Add error lookup test.

certification/hashtree/lookup_test.go

@@ -0,0 +1,44 @@
+package hashtree_test
+
+import (
+	"bytes"
+	"errors"
+	"github.com/aviate-labs/agent-go/certification/hashtree"
+	"testing"
+)
+
+func TestHashTree_Lookup_absent(t *testing.T) {
+	tree := hashtree.NewHashTree(hashtree.Labeled{
+		Label: hashtree.Label("a"),
+		Tree: hashtree.Labeled{
+			Label: hashtree.Label("b"),
+			Tree: hashtree.Labeled{
+				Label: hashtree.Label("c"),
+				Tree: hashtree.Fork{
+					LeftTree: hashtree.Labeled{
+						Label: hashtree.Label("d0"),
+					},
+					RightTree: hashtree.Labeled{
+						Label: hashtree.Label("d1"),
+						Tree:  hashtree.Leaf("d"),
+					},
+				},
+			},
+		},
+	})
+	var lookupError hashtree.LookupError
+	if _, err := tree.Lookup(hashtree.Label("a"), hashtree.Label("b"), hashtree.Label("c0"), hashtree.Label("d0")); !errors.As(err, &lookupError) || lookupError.Type != hashtree.LookupResultAbsent {
+		t.Fatalf("unexpected lookup result")
+	}
+	if _, err := tree.Lookup(hashtree.Label("a"), hashtree.Label("b"), hashtree.Label("c"), hashtree.Label("d0")); !errors.As(err, &lookupError) || lookupError.Type != hashtree.LookupResultAbsent {
+		t.Fatalf("unexpected lookup result")
+	}
+
+	v, err := tree.Lookup(hashtree.Label("a"), hashtree.Label("b"), hashtree.Label("c"), hashtree.Label("d1"))
+	if err != nil {
+		t.Fatalf("unexpected lookup result")
+	}
+	if !bytes.Equal(v, hashtree.Label("d")) {
+		t.Fatalf("unexpected node value")
+	}
+}