Show missing OAuth scopes after connector reconnect

Partial grants completed without feedback, leaving Reconnect
required unexplained. Keep the token and toast the backend
missing-scopes error after the OAuth callback redirect.

Signed-off-by: Sacha Al Himdani <sacha@probo.com>

pkg/accessreview/source_missing_scopes_test.go

@@ -0,0 +1,112 @@
+// Copyright (c) 2026 Probo Inc <hello@probo.com>.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package accessreview
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.probo.inc/probo/pkg/connector"
+	"go.probo.inc/probo/pkg/coredata"
+)
+
+func TestMissingOAuthScopesForConnector(t *testing.T) {
+	t.Parallel()
+
+	required := []string{
+		"openid",
+		"https://graph.microsoft.com/AuditLog.Read.All",
+		"https://graph.microsoft.com/User.Read.All",
+	}
+
+	t.Run("non oauth protocol returns empty", func(t *testing.T) {
+		t.Parallel()
+
+		dbConnector := coredata.Connector{
+			Protocol:   coredata.ConnectorProtocolAPIKey,
+			Connection: &connector.APIKeyConnection{APIKey: "k"},
+		}
+
+		assert.Empty(t, missingOAuthScopesForConnector(dbConnector, required))
+	})
+
+	t.Run("empty required returns empty", func(t *testing.T) {
+		t.Parallel()
+
+		dbConnector := coredata.Connector{
+			Protocol: coredata.ConnectorProtocolOAuth2,
+			Connection: &connector.OAuth2Connection{
+				Scope: "openid",
+			},
+		}
+
+		assert.Empty(t, missingOAuthScopesForConnector(dbConnector, nil))
+	})
+
+	t.Run("nil connection treats grant as empty", func(t *testing.T) {
+		t.Parallel()
+
+		dbConnector := coredata.Connector{
+			Protocol:   coredata.ConnectorProtocolOAuth2,
+			Connection: nil,
+		}
+
+		assert.Equal(
+			t,
+			[]string{
+				"https://graph.microsoft.com/AuditLog.Read.All",
+				"https://graph.microsoft.com/User.Read.All",
+				"openid",
+			},
+			missingOAuthScopesForConnector(dbConnector, required),
+		)
+	})
+
+	t.Run("partial grant returns missing scopes", func(t *testing.T) {
+		t.Parallel()
+
+		dbConnector := coredata.Connector{
+			Protocol: coredata.ConnectorProtocolOAuth2,
+			Connection: &connector.OAuth2Connection{
+				Scope: "openid User.Read.All",
+			},
+		}
+
+		assert.Equal(
+			t,
+			[]string{"https://graph.microsoft.com/AuditLog.Read.All"},
+			missingOAuthScopesForConnector(dbConnector, required),
+		)
+	})
+
+	t.Run("full grant returns empty", func(t *testing.T) {
+		t.Parallel()
+
+		dbConnector := coredata.Connector{
+			Protocol: coredata.ConnectorProtocolOAuth2,
+			Connection: &connector.OAuth2Connection{
+				Scope: "openid AuditLog.Read.All User.Read.All",
+			},
+		}
+
+		assert.Empty(t, missingOAuthScopesForConnector(dbConnector, required))
+	})
+}