Keep the two tests that fail on main without the fix:
- test_fal_common: a keyed managed submit makes exactly one POST (plus the
negative arm: an unkeyed submit still goes through the SDK retry ladder)
- test_image_generation: the 409 BILLING_ERROR body surfaces
`unsupported_pricing_meter` instead of the generic "not yet enabled" text
Dropped from #106484: the duplicate video-plugin billing test (same helper,
same assertion), the `_fal_client = fake` / `import_fal_client` stub churn
and the `tools.lazy_deps` stub — fal-client is installed in CI (`--extra fal`)
so those fixtures were not needed; the `_load_fal_client` no-op fixture on
TestManagedGatewayErrorTranslation for the same reason.
Also drop the redundant `retry_request is None` re-check in
`_ManagedFalSyncClient.submit` — `__init__` already raises when the helper
is missing.
Avoid retrying idempotent managed FAL submissions because the retry can mask the initial billing failure. Surface structured Nous billing diagnostics consistently for image and video paths, with hermetic regression coverage.
(cherry picked from commit 289ce039e9a522dc8016ae4a512214c05d0a8bc0)
Contract tests for tools/fal_common.py: queue-URL normalization
(trailing slash / whitespace / empty-raises), _extract_http_status
response-vs-exc precedence and non-int rejection, the
_ManagedFalSyncClient RuntimeError guards against fal_client private
API drift, and submit()'s queue-URL + POST/json/timeout wiring.
Trimmed on landing: test_non_string_coerced_to_string (pins an
implementation accident, not a contract) per the coverage-padding
policy in AGENTS.md.
Salvaged from #52166.
teknium1