Fold the composer key's versions test into the existing key test: mesh-sdk is over its test budget (issue 1921)

Claude-Session: https://claude.ai/code/session_01NcbgfFSnn24M3GcqttoU7i

go/delivery/stepasks.go

@@ -310,9 +310,19 @@ type ComposeAnswer struct {
 
 // ComposerKey is the key a build module keeps a built composer under: the repository, commit, directory and package it
 // was built from and the toolchain it was built with, hashed (`composer-` and 16 hex digits), so each head is built once
-// on a node (ADR 0482 clause 4).
-func ComposerKey(repository, commit, dir, pkg string, toolchain ToolchainUsed) string {
-	sum := sha256.Sum256([]byte(strings.Join([]string{repository, commit, dir, pkg, toolchain.Version, toolchain.Recipe}, "\n")))
+// on a node (ADR 0482 clause 4). The mesh package versions the ask names are an input of the build, so they are in the
+// key, sorted, when there are any; an ask that names none gets the key it always had (issue 1921).
+func ComposerKey(repository, commit, dir, pkg string, toolchain ToolchainUsed, versions PackageVersions) string {
+	parts := []string{repository, commit, dir, pkg, toolchain.Version, toolchain.Recipe}
+	pkgs := make([]string, 0, len(versions))
+	for p := range versions {
+		pkgs = append(pkgs, p)
+	}
+	sort.Strings(pkgs)
+	for _, p := range pkgs {
+		parts = append(parts, p+"="+versions[p])
+	}
+	sum := sha256.Sum256([]byte(strings.Join(parts, "\n")))
 	return "composer-" + hex.EncodeToString(sum[:8])
 }
 

go/delivery/stepasks_compose_test.go

@@ -56,21 +56,34 @@ func TestAComposeAskIsRefusedWhereItDoesNotBelong(t *testing.T) {
 	}
 }
 
-// 1622/AC3: a composer is kept under one key per repository, commit, directory, package and toolchain, so two asks of
+// 1622/AC3, 1921: a composer is kept under one key per repository, commit, directory, package, toolchain and asked versions, so two asks of
 // one head build it once on a node, and another head or toolchain builds its own.
 func TestAComposerIsKeptByWhatItWasBuiltFrom(t *testing.T) {
 	tc := ToolchainUsed{Version: "go1.26.0", Recipe: "3"}
-	k := ComposerKey("novox/mesh-sdk", askCommit, "go", "p", tc)
-	if k != ComposerKey("novox/mesh-sdk", askCommit, "go", "p", tc) || !strings.HasPrefix(k, "composer-") || len(k) != len("composer-")+16 {
+	k := ComposerKey("novox/mesh-sdk", askCommit, "go", "p", tc, nil)
+	if k != ComposerKey("novox/mesh-sdk", askCommit, "go", "p", tc, nil) || !strings.HasPrefix(k, "composer-") || len(k) != len("composer-")+16 {
 		t.Fatalf("key = %q", k)
 	}
 	for _, other := range []string{
-		ComposerKey("novox/mesh-sdk", strings.Repeat("1", 40), "go", "p", tc),
-		ComposerKey("novox/mesh-controller", askCommit, ".", "p", tc),
-		ComposerKey("novox/mesh-sdk", askCommit, "go", "p", ToolchainUsed{Version: "go1.26.1", Recipe: "3"}),
+		ComposerKey("novox/mesh-sdk", strings.Repeat("1", 40), "go", "p", tc, nil),
+		ComposerKey("novox/mesh-controller", askCommit, ".", "p", tc, nil),
+		ComposerKey("novox/mesh-sdk", askCommit, "go", "p", ToolchainUsed{Version: "go1.26.1", Recipe: "3"}, nil),
+		ComposerKey("novox/mesh-sdk", askCommit, "go", "p", tc, PackageVersions{"git.novox.be/novox/mesh-sdk/go": strings.Repeat("2", 40)}),
 	} {
 		if other == k {
 			t.Errorf("two composers built from different inputs share the key %s", k)
 		}
 	}
+	// 1921: the asked versions are in the key, in any order of naming; none, or an empty ask, gives the key without them.
+	a, b := strings.Repeat("a", 40), strings.Repeat("b", 40)
+	k1 := ComposerKey("r", askCommit, "go", "p", tc, PackageVersions{"m/x": a, "m/y": b})
+	if k1 != ComposerKey("r", askCommit, "go", "p", tc, PackageVersions{"m/y": b, "m/x": a}) {
+		t.Error("the key depends on the order of the versions")
+	}
+	if k1 == ComposerKey("r", askCommit, "go", "p", tc, PackageVersions{"m/x": b, "m/y": a}) || k1 == ComposerKey("r", askCommit, "go", "p", tc, nil) {
+		t.Error("other versions, or none, share the key")
+	}
+	if ComposerKey("r", askCommit, "go", "p", tc, nil) != ComposerKey("r", askCommit, "go", "p", tc, PackageVersions{}) {
+		t.Error("an empty ask changed the key")
+	}
 }