Tell mesh-config what a head declares at every head, so a head that reverts a key drops its held value (issue 1826)

cmd/mesh-controller/pull_declares_test.go

@@ -98,8 +98,9 @@ func TestAnUnchangedKeyIsNotToldAndAChangedOneIs(t *testing.T) {
 	}
 }
 
-// 1826/AC1: a pull request that changes no module.json, or removes it, tells mesh-config nothing.
-func TestAPullRequestThatDeclaresNothingSendsNothing(t *testing.T) {
+// 1826/AC1: a head that changes no module.json, or removes it, is still told, with declares {}: mesh-config re-judges at every
+// head, so a head that reverts the change drops the value held for it (review round 1, finding 1).
+func TestAHeadThatDeclaresNothingIsToldAsEmpty(t *testing.T) {
 	fakeManifests(t, map[string]*catalogue.Manifest{baseSHA: manifest("n8n", nil), headSHA: manifest("n8n", nil)})
 	calls := fakeConfig(t, nil)
 	p := thePull()
@@ -108,9 +109,25 @@ func TestAPullRequestThatDeclaresNothingSendsNothing(t *testing.T) {
 	p = thePull()
 	p.Removed = p.Paths
 	tellPullDeclares(context.Background(), io.Discard, []pullAt{p})
-	if len(*calls) != 0 {
+	if len(*calls) != 2 {
 		t.Fatalf("mesh-config was told %v", *calls)
 	}
+	for _, c := range *calls {
+		if d, _ := json.Marshal(c["declares"]); string(d) != "{}" || c["head"] != headSHA {
+			t.Fatalf("told %v", c)
+		}
+	}
+}
+
+// 1826/AC1: a head whose paths are cut, or whose base is unknown, cannot be read: nothing is told, never an empty set.
+func TestAHeadThatCannotBeReadIsNotToldAsEmpty(t *testing.T) {
+	calls := fakeConfig(t, nil)
+	p := thePull()
+	p.Truncated = true
+	tellPullDeclares(context.Background(), io.Discard, []pullAt{p})
+	if len(*calls) != 0 {
+		t.Fatalf("told %v", *calls)
+	}
 }
 
 // 1826/AC1: a module.json changed without a declaration changing is told as an empty set, so mesh-config re-judges what it holds.
@@ -182,3 +199,11 @@ func TestTheCheckRequestCarriesTheHeldValues(t *testing.T) {
 		t.Fatalf("a composed member carries %+v", request.Check.HeldConfig)
 	}
 }
+
+// 1826/AC1: a repository that builds a module of the mesh holds modules; another does not.
+func TestARepositoryThatBuildsAModuleHoldsModules(t *testing.T) {
+	entries := []inventory.Entry{{Manifest: catalogue.Manifest{Module: "a"}, Source: inventory.Source{Repository: "novox/mesh-catalog", Path: "modules/a"}}}
+	if !holdsModules(entries, "novox", "mesh-catalog") || holdsModules(entries, "novox", "hq") {
+		t.Fatal("wrong")
+	}
+}