feat(event): accept any sequence of events where a list of them is accepted

[benedikt-bartscher]

An event prop accepted a list literal of events, but not a list variable:

events: list[EventSpec] = [rx.redirect("/x"), rx.console_log("y")]
rx.button(on_click=events)  # rejected by pyright and ty

EventType spelled its list form list[...] of every kind of event, and lists are
invariant, so a list[EventSpec] or a list[EventCallback[()]] is not one of those.
At runtime the same holds for tuples: EventChain.create, format_queue_events,
Event.from_event_type and fix_events only took a list, while call_event_fn
already took a tuple from a lambda and _check_valid_yield already let a handler
return a tuple (return a, b), which from_event_type then rejected as an
unexpected event type.

EventType now spells it Sequence[...], which is covariant, and those places
take any sequence other than a string through is_non_string_sequence, a TypeIs
helper in reflex_base.utils.types, so the runtime accepts exactly what the type
does. A Var is not a Sequence, so nothing that was a single event becomes a
sequence. A page's on_load (App._commit_page) reads the value the same way, so
on_load=(a, b) registers both events instead of one tuple. The internal demo and
intro forms check their on_submit against Sequence directly, since their
declared reflex floor predates the helper, and reject a string up front.

from_event_type runs for every event a handler returns, so it checks the single
event kinds before the Sequence ABC, as _check_valid_yield does: a single
Event, EventSpec or callable costs what it did with the list check.

tests/type_checking/event.py passes a list[EventSpec] variable and a tuple of
handlers to an EventType[()] parameter; it fails under pyright and ty before this
change. Unit tests cover a tuple in each of the runtime places, the full unit suite
and pyright pass.

[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge; the dependency-floor change addresses the outstanding import failure.

Summary

The PR lets event props, returned events, page loaders, and internal forms accept non-string sequences.

• Event props and handler results accept any non-string sequence of events.
• Pages register every event in an on_load tuple.
• The demo and intro forms accept tuple submit events.

_{Reviews (15) · Last reviewed commit: "build(internal): require the reflex that..." · Reviewed by Greptile}

[codspeed]

Merging this PR will degrade performance by 4.05%

⚠️ 12 benchmarks spent significant time in system calls

System calls cannot be consistently instrumented, so they are not included in the measure, which understates the real cost. Please switch to the Walltime instrument to accurately measure system calls.

Measurement and system calls

• test_get_state[disk]
• test_state_manager_memory_modify
• test_cli_startup[run_help]
• test_cli_startup[cloud_help]
• test_cli_startup[version]
• test_cli_startup[help]
• test_cli_startup[deploy_help]
• test_get_state[memory]
• test_set_state[disk]
• test_import_cli
• …and 2 more

❌ 1 regressed benchmark
✅ 147 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	test_hydration_snapshot[200]	8.6 ms	8.9 ms	-4.05%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing benedikt-bartscher:event-sequences (dc13e2e) with main (81f463b)}

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[cubic-dev-ai]

All reported issues were addressed across 10 files (changes from recent commits).

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[cubic-dev-ai]

All reported issues were addressed across 5 files (changes from recent commits).

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