test(server): Decompose base URL to URI to helper and add test (#3839)

Decompose the logic for parsing base URL into the URI for client dial.
Add a unit test for the new helper.

repo/grpc_repository_client.go

@@ -829,18 +829,9 @@ func openGRPCAPIRepository(ctx context.Context, si *APIServerInfo, password stri
 		transportCreds = credentials.NewClientTLSFromCert(nil, "")
 	}
 
-	u, err := url.Parse(si.BaseURL)
+	uri, err := baseURLToURI(si.BaseURL)
 	if err != nil {
-		return nil, errors.Wrap(err, "unable to parse server URL")
-	}
-
-	if u.Scheme != "kopia" && u.Scheme != "https" && u.Scheme != "unix+https" {
-		return nil, errors.Errorf("invalid server address, must be 'https://host:port' or 'unix+https://<path>")
-	}
-
-	uri := net.JoinHostPort(u.Hostname(), u.Port())
-	if u.Scheme == "unix+https" {
-		uri = "unix:" + u.Path
+		return nil, errors.Wrap(err, "parsing base URL")
 	}
 
 	conn, err := grpc.NewClient(
@@ -869,6 +860,24 @@ func openGRPCAPIRepository(ctx context.Context, si *APIServerInfo, password stri
 	return rep, nil
 }
 
+func baseURLToURI(baseURL string) (uri string, err error) {
+	u, err := url.Parse(baseURL)
+	if err != nil {
+		return "", errors.Wrap(err, "unable to parse server URL")
+	}
+
+	if u.Scheme != "kopia" && u.Scheme != "https" && u.Scheme != "unix+https" {
+		return "", errors.Errorf("invalid server address, must be 'https://host:port' or 'unix+https://<path>")
+	}
+
+	uri = net.JoinHostPort(u.Hostname(), u.Port())
+	if u.Scheme == "unix+https" {
+		uri = "unix:" + u.Path
+	}
+
+	return uri, nil
+}
+
 func (r *grpcRepositoryClient) getOrEstablishInnerSession(ctx context.Context) (*grpcInnerSession, error) {
 	r.innerSessionMutex.Lock()
 	defer r.innerSessionMutex.Unlock()

repo/grpc_repository_client_unit_test.go

@@ -0,0 +1,64 @@
+package repo
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestBaseURLToURI(t *testing.T) {
+	for _, tc := range []struct {
+		name      string
+		baseURL   string
+		expURI    string
+		expErrMsg string
+	}{
+		{
+			name:      "ipv4",
+			baseURL:   "https://1.2.3.4:5678",
+			expURI:    "1.2.3.4:5678",
+			expErrMsg: "",
+		},
+		{
+			name:      "ipv6",
+			baseURL:   "https://[2600:1f14:253f:ef00:87b9::10]:51515",
+			expURI:    "[2600:1f14:253f:ef00:87b9::10]:51515",
+			expErrMsg: "",
+		},
+		{
+			name:      "unix https scheme",
+			baseURL:   "unix+https:///tmp/kopia-test606141450/sock",
+			expURI:    "unix:/tmp/kopia-test606141450/sock",
+			expErrMsg: "",
+		},
+		{
+			name:      "kopia scheme",
+			baseURL:   "kopia://a:0",
+			expURI:    "a:0",
+			expErrMsg: "",
+		},
+		{
+			name:      "unix http scheme is invalid",
+			baseURL:   "unix+http:///tmp/kopia-test606141450/sock",
+			expURI:    "",
+			expErrMsg: "invalid server address",
+		},
+		{
+			name:      "invalid address",
+			baseURL:   "a",
+			expURI:    "",
+			expErrMsg: "invalid server address",
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			gotURI, err := baseURLToURI(tc.baseURL)
+			if tc.expErrMsg != "" {
+				require.ErrorContains(t, err, tc.expErrMsg)
+				return
+			}
+
+			require.NoError(t, err)
+			require.Equal(t, tc.expURI, gotURI)
+		})
+	}
+}