[CT-17] Write Subscription Lifecycle Test Suite (12+ tests) in Rust

[devwums]

Problem

The manage_hub subscription contract has no comprehensive test coverage for the full subscription lifecycle. Bugs in create, renew, expiry, and grace period logic go undetected until production.

Proposed Solution

Create contracts/cntr/tests/subscription_lifecycle_tests.rs. Write at least 12 unit tests covering: valid subscription creation, renewal before expiry, renewal during grace period, renewal after full expiry (must fail), expiry detection at exact boundary, grace period start boundary, grace period end boundary, and tier upgrade path after renewal. Import and use the modules from contracts/cntr/. All implementation must live inside contracts/cntr/.

Acceptance Criteria

• File at contracts/cntr/tests/subscription_lifecycle_tests.rs
• At least 12 test functions with descriptive snake_case names (e.g., test_renewal_during_grace_period)
• Each test function has a single-line doc comment describing the scenario
• Tests use subscription_expiry.rs and grace_period.rs peer modules
• All tests pass with cargo test

[auracule007]

@auracule007 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi maintainers, I'm Promise. I'm a full-stack developer with 4+ years of experience in Rust and smart contract testing. I'd like to work on this subscription lifecycle test suite. I can write 12+ tests covering creation, renewal, expiry boundaries, grace periods, and tier upgrades. My ETA is 5-8 hours.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @auracule007 to this issue.

[Hassan-oladipupo]

@Hassan-oladipupo has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi maintainer can i take this

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Hassan-oladipupo to this issue.

[drips-wave]

Congratulations, @Hassan-oladipupo! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @Hassan-oladipupo: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

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