fix: read scientific notation in run_end_ceiling_ms as the CLI does

src/claude_agent_sdk/_internal/query.py

@@ -2,6 +2,7 @@
 
 import json
 import logging
+import math
 import os
 import uuid
 from collections.abc import AsyncIterable, AsyncIterator, Awaitable, Callable, Mapping
@@ -60,26 +61,47 @@
 _MAX_RUN_END_CEILING_MS = 2**31 - 1
 
 
+def _parse_ceiling_ms(raw: Any) -> int | None:
+    """Parse one millisecond spelling the CLI accepts, or ``None`` if invalid.
+
+    A plain integer is read exactly, so a very large value keeps the precision
+    a float round-trip would cost it. Anything else goes through ``float``, so
+    the scientific notation the CLI also reads (``1e6``) is honored. A value
+    that is not finite or not integral is rejected rather than truncated,
+    which keeps ``0.5`` from collapsing into the ``0`` that means no limit.
+    """
+    try:
+        return int(raw)
+    except (TypeError, ValueError):
+        pass
+    try:
+        value = float(raw)
+    except (TypeError, ValueError):
+        return None
+    if not math.isfinite(value) or value != int(value):
+        return None
+    return int(value)
+
+
 def run_end_ceiling_ms(options_env: Mapping[str, str]) -> int:
     """Read ``CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS`` as the CLI will see it.
 
     ``options_env`` (``ClaudeAgentOptions.env``) overrides the inherited
     environment, as it does for the CLI subprocess. ``0`` means no limit;
-    anything that is not a plain non-negative integer falls back to the CLI's
-    default of 10 minutes (the CLI itself also reads spellings such as
-    ``1e6``).
+    a non-negative integer is taken as written, in plain decimal or in the
+    integral scientific notation the CLI also reads (``1e6``). Anything else
+    falls back to the CLI's default of 10 minutes.
     """
     if _RUN_END_CEILING_ENV in options_env:
         raw: Any = options_env[_RUN_END_CEILING_ENV]
     else:
         raw = os.environ.get(_RUN_END_CEILING_ENV)
     if raw is None:
         return DEFAULT_RUN_END_CEILING_MS
-    try:
-        value = int(raw)
-    except (TypeError, ValueError):
+    value = _parse_ceiling_ms(raw)
+    if value is None or value < 0:
         return DEFAULT_RUN_END_CEILING_MS
-    return value if value >= 0 else DEFAULT_RUN_END_CEILING_MS
+    return value
 
 
 def _error_result_text(message: dict[str, Any]) -> str:

tests/test_query.py

@@ -1357,6 +1357,16 @@ class TestRunEndCeilingFromEnv:
             ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "soon"}, None, 600_000),
             ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "-1"}, None, 600_000),
             ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": ""}, "1234", 600_000),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "1e6"}, None, 1_000_000),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "1e2"}, None, 100),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": " 1E3 "}, None, 1_000),
+            ({}, "1e6", 1_000_000),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "-1e6"}, None, 600_000),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "1.5"}, None, 600_000),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "0.5"}, None, 600_000),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "inf"}, None, 600_000),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "nan"}, None, 600_000),
+            ({"CLAUDE_CODE_PRINT_BG_WAIT_CEILING_MS": "9" * 25}, None, int("9" * 25)),
         ],
         ids=[
             "default",
@@ -1367,6 +1377,16 @@ class TestRunEndCeilingFromEnv:
             "not_a_number",
             "negative",
             "empty_option_wins",
+            "scientific",
+            "scientific_small",
+            "scientific_uppercase_and_whitespace",
+            "scientific_from_ambient",
+            "scientific_negative",
+            "fractional",
+            "fractional_below_one",
+            "infinite",
+            "nan",
+            "huge_integer_stays_exact",
         ],
     )
     def test_parse(self, monkeypatch, options_env, ambient, expected):