fix(recommendations/aws): plumb on_demand_cost for canonical Effective Savings % (closes #303) by cristim · Pull Request #312 · LeanerCloud/CUDly

cristim · 2026-05-05T20:07:21Z

Summary

Plumbs OnDemandCost for AWS Savings Plans recommendations by computing it from CurrentAverageHourlyOnDemandSpend × 730 in parseSavingsPlanDetail — the same field AWS Cost Explorer uses internally for EstimatedSavingsPercentage.
AWS RI was already plumbed (via parseAWSCostDetails → EstimatedMonthlyOnDemandCost) and the scheduler already forwarded it (both landed in fix(recommendations): plumb provider on_demand_cost through to frontend (closes #274) #277); this PR closes the SP gap.
Adds TestParseSavingsPlanDetail_OnDemandCost in parser_sp_additional_test.go (SP provider regression test, AC Fix AWS RI purchase: details assertion + reservation ID rules #4).
Adds AWS RI + SP frontend fixtures inside the existing on_demand_cost preference (#274) describe block (AC AWS + Azure: add read-only sanity checks + AWS RI exchange #3).

Acceptance criteria check

AWS recommendations carry a non-null on_demand_cost from the provider all the way to RecommendationRecord and the API payload — RI: existing parseAWSCostDetails; SP: this PR.
effectiveSavingsPct() resolves to the same value as the underlying provider report for AWS RIs and Savings Plans — formula unchanged from bug(frontend/recs): Effective % shows implausible values (85.9% on Azure 1y RI, 54% on savings=$0 row) #274; this PR ensures the provider-supplied denominator reaches the frontend for SP.
Unit test in frontend/src/__tests__/recommendations.test.ts pinning the expected effective % for at least one AWS RI fixture and one SP fixture — added in this PR.
Regression test in the AWS provider mapping asserting OnDemandCost is populated — TestParseRecommendationDetail_WithAccountAndCosts (RI, pre-existing) + TestParseSavingsPlanDetail_OnDemandCost (SP, this PR).

Reference

Pattern mirrors PR #277 (commit 66a993fa5) which fixed the same bug for Azure 1y RIs.

Closes #303

Summary by CodeRabbit

Bug Fixes
- Improved accuracy of AWS Savings Plans recommendation calculations by properly computing on-demand cost baselines, ensuring effective savings percentages align with AWS Cost Explorer data for EC2 RI, Compute Savings Plans, and other plan types.
Tests
- Enhanced test coverage validating on-demand cost calculations across multiple AWS recommendation scenarios.

closes #303) The AWS Savings Plans parser did not populate common.Recommendation.OnDemandCost, so effectiveSavingsPct() fell back to reconstructing the on-demand denominator from monthly_cost + savings + amortized. For SP rows monthly_cost reflects only the recurring commitment charge, not the full on-demand baseline, so the reconstruction is inaccurate. Fix: derive OnDemandCost from CurrentAverageHourlyOnDemandSpend × 730 in parseSavingsPlanDetail — the same field AWS Cost Explorer uses internally when computing EstimatedSavingsPercentage. The scheduler's existing nonZeroPtr helper (added in #277) converts 0 → nil so the frontend falls back to reconstruction when the field is absent, preserving backward compatibility. The AWS RI parser already populated OnDemandCost (from EstimatedMonthlyOnDemandCost via parseAWSCostDetails) and the scheduler already plumbs it through to RecommendationRecord — both landed in #277. This commit closes the SP gap and adds the AWS-specific frontend and provider regression tests the AC list requires.

coderabbitai · 2026-05-05T20:07:28Z

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Reviewing files that changed from the base of the PR and between f83c914 and 4df8dab.

📒 Files selected for processing (3)

frontend/src/__tests__/recommendations.test.ts
providers/aws/recommendations/parser_sp.go
providers/aws/recommendations/parser_sp_additional_test.go

📝 Walkthrough

Walkthrough

This PR plumbs the AWS provider-supplied on_demand_cost from the Savings Plans parser through to the frontend to enable correct Effective Savings % calculations. Backend parsing now computes OnDemandCost from hourly on-demand spend; frontend and backend tests validate the computation and usage.

Changes

AWS On-Demand Cost Plumbing

Layer / File(s)	Summary
Data Shape & Backend Parsing `providers/aws/recommendations/parser_sp.go`	`parseSavingsPlanDetail` computes `OnDemandCost` from `CurrentAverageHourlyOnDemandSpend * hoursPerMonth` and populates the returned `common.Recommendation` struct with this value, with explanatory comments on its semantics.
Backend Tests `providers/aws/recommendations/parser_sp_additional_test.go`	`TestParseSavingsPlanDetail_OnDemandCost` validates that `rec.OnDemandCost` is correctly computed from hourly on-demand spend when present, and defaults to `0` when absent.
Frontend Tests `frontend/src/__tests__/recommendations.test.ts`	Added AWS provider fixtures test suite covering EC2 RI, Compute Savings Plans, and Savings Plans scenarios; verifies `effectiveSavingsPct` uses provider-supplied `on_demand_cost` as the denominator and matches expected percentage values.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

LeanerCloud/CUDly#277: Fixed the same issue for Azure RIs by plumbing on_demand_cost to the frontend; this PR applies the same pattern to AWS Savings Plans.
LeanerCloud/CUDly#254: Earlier changes to AWS Savings Plans parsing logic and frontend effectiveSavingsPct behavior that are related to the data flow modified here.

Poem

🐰 A parser that once forgot the cost,
Now multiplies hourly, like dew drops lost;
On-demand at last! The savings shine bright,
Percentages true from backend to sight! ✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main change: plumbing on_demand_cost for AWS Savings Plans to fix Effective Savings % calculations, matching the primary objective stated in issue `#303`.
Linked Issues check	✅ Passed	All acceptance criteria from `#303` are met: on_demand_cost is plumbed for AWS SP via parser_sp.go, frontend fixtures added for AWS RI and SP, regression test TestParseSavingsPlanDetail_OnDemandCost validates OnDemandCost population, and effectiveSavingsPct() usage is enabled by the plumbing.
Out of Scope Changes check	✅ Passed	All changes are within scope: backend plumbing of OnDemandCost for AWS Savings Plans, frontend test fixtures for AWS RI and SP, and regression tests directly support closing `#303` without extraneous modifications.

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Commit unit tests in branch fix/issue-303-aws-savings-pct

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cristim · 2026-05-05T20:07:49Z

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coderabbitai · 2026-05-05T20:07:54Z

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…isibility (closes #321) (#324) * fix(db/aws): flush stale recs cache missing on_demand_cost (migration 000049) PR #312 added on_demand_cost population for AWS SP rows but shipped no cache-invalidation migration. Pre-#312 AWS rows in recommendations.payload lack the on_demand_cost key, so the frontend falls back to the broken reconstruction formula (which double-counts amortization), rendering implausibly high Effective % values (e.g. ~86% instead of ~22%). Migration 000049 follows #256's pattern: set monthly_cost to null on AWS rows that lack on_demand_cost, so the frontend renders "—" until the next scheduler tick repopulates with correct values. The WHERE clause is scoped strictly to AWS rows missing the field (idempotent on re-run). Closes #321 * fix(recommendations/aws): warn-log when on-demand cost inputs are nil Add structured warn-logs in the RI and SP parsers when the AWS CE API fields that populate OnDemandCost are absent from the response: - parseAWSCostDetails (parser_ri.go): logs when EstimatedMonthlyOnDemandCost is nil, which causes OnDemandCost=0 → stored as nil by the scheduler's nonZeroPtr helper → frontend reconstruction fallback. - parseSavingsPlanDetail (parser_sp.go): logs when CurrentAverageHourlyOnDemandSpend is nil, same downstream effect. Both logs follow the respective file's existing logging style (fmt.Printf for parser_ri.go, log.Printf for parser_sp.go). The logs make it observable when the fallback path is taken, aiding diagnosis for issue #321 and future regression detection. * fix: apply CodeRabbit auto-fixes Fixed 1 file(s) based on 1 unresolved review comment. Co-authored-by: CodeRabbit <noreply@coderabbit.ai> --------- Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com> Co-authored-by: CodeRabbit <noreply@coderabbit.ai>

cristim added priority/p1 Next up; this sprint severity/high Significant harm urgency/this-sprint Within the current sprint impact/all-users Affects every user effort/m Days type/bug Defect triaged Item has been triaged labels May 5, 2026

cristim merged commit c94c44a into feat/multicloud-web-frontend May 5, 2026
5 of 6 checks passed

This was referenced May 6, 2026

fix(recommendations/aws): Effective % still shows wrong values — stale JSONB cache lacks on_demand_cost (followup to #312) #321

Open

fix(recommendations/aws): flush stale on_demand_cost cache + parser visibility (closes #321) #324

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This was referenced May 7, 2026

feat(frontend/recs): On-Demand Monthly column should use provider on_demand_cost directly (no reconstruction) #330

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feat(frontend/recs): On-Demand Monthly uses provider on_demand_cost directly (closes #330) #331

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fix(recommendations/aws): plumb on_demand_cost for canonical Effective Savings % (closes #303)#312

fix(recommendations/aws): plumb on_demand_cost for canonical Effective Savings % (closes #303)#312
cristim merged 1 commit intofeat/multicloud-web-frontendfrom
fix/issue-303-aws-savings-pct

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