fix(cmd): refuse an EC2 Instance Savings Plan without a family in the dry run too

[cristim]

Closes #2164

Summary

For an EC2 Instance Savings Plan, validatePurchasePreconditions (added in #2160) only checked Details.Region. When InstanceFamily and OfferingID were both empty, the dry run reported success, but the real run refused it.

Why the real run refuses: with no family, buildSPOfferingsInput (savingsplans/client.go:372) drops the family filter. lookupEC2OfferingIDStrict (client.go:529-540) then sees several families and refuses the plan as ambiguous.

What this PR changes:

• A new validateEC2InstanceSPOffering refuses an EC2 Instance SP that has no family unless an OfferingID is set. A set OfferingID skips the lookup in findOfferingID (client.go:467), so it passes. Region is still required.
• The dry run now refuses exactly where the real run would.
• Compute, SageMaker and Database SPs are unaffected.
• The fix(cmd): reject Savings Plan hourly commitments that round to 0.00 #2209 hourly-commitment checks still run first, in the same order.
• The recommendation-completeness fixture now carries InstanceFamily: "m5", as a real recommendation does. The AWS parser sets it at parser_sp.go:273, and the CSV reader reads it at multi_service_csv_details.go:90.
• CHANGELOG.md has a Fixed entry.

Known gap (low): a whitespace-only family still passes the dry run, and the real run then finds no offerings. Neither the CSV reader nor Cost Explorer produces that value in practice.

Evidence (local, macOS, GOTOOLCHAIN=go1.26.9, unit tests)

• Fail before / pass after: with the source change stashed, TestValidatePurchasePreconditions/ec2 instance sp no family no offering fails ("An error is expected but got nil"). It passes with the change. The new cases also cover an offering ID with no family (passes) and a Compute SP with no family (passes).
• Mutation probes (reviewer): dropping the OfferingID condition, or making the check never fire, each fails a case.
• Checks:
  • make build, go vet ./... and the targeted race tests pass (124 tests).
  • golangci-lint v2.10.1 reports 0 issues.
  • scripts/test-git-secrets-allowlist.sh passes 44/44.
  • TestArcheraHostileLargeDecodeValueIsBounded failed once under machine load, both with and without this change. It passes alone on main and on HEAD. It is tracked in test(archera): TestArcheraHostileLargeDecodeValueIsBounded fails under machine load (1s wall-clock bound) #2259.
• Review: two passes by an independent non-author reviewer (sonnet, high) found no actionable findings at d0d9a9b7.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Dry runs now reject EC2 Instance Savings Plans that lack both an instance family and an offering ID, matching the checks performed during a purchase.
  • EC2 Instance Savings Plans must include a region and either an instance family or an offering ID. An offering ID can be provided without an instance family, while blank or whitespace-only family values do not satisfy the requirement.

[coderabbitai]

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• Configuration used: Repository: LeanerCloud/cloud-commitments-cli/.coderabbit.yaml
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📥 Commits

Reviewing files that changed from the base of the PR and between b8ecf51 and 6f8b09d.

📒 Files selected for processing: 2

• cmd/savings_plan_purchase.go
• cmd/savings_plan_purchase_test.go

🚧 Files skipped from review as they are similar to previous changes: 2

• cmd/savings_plan_purchase.go
• cmd/savings_plan_purchase_test.go

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📝 Walkthrough

EC2 Instance Savings Plan precondition validation now requires a region and either a nonblank instance family or an offering ID. Tests, a recommendation fixture, and the changelog reflect this validation.

Changes: EC2 Instance Savings Plan validation

Layer / File(s)	Summary
Precondition validation and coverage cmd/savings_plan_purchase.go, cmd/savings_plan_purchase_test.go, cmd/recommendation_completeness_proxy_test.go, CHANGELOG.md	Validation requires a region and, when no offering ID is set, a nonblank instance family. Tests cover valid and invalid preconditions. The recommendation fixture now includes an instance family, and the changelog records the dry-run behavior.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix · Severity of issue fixed: Medium

Merge Risk: ⚪ Minimal · up to 6f8b0

Dry runs now refuse the targeted EC2 plans with no family or offering ID, matching the intended purchase precondition. No actionable merge-blocking risk remains after normal checks.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 3 functions across 3 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main change: rejecting EC2 Instance Savings Plans without a family during dry runs.
Linked Issues check		Issue #2164 requires rejection when an EC2 Instance Savings Plan has no usable InstanceFamily and no OfferingID. validateEC2InstanceSPOffering requires Region and rejects an empty or whitespac…
Out of Scope Changes check		The reviewed changes are limited to the EC2 Instance Savings Plan precondition, focused tests, the recommendation-completeness fixture, and the related changelog entry. These changes support issue #21…

Full details: Linked Issues check

Explanation

Issue #2164 requires rejection when an EC2 Instance Savings Plan has no usable InstanceFamily and no OfferingID. validateEC2InstanceSPOffering requires Region and rejects an empty or whitespace-only family when OfferingID is empty. An OfferingID bypasses the family check. The check runs only for EC2 Instance Savings Plans. Tests cover the rejection, whitespace-only input, offering-ID bypass, and unaffected Compute plans. The completeness fixture supplies InstanceFamily: "m5".

Full details: Out of Scope Changes check

Explanation

The reviewed changes are limited to the EC2 Instance Savings Plan precondition, focused tests, the recommendation-completeness fixture, and the related changelog entry. These changes support issue #2164. No unrelated change is established by the supplied evidence.

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[cristim]

Independent review verdict: CLEAN at b185c2c

Reviewer: fresh Claude agent (Sonnet 5.5, high effort), not the author, cold brief. Coordinator: claude-cc-reviewer.

What was checked

• Dry run and purchase share one gate. validatePurchasePreconditions runs before the isDryRun branch on both the main path (cmd/multi_service.go:620) and the CSV path (:1010). The dry-run preview now refuses the same plan that the real run would refuse.
• The refusal is recorded as a failure; it does not abort the run. It goes through preconditionFailure (cmd/savings_plan_purchase.go:175), the same way as the existing region check.
• The check is narrowly scoped. It is at cmd/savings_plan_purchase.go:163-171 and applies only when rec.Service == ServiceSavingsPlansEC2Instance. An explicit OfferingID skips it, which matches the library (savingsplans client.go:467). Compute and the other Savings Plan types are unaffected.
• Mutation probes:
  • With the check disabled, TestValidatePurchasePreconditions fails.
  • With the check applied to Compute SP, these fail: the TestExecuteAndReport_*SavingsPlan* tests, TestRunCSVPurchases_SavingsPlanFailureFailsRun, and 8+ completeness subtests.
  • The new tests fail against the implementation on origin/main.
• Builds and checks. go test -race ./cmd/... -count=1 passes, go vet is clean, and golangci-lint reports 0 issues. All of this is fixture-based.

Non-blocking notes

• A family made only of whitespace still passes the check. The library then finds no offerings and fails. No test covers this case.
• The check keys on rec.Service, not on PlanType, so a Service/PlanType mismatch is not covered.

Gate

• Labels are mirrored from fix(cmd): dry run accepts an EC2 Instance Savings Plan the real run refuses when InstanceFamily is unset #2164.
• CodeRabbit is rate limited. It is optional here, because exact-revision verification plus this review cover the SHA.
• Merge once CI is green.

[coderabbitai]

Actionable comments posted: 1

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🤖 Prompt to fix review comments

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Inline comments:
Review comments at @cmd/savings_plan_purchase.go:
- Around line 154-169: Update validateEC2InstanceSPOffering to treat
whitespace-only InstanceFamily values as missing when OfferingID is empty, using
whitespace trimming in the existing validation guard.

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ℹ️ Review info

⚙️ Run configuration

• Configuration used: Repository: LeanerCloud/cloud-commitments-cli/.coderabbit.yaml
• Review profile: CHILL
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• Run ID: 761e4c1d-063b-401a-bad8-dd208503a4d3

📥 Commits

Reviewing files that changed from the base of the PR and between 0c869b4 and b8ecf51.

📒 Files selected for processing: 4

• CHANGELOG.md
• cmd/recommendation_completeness_proxy_test.go
• cmd/savings_plan_purchase.go
• cmd/savings_plan_purchase_test.go

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