fix(webhook): render placeholders when a webhook policy has no targets

harbor webhook list panicked with an index-out-of-range error whenever
Harbor returned a webhook policy with an empty targets array. The list
view indexed Targets[0] unconditionally, but targets is optional in the
generated WebhookPolicy model.

Extract row construction into webhookRows and fall back to a placeholder
for the endpoint URL, notify type and payload format when the target is
missing, nil or empty. Nil policies are skipped rather than dereferenced.

Fixes #973

Signed-off-by: Somil Gupta <gsomil93@gmail.com>

Author: Somilg11

pkg/views/webhook/list/view.go

@@ -35,34 +35,61 @@ var columns = []table.Column{
 	{Title: "Creation Time", Width: 20},
 }
 
+// placeholder is shown whenever a webhook policy does not carry the target
+// details Harbor optionally omits from the response.
+const placeholder = "--"
+
 func ListWebhooks(webhooks []*models.WebhookPolicy) {
+	rows := webhookRows(webhooks)
+	m := tablelist.NewModel(columns, rows, len(rows))
+
+	if _, err := tea.NewProgram(m).Run(); err != nil {
+		fmt.Println("Error running program:", err)
+		os.Exit(1)
+	}
+}
+
+// webhookRows renders the table rows for the given policies. Targets are
+// optional in the Harbor API model, so a policy without any target still
+// yields a row with placeholders instead of panicking.
+func webhookRows(webhooks []*models.WebhookPolicy) []table.Row {
 	var rows []table.Row
 	for _, webhook := range webhooks {
-		var webhookEnabled string
+		if webhook == nil {
+			continue
+		}
+
+		webhookEnabled := "False"
 		if webhook.Enabled {
 			webhookEnabled = "True"
-		} else {
-			webhookEnabled = "False"
 		}
-		payloadFormat := "--"
-		if len(webhook.Targets[0].PayloadFormat) != 0 {
-			payloadFormat = string(webhook.Targets[0].PayloadFormat)
+
+		endpointURL, notifyType := placeholder, placeholder
+		payloadFormat := placeholder
+		if len(webhook.Targets) > 0 && webhook.Targets[0] != nil {
+			target := webhook.Targets[0]
+			if target.Address != "" {
+				endpointURL = target.Address
+			}
+			if target.Type != "" {
+				notifyType = target.Type
+			}
+			if target.PayloadFormat != "" {
+				payloadFormat = string(target.PayloadFormat)
+			}
 		}
+
 		creationTime, _ := utils.FormatCreatedTime(webhook.CreationTime.String())
 		rows = append(rows, table.Row{
 			strconv.FormatInt(webhook.ID, 10),
 			webhook.Name,
 			webhookEnabled,
-			webhook.Targets[0].Address,
-			webhook.Targets[0].Type,
+			endpointURL,
+			notifyType,
 			payloadFormat,
 			creationTime,
 		})
 	}
-	m := tablelist.NewModel(columns, rows, len(rows))
 
-	if _, err := tea.NewProgram(m).Run(); err != nil {
-		fmt.Println("Error running program:", err)
-		os.Exit(1)
-	}
+	return rows
 }

pkg/views/webhook/list/view_test.go

@@ -0,0 +1,103 @@
+// Copyright Project Harbor Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package list
+
+import (
+	"testing"
+
+	"github.com/goharbor/go-client/pkg/sdk/v2.0/models"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWebhookRows(t *testing.T) {
+	t.Run("policy with a target", func(t *testing.T) {
+		rows := webhookRows([]*models.WebhookPolicy{
+			{
+				ID:      1,
+				Name:    "hook",
+				Enabled: true,
+				Targets: []*models.WebhookTargetObject{
+					{
+						Address:       "https://example.com/hook",
+						Type:          "http",
+						PayloadFormat: models.PayloadFormatType("CloudEvents"),
+					},
+				},
+			},
+		})
+
+		require.Len(t, rows, 1)
+		assert.Equal(t, "1", rows[0][0])
+		assert.Equal(t, "hook", rows[0][1])
+		assert.Equal(t, "True", rows[0][2])
+		assert.Equal(t, "https://example.com/hook", rows[0][3])
+		assert.Equal(t, "http", rows[0][4])
+		assert.Equal(t, "CloudEvents", rows[0][5])
+	})
+
+	t.Run("policy without targets falls back to placeholders", func(t *testing.T) {
+		rows := webhookRows([]*models.WebhookPolicy{
+			{ID: 2, Name: "no-targets"},
+		})
+
+		require.Len(t, rows, 1)
+		assert.Equal(t, "2", rows[0][0])
+		assert.Equal(t, "no-targets", rows[0][1])
+		assert.Equal(t, "False", rows[0][2])
+		assert.Equal(t, placeholder, rows[0][3])
+		assert.Equal(t, placeholder, rows[0][4])
+		assert.Equal(t, placeholder, rows[0][5])
+	})
+
+	t.Run("policy with a nil target falls back to placeholders", func(t *testing.T) {
+		rows := webhookRows([]*models.WebhookPolicy{
+			{ID: 3, Name: "nil-target", Targets: []*models.WebhookTargetObject{nil}},
+		})
+
+		require.Len(t, rows, 1)
+		assert.Equal(t, placeholder, rows[0][3])
+		assert.Equal(t, placeholder, rows[0][4])
+		assert.Equal(t, placeholder, rows[0][5])
+	})
+
+	t.Run("target with empty fields falls back to placeholders", func(t *testing.T) {
+		rows := webhookRows([]*models.WebhookPolicy{
+			{ID: 4, Name: "empty-target", Targets: []*models.WebhookTargetObject{{}}},
+		})
+
+		require.Len(t, rows, 1)
+		assert.Equal(t, placeholder, rows[0][3])
+		assert.Equal(t, placeholder, rows[0][4])
+		assert.Equal(t, placeholder, rows[0][5])
+	})
+
+	t.Run("nil policies are skipped", func(t *testing.T) {
+		rows := webhookRows([]*models.WebhookPolicy{nil, {ID: 5, Name: "kept"}})
+
+		require.Len(t, rows, 1)
+		assert.Equal(t, "kept", rows[0][1])
+	})
+
+	t.Run("row has one cell per column", func(t *testing.T) {
+		rows := webhookRows([]*models.WebhookPolicy{{ID: 6}})
+
+		require.Len(t, rows, 1)
+		assert.Len(t, rows[0], len(columns))
+	})
+
+	t.Run("no policies yields no rows", func(t *testing.T) {
+		assert.Empty(t, webhookRows(nil))
+	})
+}