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

[Somilg11]

Description

harbor webhook list panics with an index-out-of-range error whenever Harbor returns a webhook policy with an empty targets array. The list view indexed webhook.Targets[0] unconditionally, but targets is optional in the generated WebhookPolicy model, so a policy without targets crashes the command instead of
rendering.

cmd/harbor/root/webhook/edit.go:146 already guards len(Targets) > 0, so the list view was the only unguarded access left.

• Fixes [bug]: webhook list panics when a policy has no targets #973

Type of Change

Please select the relevant type.

• Bug fix
• New feature
• Refactor
• Documentation update
• Chore / maintenance

Changes

• Extract row construction from ListWebhooks into a testable webhookRows helper.
• Fall back to a -- placeholder for Endpoint URL, Notify Type and Payload Format when the first target is missing, nil, or has empty fields.
• Skip nil policies instead of dereferencing them.
• Add unit tests covering: policy with a target, policy with no targets, nil target in the slice, target with empty fields, nil policy, and cell/column arity.

No behaviour change for policies that do have a target — the same values render as before.

Testing

Reproduction

Harbor rejects a webhook policy with no target at create time, but targets is optional in the generated WebhookPolicy model — which is why edit.go already guards it. I reproduced the response shape with a small stub server returning "targets": [] for GET /api/v2.0/projects/demo/webhook/policies, serving two
policies: broken-hook (no targets) and healthy-hook (a normal target), so a single run exercises both the crash case and the unaffected case.

Before (main) — harbor webhook list demo panics at pkg/views/webhook/list/view.go:48:

After (this branch) — same stub, same command. broken-hook renders with --
placeholders; healthy-hook renders exactly as before:

Unit tests

The code-level repro from the issue (&models.WebhookPolicy{}) is covered as a permanent regression guard:

go test ./pkg/views/webhook/... -v -run TestWebhookRows -count=1

Full suite passes: go build ./..., go vet ./pkg/views/webhook/..., go test ./....