test: cover lifecycle init/post_upgrade argument validation

[mbjorkqvist]

Closes a test gap surfaced during the repo review: lifecycle.rs had no mod tests, leaving the operator-facing init/upgrade arg-validation and snapshot-recovery branches — the code paths exercised at the worst possible time, during an upgrade — entirely untested.

Adds a tests module covering:

• init traps when handed an Upgrade argument.
• post_upgrade traps when the state snapshot is missing (i.e. pre_upgrade trapped or was skipped).
• post_upgrade traps when handed an Init argument.

Test-only; no production code changed.

[Copilot]

Pull request overview

Adds a #[cfg(test)] unit test module to canister/src/lifecycle.rs to cover upgrade lifecycle argument validation and snapshot-missing failure behavior, addressing previously untested operator-critical paths during upgrades.

Changes:

• Add a test ensuring init panics when passed an Upgrade argument.
• Add a test ensuring post_upgrade panics when no state snapshot is available.
• Add a test ensuring post_upgrade panics when passed an Init argument (with a snapshot present so validation is reached).

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[github-actions]

canbench 🏋 (dir: canister) 6894f40 2026-06-23 06:15:43 UTC

✅ canister/canbench_results.yml is up to date
📦 canbench_results_benchmark.csv available in artifacts

---------------------------------------------------

Summary:
  instructions:
    status:   No significant changes 👍
    counts:   [total 12 | regressed 0 | improved 0 | new 0 | unchanged 12]
    change:   [max +794.90K | p75 +63.93K | median +154 | p25 -220.35K | min -1.82M]
    change %: [max +0.47% | p75 +0.15% | median +0.03% | p25 -0.11% | min -1.02%]

  heap_increase:
    status:   No significant changes 👍
    counts:   [total 12 | regressed 0 | improved 0 | new 0 | unchanged 12]
    change:   [max 0 | p75 0 | median 0 | p25 0 | min 0]
    change %: [max 0.00% | p75 0.00% | median 0.00% | p25 0.00% | min 0.00%]

  stable_memory_increase:
    status:   No significant changes 👍
    counts:   [total 12 | regressed 0 | improved 0 | new 0 | unchanged 12]
    change:   [max 0 | p75 0 | median 0 | p25 0 | min 0]
    change %: [max 0.00% | p75 0.00% | median 0.00% | p25 0.00% | min 0.00%]

---------------------------------------------------

Only significant changes:
| status | name                               | calls |    ins |  ins Δ% | HI |  HI Δ% | SMI |  SMI Δ% |
|--------|------------------------------------|-------|--------|---------|----|--------|-----|---------|
|   -    | bench_write_events::AddTradingPair |     1 | 16.95K |  -2.04% |  0 |  0.00% |   0 |   0.00% |
|   -    | bench_write_events::Deposit        |     1 | 10.30K |  -2.15% |  0 |  0.00% |   0 |   0.00% |
|   -    | bench_write_events::Init           |     1 | 23.13K |  -2.71% |  0 |  0.00% |   0 |   0.00% |

ins = instructions, HI = heap_increase, SMI = stable_memory_increase, Δ% = percent change

---------------------------------------------------
CSV results saved to canbench_results.csv

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[zeropath-ai]

✅ No security or compliance issues detected. Reviewed everything up to c756abd.

Security Overview

• 🔎 Scanned files: 2 changed file(s)
• 🔗 Scan Link: https://zeropath.com/app/repositories/a2241de7-cf71-4864-8711-25a8fbfe66c5?scanId=b478e48e-6459-4304-bc7f-fb78988877be&codeScanTypes=PrScan&tab=issues

Detected Code Changes

Change Type	Relevant files
Refactor	► canister/src/lifecycle.rs     Rename lifecycle.rs to mod.rs     Add #[cfg(test)] for tests module
Enhancement	► canister/src/lifecycle/tests.rs     Add tests for init function     Add tests for post_upgrade function

[gregorydemay]

Thanks @mbjorkqvist !