Targets section: one Add, then a type and Next, then its fields (closes #370)

The webhook page's targets section lists only its targets until Add is
clicked. Add shows a choice of target type with Next; Next shows only
that type's fields, with Save and Cancel. The `database` and `log`
types have no URL field, and the `slack` form gains max retries.

A refused target now shows the webhook page again with the form open on
its type, the values entered and the reason, instead of a bare text
page. Target validation returns that message rather than writing the
response; newTarget validates a whole new target for reuse by the
new-webhook page. The edit page still answers a refusal in plain text.

Model: opus-5-5

internal/handlers/target_create_test.go

@@ -0,0 +1,144 @@
+package handlers_test
+
+import (
+	"html"
+	"net/http"
+	"net/url"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+// TestHandleTargetCreate_EveryType adds a target of each type. Each
+// submission carries a url: only the http and slack types store one.
+func TestHandleTargetCreate_EveryType(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	// fields is the rest of each submission, as a query string.
+	cases := []struct {
+		targetType  database.TargetType
+		fields      string
+		wantConfig  string
+		wantRetries int
+	}{
+		{
+			database.TargetTypeHTTP, "timeout=12&max_retries=3",
+			`{"url":"` + editOriginalURL + `","timeout":12}`, 3,
+		},
+		{
+			database.TargetTypeSlack, "max_retries=4",
+			`{"webhookUrl":"` + editOriginalURL + `"}`, 4,
+		},
+		{
+			database.TargetTypeDatabase, "expiry=720h",
+			`{"expiry":"720h"}`, 0,
+		},
+		{database.TargetTypeLog, "", "", 0},
+	}
+
+	for _, tc := range cases {
+		t.Run(string(tc.targetType), func(t *testing.T) {
+			t.Parallel()
+
+			webhook := seedWebhookWithRetention(t, env.db, 30)
+
+			form, err := url.ParseQuery(tc.fields)
+			require.NoError(t, err)
+			form.Set("name", "every-type")
+			form.Set("type", string(tc.targetType))
+			form.Set("url", editOriginalURL)
+
+			w := serveTarget(
+				env, http.MethodPost,
+				"/hook/"+webhook.ID+"/targets", form,
+			)
+			require.Equal(t, http.StatusSeeOther, w.Code, w.Body.String())
+
+			targets := targetsForWebhook(t, env.db, webhook.ID)
+			require.Len(t, targets, 1)
+			assert.Equal(t, tc.targetType, targets[0].Type)
+			assert.Equal(t, tc.wantRetries, targets[0].MaxRetries)
+
+			if tc.wantConfig == "" {
+				assert.Empty(t, targets[0].Config)
+			} else {
+				assert.JSONEq(t, tc.wantConfig, targets[0].Config)
+			}
+		})
+	}
+}
+
+// TestHandleTargetCreate_RefusedFormComesBack refuses a target of each
+// type and checks that the webhook page comes back with the add target
+// form open on that type, the values entered, and the reason.
+func TestHandleTargetCreate_RefusedFormComesBack(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	// fields is what the operator typed, as a query string.
+	cases := []struct {
+		targetType database.TargetType
+		fields     string
+		reason     string
+	}{
+		{
+			database.TargetTypeHTTP,
+			"name=private&url=" + editBlockedURL +
+				"&timeout=12&max_retries=3",
+			"Invalid target URL",
+		},
+		{
+			database.TargetTypeSlack, "name=no-url&max_retries=4",
+			"Webhook URL is required for Slack targets",
+		},
+		{
+			database.TargetTypeDatabase, "name=archive&expiry=7d",
+			"Invalid archive expiry",
+		},
+		{database.TargetTypeLog, "name=", "Name is required"},
+	}
+
+	for _, tc := range cases {
+		t.Run(string(tc.targetType), func(t *testing.T) {
+			t.Parallel()
+
+			webhook := seedWebhookWithRetention(t, env.db, 30)
+
+			typed, err := url.ParseQuery(tc.fields)
+			require.NoError(t, err)
+
+			form := url.Values{}
+			form.Set("type", string(tc.targetType))
+
+			for field := range typed {
+				form.Set(field, typed.Get(field))
+			}
+
+			w := serveTarget(
+				env, http.MethodPost,
+				"/hook/"+webhook.ID+"/targets", form,
+			)
+			assert.Equal(t, http.StatusBadRequest, w.Code)
+
+			page := w.Body.String()
+			assert.Contains(
+				t, page, `data-type="`+string(tc.targetType)+`"`,
+			)
+			assert.Contains(t, page, html.EscapeString(tc.reason))
+
+			for field := range typed {
+				assert.Contains(
+					t, page, `name="`+field+`" value="`+
+						html.EscapeString(typed.Get(field))+`"`,
+				)
+			}
+
+			assert.Empty(t, targetsForWebhook(t, env.db, webhook.ID))
+		})
+	}
+}