fix(recommendations): use pool demand for expiry coverage

cmd/multi_service_helpers.go

@@ -537,10 +537,13 @@ func applyRegionFilters(
 func applyCoverageAndOverrides(recs []common.Recommendation, cfg Config, coverageMap recommendations.PoolCoverageMap, expiringCommitments []common.Commitment, drops *common.DropSummary) []common.Recommendation {
 	recommendations.ApplyCoverageMapToRecommendations(recs, coverageMap)
 	if cfg.RebuyWindowDays > 0 && len(expiringCommitments) > 0 {
-		n := recommendations.AdjustExistingCoverageForExpiringCommitments(recs, expiringCommitments, cfg.RebuyWindowDays)
+		n, missingDemand := recommendations.AdjustExistingCoverageForExpiringCommitmentsWithCoverage(recs, expiringCommitments, cfg.RebuyWindowDays, coverageMap)
 		if n > 0 {
 			AppLogger.Printf("  ⏰ Treating %d recs as partially uncovered (RIs expiring within %d days)\n", n, cfg.RebuyWindowDays)
 		}
+		if missingDemand > 0 {
+			AppLogger.Printf("  ⚠️  Skipped expiry adjustment for %d recommendations because pool demand was unavailable; coverage was left unchanged\n", missingDemand)
+		}
 	}
 	// Family-NU sizing for RDS recs: AWS rec API already bundles size-flex
 	// demand within a family into one rec at one size, so per-pool sizing

cmd/reservation_expiry_test.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"math"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/LeanerCloud/cloud-commitments-go/pkg/common"
+	"github.com/LeanerCloud/cloud-commitments-go/providers/aws/recommendations"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestReservationExpirySizing(t *testing.T) {
+	for _, tc := range []struct {
+		name                     string
+		averages                 []float64
+		wantCounts               []int
+		wantAverages             []float64
+		demand, target, existing float64
+		expiry, endDays          int
+		exclude                  []string
+	}{
+		{"equal-shares", []float64{30, 30, 30}, []int{12, 12, 12}, []float64{30, 30, 30}, 90, 80, 40, 18, 15, nil},
+		{"unequal-shares", []float64{15, 30, 45}, []int{6, 12, 18}, []float64{15, 30, 45}, 90, 80, 40, 18, 15, nil},
+		{"zero-raw-shares", []float64{0, 0, 0}, []int{12, 12, 12}, []float64{30, 30, 30}, 90, 80, 40, 18, 15, nil},
+		{"filtered-two", []float64{30, 30, 30}, []int{18, 18}, []float64{45, 45}, 90, 80, 40, 18, 15, []string{"expiry-account-3"}},
+		{"filtered-one", []float64{30, 30, 30}, []int{36}, []float64{90}, 90, 80, 40, 18, 15, []string{"expiry-account-2", "expiry-account-3"}},
+		{"outside-window", []float64{30, 30, 30}, []int{6, 6, 6}, []float64{30, 30, 30}, 90, 80, 60, 18, 180, nil},
+		{"exact-boundary", []float64{15, 15}, []int{4, 4}, []float64{15, 15}, 30, 80, 160.0 / 3, 2, 15, nil},
+		{"below-boundary", []float64{15, 15}, []int{3, 3}, []float64{15, 15}, 30, math.Nextafter(80, 0), 160.0 / 3, 2, 15, nil},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			recs := reservationExpiryRecommendations(tc.averages)
+			cfg := Config{TargetCoverage: tc.target, RebuyWindowDays: 30, IncludeExtendedSupport: true, ExcludeAccounts: tc.exclude}
+			filtered := applyRegionFilters(recs, engineVersionData{}, "us-east-1", cfg, nil)
+			got := applyCoverageAndOverrides(filtered, cfg, recommendations.PoolCoverageMap{
+				"us-east-1:m5.large": {Pct: 60, AvgInstancesPerHour: tc.demand},
+			}, reservationExpiryCommitments(tc.expiry, tc.endDays), nil)
+			require.Len(t, got, len(tc.wantCounts))
+			for i := range got {
+				assertReservationExpirySizedRow(t, got[i], tc.wantCounts[i], tc.wantAverages[i], tc.existing)
+				require.NotNil(t, recs[i].RecurringMonthlyCost)
+				assert.Equal(t, 300.0, *recs[i].RecurringMonthlyCost, "input monthly pointer must remain unmodified")
+			}
+		})
+	}
+}
+
+func TestReservationExpiryMissingDemand(t *testing.T) {
+	for _, tc := range []struct {
+		name     string
+		coverage recommendations.PoolCoverageMap
+	}{
+		{"nil-map", nil},
+		{"missing-key", recommendations.PoolCoverageMap{"us-west-2:m5.large": {Pct: 60, AvgInstancesPerHour: 90}}},
+		{"zero", recommendations.PoolCoverageMap{"us-east-1:m5.large": {Pct: 60}}},
+		{"negative", recommendations.PoolCoverageMap{"us-east-1:m5.large": {Pct: 60, AvgInstancesPerHour: -1}}},
+		{"nan", recommendations.PoolCoverageMap{"us-east-1:m5.large": {Pct: 60, AvgInstancesPerHour: math.NaN()}}},
+		{"infinite", recommendations.PoolCoverageMap{"us-east-1:m5.large": {Pct: 60, AvgInstancesPerHour: math.Inf(1)}}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			var output bytes.Buffer
+			previous := AppLogger.Writer()
+			AppLogger.SetOutput(&output)
+			t.Cleanup(func() { AppLogger.SetOutput(previous) })
+			cfg := Config{TargetCoverage: 80, RebuyWindowDays: 30}
+			baseline := applyCoverageAndOverrides(reservationExpiryRecommendations([]float64{10, 10, 10}), cfg, tc.coverage, nil, nil)
+			output.Reset()
+			got := applyCoverageAndOverrides(reservationExpiryRecommendations([]float64{10, 10, 10}), cfg, tc.coverage, reservationExpiryCommitments(18, 15), nil)
+			require.Len(t, got, len(baseline))
+			for i := range got {
+				assert.Equal(t, baseline[i].Count, got[i].Count)
+				assert.Equal(t, baseline[i].ExistingCoveragePct, got[i].ExistingCoveragePct)
+				assert.Equal(t, baseline[i].CommitmentCost, got[i].CommitmentCost)
+				assert.Equal(t, baseline[i].OnDemandCost, got[i].OnDemandCost)
+				assert.Equal(t, baseline[i].EstimatedSavings, got[i].EstimatedSavings)
+				assert.Equal(t, baseline[i].RecurringMonthlyCost, got[i].RecurringMonthlyCost)
+			}
+			assert.Equal(t, 1, strings.Count(output.String(), "Skipped expiry adjustment for 3 recommendations because pool demand was unavailable; coverage was left unchanged"))
+		})
+	}
+}
+
+func TestReservationExpiryZeroDemandRow(t *testing.T) {
+	recs := reservationExpiryRecommendations([]float64{30, 0, 60})
+	got := applyCoverageAndOverrides(recs, Config{TargetCoverage: 80, RebuyWindowDays: 30}, recommendations.PoolCoverageMap{
+		"us-east-1:m5.large": {Pct: 60, AvgInstancesPerHour: 90},
+	}, reservationExpiryCommitments(18, 15), nil)
+	require.Len(t, got, 3)
+	assertReservationExpirySizedRow(t, got[0], 12, 30, 40)
+	assertReservationExpirySizedRow(t, got[2], 24, 60, 40)
+	assert.Equal(t, 30, got[1].Count)
+	assert.Equal(t, 60.0, got[1].ExistingCoveragePct)
+	assert.Equal(t, 3000.0, got[1].CommitmentCost)
+}
+
+func reservationExpiryRecommendations(averages []float64) []common.Recommendation {
+	recs := make([]common.Recommendation, len(averages))
+	for i, average := range averages {
+		monthly := 300.0
+		recs[i] = common.Recommendation{
+			Provider: common.ProviderAWS, Service: common.ServiceEC2, CommitmentType: common.CommitmentReservedInstance,
+			ResourceType: "m5.large", Region: "us-east-1", AccountName: fmt.Sprintf("expiry-account-%d", i+1),
+			Count: 30, RecommendedCount: 30, AverageInstancesUsedPerHour: average, ExistingCoveragePct: 60,
+			CommitmentCost: 3000, OnDemandCost: 6000, EstimatedSavings: 3000, RecurringMonthlyCost: &monthly,
+		}
+	}
+	return recs
+}
+
+func reservationExpiryCommitments(count, endDays int) []common.Commitment {
+	return []common.Commitment{{
+		Provider: common.ProviderAWS, Service: common.ServiceEC2, CommitmentType: common.CommitmentReservedInstance,
+		ResourceType: "m5.large", Region: "us-east-1", Count: count, State: common.CommitmentStateActive,
+		StartDate: time.Now().AddDate(-1, 0, 0), EndDate: time.Now().AddDate(0, 0, endDays),
+	}}
+}
+
+func assertReservationExpirySizedRow(t *testing.T, got common.Recommendation, count int, average, existing float64) {
+	t.Helper()
+	assert.Equal(t, count, got.Count)
+	assert.Equal(t, 30, got.RecommendedCount)
+	assert.InDelta(t, average, got.AverageInstancesUsedPerHour, 1e-12)
+	assert.InDelta(t, existing, got.ExistingCoveragePct, 1e-12)
+	assert.InDelta(t, existing+float64(count)*100/average, got.ProjectedCoverage, 1e-10)
+	assert.InDelta(t, 100, got.ProjectedUtilization, 1e-10)
+	assert.InDelta(t, float64(count)*100, got.CommitmentCost, 1e-10)
+	assert.InDelta(t, float64(count)*200, got.OnDemandCost, 1e-10)
+	assert.InDelta(t, float64(count)*100, got.EstimatedSavings, 1e-10)
+	require.NotNil(t, got.RecurringMonthlyCost)
+	assert.InDelta(t, float64(count)*10, *got.RecurringMonthlyCost, 1e-10)
+}

go.mod

@@ -82,8 +82,8 @@ require (
 
 require (
 	github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/authorization/armauthorization/v2 v2.2.0
-	github.com/LeanerCloud/cloud-commitments-go/pkg v0.0.0-20260929105827-b3b4cb5e3d80
-	github.com/LeanerCloud/cloud-commitments-go/providers/aws v0.0.0-20261003204812-9962786e0695
+	github.com/LeanerCloud/cloud-commitments-go/pkg v0.0.0-20261004235520-de46f760cdcf
+	github.com/LeanerCloud/cloud-commitments-go/providers/aws v0.0.0-20261005004231-945a4045d11f
 	github.com/LeanerCloud/cloud-commitments-go/providers/azure v0.0.0-20260928214714-ce9513612901
 	github.com/LeanerCloud/cloud-commitments-go/providers/gcp v0.0.0-20260928214714-ce9513612901
 	github.com/aws/aws-sdk-go-v2/service/organizations v1.45.3

go.sum

@@ -78,10 +78,10 @@ github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/cloudmock v0
 github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/cloudmock v0.54.0/go.mod h1:vB2GH9GAYYJTO3mEn8oYwzEdhlayZIdQz6zdzgUIRvA=
 github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/resourcemapping v0.54.0 h1:s0WlVbf9qpvkh1c/uDAPElam0WrL7fHRIidgZJ7UqZI=
 github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/resourcemapping v0.54.0/go.mod h1:Mf6O40IAyB9zR/1J8nGDDPirZQQPbYJni8Yisy7NTMc=
-github.com/LeanerCloud/cloud-commitments-go/pkg v0.0.0-20260929105827-b3b4cb5e3d80 h1:wVKlMokfaME/Lw525Qz3F155R3nY4VmuaIyh+6d4sCU=
-github.com/LeanerCloud/cloud-commitments-go/pkg v0.0.0-20260929105827-b3b4cb5e3d80/go.mod h1:ApWBliDXe099f3oDXBz41K/I9v4bHvn1dG/BGoRmHlw=
-github.com/LeanerCloud/cloud-commitments-go/providers/aws v0.0.0-20261003204812-9962786e0695 h1:DfNEBzFS7/MaBZljLGRRRUaarfnXXZyBE/6iozzp9/k=
-github.com/LeanerCloud/cloud-commitments-go/providers/aws v0.0.0-20261003204812-9962786e0695/go.mod h1:d4nsy61/Ptib0SxqMg0ble3yksVm3+QbtUtmGja82PA=
+github.com/LeanerCloud/cloud-commitments-go/pkg v0.0.0-20261004235520-de46f760cdcf h1:Q2MH8FZXpD9MdS/ZSExcjF7mTKxeQpoj96cY65ust1k=
+github.com/LeanerCloud/cloud-commitments-go/pkg v0.0.0-20261004235520-de46f760cdcf/go.mod h1:ApWBliDXe099f3oDXBz41K/I9v4bHvn1dG/BGoRmHlw=
+github.com/LeanerCloud/cloud-commitments-go/providers/aws v0.0.0-20261005004231-945a4045d11f h1:c3K60juwiY6t25Gr0HWAxajIDsXH4LzDO4e3ENGAsAM=
+github.com/LeanerCloud/cloud-commitments-go/providers/aws v0.0.0-20261005004231-945a4045d11f/go.mod h1:wpW9/TvGFUUOqBEleJL639loh6Ue5aVIcZKdubRnYPQ=
 github.com/LeanerCloud/cloud-commitments-go/providers/azure v0.0.0-20260928214714-ce9513612901 h1:iSdHYdmGUjcjtSmgGZxptBzDuLrJ9KR2mh1/x7FNvSY=
 github.com/LeanerCloud/cloud-commitments-go/providers/azure v0.0.0-20260928214714-ce9513612901/go.mod h1:zgCL/ozOkcZUDbEC7a2UwW+6MPcLoBlEU2WUZ0TORUs=
 github.com/LeanerCloud/cloud-commitments-go/providers/gcp v0.0.0-20260928214714-ce9513612901 h1:i6OwXLUheudN3GfwnYXdKuEq8vPdE9qkNJ+r71LRLKA=