialization
rather than on every get_page_size() call, matching the pattern used by
PageIncrement. This is more efficient and catches configuration errors
earlier at initialization time.

Co-Authored-By: alfredo.garcia@airbyte.io <freddy.garcia7.fg@gmail.com>

Author: devin-ai-integration[bot]

airbyte_cdk/sources/declarative/requesters/paginators/strategies/cursor_pagination_strategy.py

@@ -54,13 +54,13 @@ def __post_init__(self, parameters: Mapping[str, Any]) -> None:
         else:
             self._stop_condition = self.stop_condition
 
-        page_size = str(self.page_size) if isinstance(self.page_size, int) else self.page_size
-        if page_size:
-            self._page_size: Optional[InterpolatedString] = InterpolatedString(
-                page_size, parameters=parameters
-            )
+        if isinstance(self.page_size, int) or (self.page_size is None):
+            self._page_size = self.page_size
         else:
-            self._page_size = None
+            page_size = InterpolatedString(self.page_size, parameters=parameters).eval(self.config)
+            if not isinstance(page_size, int):
+                raise Exception(f"{page_size} is of type {type(page_size)}. Expected {int}")
+            self._page_size = page_size
 
     @property
     def initial_token(self) -> Optional[Any]:
@@ -103,10 +103,4 @@ def next_page_token(
         return token if token else None
 
     def get_page_size(self) -> Optional[int]:
-        if self._page_size:
-            page_size = self._page_size.eval(self.config)
-            if not isinstance(page_size, int):
-                raise Exception(f"{page_size} is of type {type(page_size)}. Expected {int}")
-            return page_size
-        else:
-            return None
+        return self._page_size

unit_tests/sources/declarative/requesters/paginators/test_cursor_pagination_strategy.py

@@ -144,12 +144,11 @@ def test_interpolated_page_size(page_size_input, config, expected_page_size):
 
 
 def test_interpolated_page_size_raises_on_non_integer():
-    """Test that get_page_size raises an exception when interpolation resolves to a non-integer."""
-    strategy = CursorPaginationStrategy(
-        page_size="{{ config['page_size'] }}",
-        cursor_value="token",
-        config={"page_size": "invalid"},
-        parameters={},
-    )
+    """Test that initialization raises an exception when interpolation resolves to a non-integer."""
     with pytest.raises(Exception, match="is of type .* Expected"):
-        strategy.get_page_size()
+        CursorPaginationStrategy(
+            page_size="{{ config['page_size'] }}",
+            cursor_value="token",
+            config={"page_size": "invalid"},
+            parameters={},
+        )