From bfbc9110bfa0382340a0faf881e3605cf23dd71d Mon Sep 17 00:00:00 2001
From: Cristian Magherusan-Stanciu <cristi.magherusan@gmail.com>
Date: Thu, 28 May 2026 20:08:38 +0200
Subject: [PATCH] fix(azure/compute): ctx cancel terminal in SKU catalogue loop
 (closes #217)

Treat context.Canceled/DeadlineExceeded as hard stops in the
fetchSKUCatalogue pagination loop per feedback_ctx_cancel_terminal.md.
VCPU/MemoryGB fall back to 0 on cancellation, matching the existing
pager-error graceful-degradation contract.

New test pins the invariant: a pre-cancelled context skips all NextPage
calls and returns a nil catalogue.
---
 providers/azure/services/compute/client.go    |  8 +++--
 .../azure/services/compute/client_test.go     | 29 +++++++++++++++++++
 2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/providers/azure/services/compute/client.go b/providers/azure/services/compute/client.go
index 2b45d9a12..aeb974da9 100644
--- a/providers/azure/services/compute/client.go
+++ b/providers/azure/services/compute/client.go
@@ -798,9 +798,11 @@ func (c *ComputeClient) cachedSKULookup(ctx context.Context, skuName string) (vm
 // GetValidResourceTypes — a SKU listed for a different region is not
 // safe to attribute to a recommendation in this client's region).
 //
-// Returns nil on pager-create or page-fetch error so the
-// sync.Once-gated cache field stays nil and cachedSKULookup falls back
-// to the empty-fields path. The fetch error is logged WARN once.
+// Returns nil on pager-create, page-fetch error, or context cancellation
+// so the sync.Once-gated cache field stays nil and cachedSKULookup falls
+// back to the empty-fields path. Errors and cancellation are logged WARN
+// once; context.Canceled/DeadlineExceeded are treated as terminal
+// (feedback_ctx_cancel_terminal.md).
 func (c *ComputeClient) fetchSKUCatalogue(ctx context.Context) map[string]vmSKUEntry {
 	pager, err := c.createResourceSKUsPager()
 	if err != nil {
diff --git a/providers/azure/services/compute/client_test.go b/providers/azure/services/compute/client_test.go
index 579a81e29..6b991cd86 100644
--- a/providers/azure/services/compute/client_test.go
+++ b/providers/azure/services/compute/client_test.go
@@ -1083,6 +1083,35 @@ func TestComputeClient_ConvertAzureVMRecommendation_PagerErrorFallsBack(t *testi
 	assert.Equal(t, 0.0, details.MemoryGB, "MemoryGB left at 0 when catalogue fetch fails")
 }
 
+// TestComputeClient_FetchSKUCatalogue_CancelledContextFallsBack asserts
+// that a cancelled context is terminal in the SKU catalogue pagination
+// loop — the catalogue returns nil and Details.VCPU/MemoryGB stay at 0,
+// but the conversion itself succeeds (graceful-degradation contract).
+// Pins feedback_ctx_cancel_terminal.md for the compute SKU path.
+func TestComputeClient_FetchSKUCatalogue_CancelledContextFallsBack(t *testing.T) {
+	client := NewClient(nil, "test-subscription", "eastus")
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // cancel immediately so ctx.Err() is set on first loop iteration
+
+	mockPager := &vmSKUCatalogueMockPager{
+		pages: []armcompute.ResourceSKUsClientListResponse{
+			{
+				ResourceSKUsResult: armcompute.ResourceSKUsResult{
+					Value: []*armcompute.ResourceSKU{
+						buildVMSKU("Standard_D2s_v3", "eastus", 2, "8"),
+					},
+				},
+			},
+		},
+	}
+	client.SetResourceSKUsPager(mockPager)
+
+	result := client.fetchSKUCatalogue(ctx)
+	assert.Nil(t, result, "cancelled context must return nil catalogue")
+	assert.Equal(t, 0, mockPager.pageHits, "NextPage must not be called after context is already cancelled")
+}
+
 // TestComputeClient_ConvertAzureVMRecommendation_NoMatchLeavesFieldsZero
 // asserts that when the recommendation's SKU isn't in the catalogue
 // (e.g. SKU listed for another region only), VCPU/MemoryGB stay at 0