Add item registry domain foundation

internal/modules/dnd/items/identity/identity_test.go

@@ -0,0 +1,89 @@
+package identity
+
+import (
+	"encoding/json"
+	"reflect"
+	"strings"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/modules/dnd"
+)
+
+func TestComparisonKeyNormalizesSupportedEquivalences(t *testing.T) {
+	tests := []struct {
+		name  string
+		left  string
+		right string
+	}{
+		{name: "case", left: "Silver Key", right: "sILVER kEY"},
+		{name: "compatibility", left: "Ｓｉｌｖｅｒ Ｋｅｙ", right: "Silver Key"},
+		{name: "whitespace", left: "  Silver\u2003Key ", right: "Silver Key"},
+		{name: "apostrophe", left: "Healer’s Kit", right: "healer's kit"},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if ComparisonKey(test.left) != ComparisonKey(test.right) {
+				t.Fatalf("ComparisonKey(%q) = %q, ComparisonKey(%q) = %q", test.left, ComparisonKey(test.left), test.right, ComparisonKey(test.right))
+			}
+		})
+	}
+	if ComparisonKey("Silver Key") == ComparisonKey("Gold Key") {
+		t.Fatal("different item types received the same comparison key")
+	}
+}
+
+func TestDeriveIDUsesExactCompactIdentityBytes(t *testing.T) {
+	const wantID = "item:sha256:2f211c60b9bdcf3a6dd64086cc4c05df5b3357ae02cb462f7ef8988d9bd2fa4f"
+	const wantIdentity = `["dnd.item_registry.identity.v1","silver key"]`
+
+	encoded, err := json.Marshal([]string{Policy, ComparisonKey("Silver Key")})
+	if err != nil || string(encoded) != wantIdentity {
+		t.Fatalf("identity bytes = %q, %v; want %s", encoded, err, wantIdentity)
+	}
+	if Policy != "dnd.item_registry.identity.v1" || IdentityPolicy != Policy {
+		t.Fatalf("identity policy = %q/%q", Policy, IdentityPolicy)
+	}
+	if got := DeriveID("  SILVER\u2003KEY "); got != wantID || !IsValidID(got) || got != IDFor("Silver Key") {
+		t.Fatalf("DeriveID() = %q, want %q", got, wantID)
+	}
+	if DeriveID(" \u2003 ") != "" {
+		t.Fatal("empty identity produced an ID")
+	}
+	for _, invalid := range []string{"", "item:sha256:", "item:sha256:ABC", "item:sha256:" + strings.Repeat("0", 63), "item:sha256:" + strings.Repeat("0", 65)} {
+		if IsValidID(invalid) {
+			t.Fatalf("IsValidID(%q) = true, want false", invalid)
+		}
+	}
+}
+
+func TestValidateRegistryReportsDeterministicIdentityProblemsWithoutMutation(t *testing.T) {
+	items := []dnd.Item{
+		{ID: DeriveID("Silver Key"), Name: "Silver Key"},
+		{ID: DeriveID("Silver Key"), Name: " silver key "},
+		{ID: "bad", Name: "Gold Key"},
+		{ID: DeriveID("Silver Key"), Name: "Healer's Kit"},
+		{ID: "", Name: " "},
+	}
+	before := append([]dnd.Item(nil), items...)
+	issues := ValidateRegistry(items)
+	if !reflect.DeepEqual(items, before) {
+		t.Fatal("ValidateRegistry() mutated its input")
+	}
+
+	want := []IssueCode{
+		IssueDuplicateCanonical,
+		IssueDuplicateID,
+		IssueInvalidID,
+		IssueIDMismatch,
+		IssueEmptyCanonicalName,
+	}
+	seen := make(map[IssueCode]bool)
+	for _, issue := range issues {
+		seen[issue.Code] = true
+	}
+	for _, code := range want {
+		if !seen[code] {
+			t.Errorf("ValidateRegistry() issues = %#v, missing %s", issues, code)
+		}
+	}
+}