Derive stable prompt sessions for CLI runs

internal/cli/session_test.go

@@ -0,0 +1,61 @@
+package cli
+
+import "testing"
+
+func TestResolvePromptSessionIDUsesVersionedInputIdentity(t *testing.T) {
+	got, err := resolvePromptSessionID("", " seriatim/input/transcript ", []byte("{\"entries\":[\"one\"]}\n"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	const want = "notarius:v1:e15fefdca48653e73248b4157900547be1fd34250c0138f8d3d1f2e89b43bb25"
+	if got != want {
+		t.Fatalf("resolved session = %q, want %q", got, want)
+	}
+}
+
+func TestResolvePromptSessionIDStabilityAndOverride(t *testing.T) {
+	rawInput := []byte("same input")
+	baseline, err := resolvePromptSessionID("", "input/transcript", rawInput)
+	if err != nil {
+		t.Fatal(err)
+	}
+	repeated, err := resolvePromptSessionID("", "input/transcript", rawInput)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if baseline != repeated {
+		t.Fatalf("resolved sessions = %q and %q, want stable value", baseline, repeated)
+	}
+
+	differentModule, err := resolvePromptSessionID("", "input/other", rawInput)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if baseline == differentModule {
+		t.Fatalf("resolved sessions = %q for distinct input modules", baseline)
+	}
+
+	differentInput, err := resolvePromptSessionID("", "input/transcript", []byte("same inpuu"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if baseline == differentInput {
+		t.Fatalf("resolved sessions = %q for distinct input bytes", baseline)
+	}
+
+	override, err := resolvePromptSessionID(" explicit-session ", "input/other", []byte("different input"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if override != "explicit-session" {
+		t.Fatalf("resolved override = %q, want %q", override, "explicit-session")
+	}
+}
+
+func TestResolvePromptSessionIDRejectsEmptyInputModule(t *testing.T) {
+	for _, explicitSessionID := range []string{"", "explicit-session"} {
+		if _, err := resolvePromptSessionID(explicitSessionID, " \t", []byte("input")); err == nil {
+			t.Fatalf("resolvePromptSessionID(%q) error = nil, want empty module failure", explicitSessionID)
+		}
+	}
+}