From 1319432e55ab03dd43f3e1836d8bf37aca980463 Mon Sep 17 00:00:00 2001
From: jochen <jschoubben@gmail.com>
Date: Wed, 21 Oct 2026 21:49:37 +0200
Subject: [PATCH] Test that the integration level gets MESH_CHECK_BESIDE only
 when siblings were placed (issue 1677)

---
 .../cmd/mesh-build-go/preview_test.go         | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/modules/mesh-build-go/cmd/mesh-build-go/preview_test.go b/modules/mesh-build-go/cmd/mesh-build-go/preview_test.go
index 78b19943..2fcee7ea 100644
--- a/modules/mesh-build-go/cmd/mesh-build-go/preview_test.go
+++ b/modules/mesh-build-go/cmd/mesh-build-go/preview_test.go
@@ -272,3 +272,46 @@ func TestPackagesRunOnlyInTheModuleThatHoldsThem(t *testing.T) {
 }
 
 func sha256Hex(b []byte) string { h := sha256.Sum256(b); return hex.EncodeToString(h[:]) }
+
+// 1677/AC (integration level): the integration level's go test is given MESH_CHECK_BESIDE when the workspace has siblings
+// beside it, with the store's and the bus's addresses, and is given none when it has not.
+func TestTheIntegrationLevelIsGivenTheBesideDirectoryOnlyWhenSiblingsWerePlaced(t *testing.T) {
+	for _, siblings := range []bool{true, false} {
+		f := newIntegFake(t, "slow")
+		m, states := integModule(t, f)
+		beside := filepath.Join(m.Work, "ws1", "beside")
+		if siblings {
+			if err := os.MkdirAll(filepath.Join(beside, "mesh-catalog"), 0o755); err != nil {
+				t.Fatal(err)
+			}
+		}
+		if _, st := runLevelTool(t, m, states, "integration"); st.State != delivery.StepPassed {
+			t.Fatalf("the step ended %s: %s", st.State, st.Reason)
+		}
+		tested := 0
+		for _, c := range f.calls {
+			if !strings.HasPrefix(c.line, "go ") || !strings.Contains(c.line, "-tags integration") {
+				continue
+			}
+			tested++
+			got := ""
+			hasNATS := false
+			for _, e := range c.env {
+				if strings.HasPrefix(e, "MESH_CHECK_BESIDE=") {
+					got = strings.TrimPrefix(e, "MESH_CHECK_BESIDE=")
+				}
+				hasNATS = hasNATS || strings.HasPrefix(e, "MESH_TEST_NATS=")
+			}
+			want := ""
+			if siblings {
+				want = beside
+			}
+			if got != want || !hasNATS {
+				t.Errorf("siblings %v: %s was given MESH_CHECK_BESIDE=%q (want %q), MESH_TEST_NATS present %v", siblings, c.line, got, want, hasNATS)
+			}
+		}
+		if tested == 0 {
+			t.Errorf("siblings %v: no integration go test ran", siblings)
+		}
+	}
+}