fix(cron): accept bare cron-expression string in Schedule deserializer

[graycyrus]

Summary

• Root cause (Sentry CORE-RUST-FY / Cron update fails: Schedule field rejects bare cron strings #2866): openhuman.cron_update deserializes the schedule field as an internally-tagged Schedule enum. Agents and some frontend callers send a bare string like "0 9 * * 1" instead of the structured form {"kind":"cron","expr":"0 9 * * 1"}. Serde rejected this with: invalid type: string, expected internally tagged enum Schedule.
• Fix: Custom Deserialize impl for Schedule in src/openhuman/cron/types.rs. A bare string is coerced to Schedule::Cron { expr, tz: None, active_hours: None }; the full object form still works as before. Serialization is unchanged.
• Tests: 4 new unit tests cover: bare string deserialization, 5-field cron string, CronJobPatch with bare string (exact failing shape), and regression guard for the structured object form. All 20 cron::types tests pass.

Test plan

• cargo test --lib openhuman::cron::types — all 20 pass
• cargo check — clean (no new errors)
• Manual: send {"method":"openhuman.cron_update","params":{"job_id":"<id>","patch":{"schedule":"0 9 * * 1"}}} — should succeed instead of returning deserialization error

Summary by CodeRabbit

• New Features

  • Cron schedules now accept a simplified string format (e.g., "0 9 * * 1") in addition to the structured object form; both formats are supported for schedule fields.
  • Backward compatibility preserved for existing configurations.

• Tests

  • Added tests covering string-based cron parsing, including 5-field and 6-field cron expressions and acceptance in job patch payloads.

[coderabbitai]

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: c1460988-3cb2-4d45-9c4c-67971ba56162

📥 Commits

Reviewing files that changed from the base of the PR and between 1cb015e and 9f27d7d.

📒 Files selected for processing (1)

• src/openhuman/cron/types.rs

📝 Walkthrough

Walkthrough

Schedule deserialization now uses a custom Serde Visitor: JSON strings are coerced into Schedule::Cron (tz and active_hours set to None), and map/object inputs are deserialized via the existing internally-tagged representation. Tests cover both input forms.

Changes

Cron Schedule deserialization

Layer / File(s)	Summary
Imports and struct setup src/openhuman/cron/types.rs	Serde imports expanded to include Deserializer; Schedule derive list removes Deserialize and docs added describing dual-format parsing (bare cron string or internally-tagged object).
Custom Deserialize visitor implementation src/openhuman/cron/types.rs	Manual Deserialize impl using a Visitor that coerces bare &str/String into Schedule::Cron { expr, tz: None, active_hours: None } and delegates map inputs to a locally-defined internally-tagged enum mapped back to Schedule.
Deserialization tests src/openhuman/cron/types.rs	Unit tests cover bare cron string deserialization into Schedule::Cron (5-field and 6-field) and verify CronJobPatch.schedule accepts both bare string and structured tagged object payloads.

Sequence Diagram

sequenceDiagram
  participant Input as JSON Input
  participant Visitor as ScheduleVisitor
  participant Cron as Schedule::Cron
  participant Tagged as TaggedEnum
  Input->>Visitor: "0 9 * * 1" (bare string)
  Visitor->>Cron: coerce to Cron { expr, tz=None, active_hours=None }
  Input->>Visitor: {"kind":"cron","expr":"0 9 * * 1"} (tagged object)
  Visitor->>Tagged: deserialize tagged enum
  Tagged->>Visitor: map to Schedule::Cron variant

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related issues

• Cron update fails: Schedule field rejects bare cron strings #2866: Implements the custom Deserialize behavior described in that issue to accept bare cron strings and tagged objects.

Poem

🐰 Hopping through formats with a twitchy whisker,
Bare strings or objects, the parser grows brisker.
A Visitor nibbles each incoming token,
Turning crons to variants—no errors to beckon.
Celebrate the hop, schedule’s now slicker!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The PR title clearly and concisely summarizes the main change: accepting bare cron-expression strings in the Schedule deserializer, which directly addresses the fix for the deserialization error described in the PR objectives.
Docstring Coverage	✅ Passed	Docstring coverage is 90.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[coderabbitai]

Actionable comments posted: 0

[coderabbitai]

Actionable comments posted: 0

[M3gA-Mind]

Clean fix. The Deserialize visitor approach is idiomatic — deserialize_any dispatches to visit_str/visit_string for bare strings and visit_map (delegating via MapAccessDeserializer to an inner tagged-enum derivation) for the full object form. Serialization is unchanged so no wire-format regression.

Tests hit all four cases: bare 5-field string, 6-field ( */5), CronJobPatch with bare string (exact CORE-RUST-FY payload), and regression guard for the structured object form.

One minor observation: visit_string duplicates the body of visit_str rather than forwarding (self.visit_str(value.as_str())), but both are functionally correct and the duplication is minimal.

Approving — waiting on CI green to merge.

[M3gA-Mind]

The branch has fix(observability): classify Embedding API 401 Invalid-token as SessionExpired on top as an extra commit, which was already merged to main independently as #2869. This puts the PR in mergeable_state: dirty and blocks CI.

I've opened #2874 with the two cron-fix commits cleanly rebased on current main (the observability commit dropped since it's already in main). Functionally identical to this PR. Recommending we close this in favour of #2874.