Keep what was typed when a target or webhook edit is refused (closes #381)

A refused save on the target edit page answered with a bare text page, losing the form and everything typed, and the webhook edit page came back with the stored values instead of the submitted ones. A refused target edit now shows the edit form again with the reason above it and every value submitted, with the same status codes as before; a refused webhook edit keeps the submitted name, description and retention. Target edits use the same validation as new targets, with no second copy; an encoding or database failure stays a logged 500. The browser test covers a refused save on both pages, and its main function is now a plain list of checks.

Model: opus-5-5

internal/handlers/source_management.go

@@ -616,13 +616,13 @@ func (h *Handlers) renderSourceDetail(
 		// Targets are projected to a display-safe view: a
 		// target's stored config blob holds a credential, and it
 		// must never reach a template.
-		"Entrypoints": entrypointViews,
-		"Targets":     h.targetRows(&webhook, targets),
-		"Events":      events,
-		"BaseURL":     baseURL,
-		"Stats":       h.loadWebhookStats(webhook.ID, entrypoints, targets),
-		"TargetForm":  targetForm,
-		"TargetError": targetErr,
+		"Entrypoints":     entrypointViews,
+		"Targets":         h.targetRows(&webhook, targets),
+		"Events":          events,
+		"BaseURL":         baseURL,
+		"Stats":           h.loadWebhookStats(webhook.ID, entrypoints, targets),
+		tmplKeyTargetForm: targetForm,
+		"TargetError":     targetErr,
 	}
 
 	status := http.StatusOK
@@ -658,12 +658,12 @@ func (h *Handlers) HandleSourceEdit() http.HandlerFunc {
 			return
 		}
 
-		data := map[string]any{
-			tmplKeyWebhook: &webhook,
-			tmplKeyError:   "",
-		}
-
-		h.renderTemplate(w, r, "source_edit.html", data)
+		h.renderWebhookEdit(
+			w, r, &webhook,
+			webhook.Name, webhook.Description,
+			strconv.Itoa(webhook.RetentionDays),
+			"", http.StatusOK,
+		)
 	}
 }
 
@@ -709,7 +709,8 @@ func (h *Handlers) HandleSourceEditSubmit() http.HandlerFunc {
 	}
 }
 
-// applyWebhookEdit validates and saves webhook edits.
+// applyWebhookEdit validates and saves webhook edits. A refused save
+// shows the edit form again with the values submitted and the reason.
 func (h *Handlers) applyWebhookEdit(
 	w http.ResponseWriter,
 	r *http.Request,
@@ -718,52 +719,52 @@ func (h *Handlers) applyWebhookEdit(
 	// The body size cap is enforced by the MaxBodySize middleware,
 	// which runs before CSRF parses the form.
 	name := r.PostFormValue("name")
-	if name == "" {
-		data := map[string]any{
-			tmplKeyWebhook: webhook,
-			tmplKeyError:   "Name is required",
-		}
+	description := r.PostFormValue("description")
+	retention := r.PostFormValue("retention_days")
 
-		h.renderTemplateStatus(w, r, "source_edit.html", data, http.StatusBadRequest)
+	if name == "" {
+		h.renderWebhookEdit(
+			w, r, webhook, name, description, retention,
+			"Name is required", http.StatusBadRequest,
+		)
 
 		return
 	}
 
-	oldName := webhook.Name
-	webhook.Name = name
-	webhook.Description = r.PostFormValue("description")
-
 	// An empty field falls back to the stored value, so submitting the
 	// form without touching retention leaves the policy alone.
 	retentionDays, errMsg := parseRetentionDays(
-		r.PostFormValue("retention_days"), webhook.RetentionDays,
+		retention, webhook.RetentionDays,
 	)
 	if errMsg != "" {
-		data := map[string]any{
-			tmplKeyWebhook: webhook,
-			tmplKeyError:   errMsg,
-		}
-
-		h.renderTemplateStatus(w, r, "source_edit.html", data, http.StatusBadRequest)
+		h.renderWebhookEdit(
+			w, r, webhook, name, description, retention,
+			errMsg, http.StatusBadRequest,
+		)
 
 		return
 	}
 
-	webhook.RetentionDays = retentionDays
+	// edited is the webhook as the submission leaves it; webhook stays
+	// as stored, for the page shown again when the save is refused.
+	edited := *webhook
+	edited.Name = name
+	edited.Description = description
+	edited.RetentionDays = retentionDays
 
 	// A new name renames the archive files before it is saved (see
 	// delivery.Engine.Rename). If either step fails, the same targets'
 	// archives go back to the name that is still stored, without
 	// reading the main database again.
 	targets, err := h.renameWebhookArchives(
-		webhook.ID, oldName, webhook.Name,
+		webhook.ID, webhook.Name, edited.Name,
 	)
 	if err == nil {
-		err = h.db.DB().Save(webhook).Error
+		err = h.db.DB().Save(&edited).Error
 	}
 
 	if err != nil {
-		restoreErr := h.renameArchives(targets, oldName)
+		restoreErr := h.renameArchives(targets, webhook.Name)
 		if restoreErr != nil {
 			h.log.Error(
 				"failed to rename archives back",
@@ -773,15 +774,14 @@ func (h *Handlers) applyWebhookEdit(
 		}
 
 		if errors.Is(err, delivery.ErrArchiveNameTaken) {
-			data := map[string]any{
-				tmplKeyWebhook: webhook,
-				tmplKeyError: "Not saved: " + err.Error() +
-					". Move that archive out of the data directory, " +
-					"its .db together with any -wal and -shm beside " +
+			h.renderWebhookEdit(
+				w, r, webhook, name, description, retention,
+				"Not saved: "+err.Error()+
+					". Move that archive out of the data directory, "+
+					"its .db together with any -wal and -shm beside "+
 					"it, then save again.",
-			}
-
-			h.renderTemplateStatus(w, r, "source_edit.html", data, http.StatusConflict)
+				http.StatusConflict,
+			)
 
 			return
 		}
@@ -797,6 +797,27 @@ func (h *Handlers) applyWebhookEdit(
 	)
 }
 
+// renderWebhookEdit renders the webhook edit page for the webhook as
+// stored, its form showing name, description and retentionDays, with
+// an optional error message above it.
+func (h *Handlers) renderWebhookEdit(
+	w http.ResponseWriter,
+	r *http.Request,
+	webhook *database.Webhook,
+	name, description, retentionDays, errMsg string,
+	status int,
+) {
+	data := map[string]any{
+		tmplKeyWebhook:  webhook,
+		tmplKeyError:    errMsg,
+		"Name":          name,
+		"Description":   description,
+		"RetentionDays": retentionDays,
+	}
+
+	h.renderTemplateStatus(w, r, "source_edit.html", data, status)
+}
+
 // HandleSourceDelete handles webhook deletion.
 func (h *Handlers) HandleSourceDelete() http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
@@ -1668,49 +1689,57 @@ func (h *Handlers) newTarget(
 	webhookID string,
 	in targetFormInput,
 ) (*database.Target, string, error) {
-	if in.Name == "" {
-		return nil, "Name is required", nil
+	target := &database.Target{
+		WebhookID: webhookID,
+		Type:      in.Type,
+		Active:    true,
 	}
 
-	if !isValidTargetType(in.Type) {
-		return nil, "Invalid target type", nil
-	}
-
-	configJSON, errMsg, err := h.buildTargetConfig(ctx, in.Type, in)
+	errMsg, err := h.setTargetFromForm(ctx, target, in)
 	if err != nil || errMsg != "" {
 		return nil, errMsg, err
 	}
 
-	// A new target has no stored retry count, so an absent field
-	// takes the fire-and-forget default. A field the operator filled
-	// in with something invalid is refused rather than becoming
-	// that default.
-	maxRetries, err := parseMaxRetries(in.MaxRetries, 0)
-	if err != nil {
-		return nil, "Invalid max retries: " + retriesErrorMessage(err), nil
-	}
-
-	return &database.Target{
-		WebhookID:  webhookID,
-		Name:       in.Name,
-		Type:       in.Type,
-		Active:     true,
-		Config:     configJSON,
-		MaxRetries: maxRetries,
-	}, "", nil
+	return target, "", nil
 }
 
-// isValidTargetType checks whether the target type is supported.
-func isValidTargetType(tt database.TargetType) bool {
-	switch tt {
-	case database.TargetTypeHTTP,
-		database.TargetTypeDatabase,
-		database.TargetTypeLog,
-		database.TargetTypeSlack:
-		return true
-	default:
-		return false
+// setTargetFromForm validates a target form against the target's type
+// and, when it accepts it, sets the target's name, configuration and
+// retry count from it. It returns the message the form shows for
+// anything it refuses, an unknown type among them, and then leaves the
+// target unchanged; an error is the server's fault, as for newTarget.
+// The add target form and the target edit form both go through here,
+// so the two cannot come to disagree about what a target may be.
+func (h *Handlers) setTargetFromForm(
+	ctx context.Context,
+	target *database.Target,
+	in targetFormInput,
+) (string, error) {
+	if in.Name == "" {
+		return "Name is required", nil
 	}
+
+	configJSON, errMsg, err := h.buildTargetConfig(ctx, target.Type, in)
+	if err != nil || errMsg != "" {
+		return errMsg, err
+	}
+
+	// An empty max_retries keeps the target's count: the
+	// fire-and-forget default of 0 for a new target, and the stored
+	// count for an edited one, since the forms for target types that
+	// do not retry have no such field. A value that is filled in but
+	// invalid is refused rather than becoming that count, so a typo
+	// cannot destroy the count a target is delivering with.
+	maxRetries, err := parseMaxRetries(in.MaxRetries, target.MaxRetries)
+	if err != nil {
+		return "Invalid max retries: " + retriesErrorMessage(err), nil
+	}
+
+	target.Name = in.Name
+	target.Config = configJSON
+	target.MaxRetries = maxRetries
+
+	return "", nil
 }
 
 // pageOrFirst parses a paginated page number, answering 1 for
@@ -1732,9 +1761,10 @@ func pageOrFirst(s string) int {
 }
 
 // targetFormInput carries the raw values of a target form. Both the
-// create and the edit path fill one and hand it to buildTargetConfig,
-// so neither can come to validate a destination differently from the
-// other. A refused add target form is shown again from it.
+// create and the edit path fill one and hand it to setTargetFromForm,
+// so neither can come to validate a target differently from the
+// other. Both forms are filled from one: the edit form with the
+// stored values, and a refused form with the values submitted.
 type targetFormInput struct {
 	// Name is the target's name.
 	Name string

internal/handlers/source_management_test.go

@@ -509,6 +509,51 @@ func TestHandleSourceEditSubmit_InvalidRetentionIsRejected(
 	)
 }
 
+// TestHandleSourceEditSubmit_RefusedFormComesBack refuses an edit for
+// each reason the form can give and checks that the form comes back
+// with the reason and the name, description and retention submitted,
+// that the page still reports the stored retention, and that nothing
+// is saved.
+func TestHandleSourceEditSubmit_RefusedFormComesBack(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	refused := func(name, retention, reason string) {
+		t.Helper()
+
+		wh := seedWebhookWithRetention(t, env.db, 30)
+
+		submitted := wh
+		submitted.Name = name
+		submitted.Description = "a description worth keeping"
+
+		w := submitEdit(t, env, submitted, retention)
+		assert.Equal(t, http.StatusBadRequest, w.Code)
+
+		page := w.Body.String()
+		assert.Contains(t, page, `class="alert-error">`+reason)
+		assert.Contains(t, page, `name="name" value="`+name+`"`)
+		assert.Contains(t, page, ">a description worth keeping</textarea>")
+		assert.Contains(
+			t, page, `name="retention_days" value="`+retention+`"`,
+		)
+		assert.Contains(t, page, "Currently 30 days.")
+
+		var stored database.Webhook
+
+		require.NoError(
+			t, env.db.DB().First(&stored, "id = ?", wh.ID).Error,
+		)
+		assert.Equal(t, wh.Name, stored.Name)
+		assert.Empty(t, stored.Description)
+		assert.Equal(t, 30, stored.RetentionDays)
+	}
+
+	refused("", "45", "Name is required")
+	refused("kept-name", "nonsense", "Retention must be")
+}
+
 func TestHandleSourceEditSubmit_EmptyRetentionLeavesValueUnchanged(
 	t *testing.T,
 ) {
@@ -809,6 +854,10 @@ func TestHandleSourceEditSubmit_ArchiveNameTaken(t *testing.T) {
 	w := submitEdit(t, env, wh, "")
 	require.Equal(t, http.StatusConflict, w.Code)
 	assert.Contains(t, w.Body.String(), "archive-taken.db")
+	assert.Contains(
+		t, w.Body.String(), `name="name" value="`+renamedWebhookName+`"`,
+		"the form comes back with the name submitted",
+	)
 
 	var stored database.Webhook
 

internal/handlers/target_edit.go

@@ -3,6 +3,7 @@ package handlers
 import (
 	"errors"
 	"net/http"
+	"strconv"
 
 	"github.com/go-chi/chi"
 	"sneak.berlin/go/webhooker/internal/database"
@@ -13,10 +14,13 @@ import (
 const targetEditTemplate = "target_edit.html"
 
 // tmplKeyTarget is the template data key for the target being
-// edited, and tmplKeyMaxTimeout for the timeout ceiling the form
-// tells the user about.
+// edited, tmplKeyTargetForm for the values its form shows, and
+// tmplKeyMaxTimeout for the timeout ceiling the form tells the user
+// about. The add target form on the webhook page takes its values
+// under the same key as the edit form.
 const (
 	tmplKeyTarget     = "Target"
+	tmplKeyTargetForm = "TargetForm"
 	tmplKeyMaxTimeout = "MaxTimeout"
 )
 
@@ -28,20 +32,19 @@ const configUnreadableMessage = "The stored configuration for this " +
 	"target could not be read. Enter the values below; saving " +
 	"replaces the stored configuration."
 
-// targetEditView is the display model for the target edit page.
+// targetEditView is the display model for the target edit page: the
+// target's row fields as stored. The values the form shows, the
+// UNMASKED configuration among them, come separately, as a
+// targetFormInput.
 //
-// It carries the target's row fields alongside its UNMASKED
-// configuration, and deliberately omits database.Target's raw
-// Config blob: the form renders named fields, and giving the
-// template the blob as well would put an unreviewed second path to
-// the credential on the page.
+// It deliberately omits database.Target's raw Config blob: the form
+// renders named fields, and giving the template the blob as well
+// would put an unreviewed second path to the credential on the page.
 type targetEditView struct {
-	ID         string
-	Name       string
-	Type       database.TargetType
-	Active     bool
-	MaxRetries int
-	Config     delivery.TargetConfigForm
+	ID     string
+	Name   string
+	Type   database.TargetType
+	Active bool
 }
 
 // HandleTargetEdit shows the form to edit a target.
@@ -73,7 +76,18 @@ func (h *Handlers) HandleTargetEdit() http.HandlerFunc {
 			msg = configUnreadableMessage
 		}
 
-		h.renderTargetEdit(w, r, webhook, target, cfg, msg)
+		form := targetFormInput{
+			Name:       target.Name,
+			URL:        cfg.URL,
+			Headers:    cfg.Headers,
+			Timeout:    cfg.Timeout,
+			MaxRetries: strconv.Itoa(target.MaxRetries),
+			Expiry:     cfg.Expiry,
+		}
+
+		h.renderTargetEdit(
+			w, r, webhook, target, form, msg, http.StatusOK,
+		)
 	}
 }
 
@@ -101,11 +115,12 @@ func (h *Handlers) HandleTargetEditSubmit() http.HandlerFunc {
 	}
 }
 
-// applyTargetEdit validates and saves target edits.
+// applyTargetEdit validates and saves target edits. A refused save
+// shows the edit form again with the values submitted and the reason.
 //
-// The submitted configuration goes through buildTargetConfig, the
-// same builder the create path uses, so an edited destination is
-// SSRF-validated exactly as a new one is.
+// The submission goes through setTargetFromForm, as a new target
+// does, so an edited destination is SSRF-validated exactly as a new
+// one is.
 //
 // The target's type is not editable. Each type stores a different
 // configuration shape and its delivery history is recorded against
@@ -118,16 +133,13 @@ func (h *Handlers) applyTargetEdit(
 	webhook database.Webhook,
 	target *database.Target,
 ) {
-	name := r.PostFormValue("name")
-	if name == "" {
-		http.Error(w, "Name is required", http.StatusBadRequest)
+	in := targetFormInputFrom(r)
 
-		return
-	}
+	// edited is the target as the submission leaves it; target stays
+	// as stored, for the page shown again when the save is refused.
+	edited := *target
 
-	configJSON, errMsg, err := h.buildTargetConfig(
-		r.Context(), target.Type, targetFormInputFrom(r),
-	)
+	errMsg, err := h.setTargetFromForm(r.Context(), &edited, in)
 	if err != nil {
 		h.serverError(w, r, "failed to encode target config", err)
 
@@ -135,45 +147,26 @@ func (h *Handlers) applyTargetEdit(
 	}
 
 	if errMsg != "" {
-		http.Error(w, errMsg, http.StatusBadRequest)
+		h.renderTargetEdit(
+			w, r, webhook, target, in, errMsg, http.StatusBadRequest,
+		)
 
 		return
 	}
 
-	// Retries are offered only by the forms for target types that
-	// retry, so an absent field means "this form does not edit
-	// retries" rather than "set them to zero". Reading it
-	// unconditionally would silently disable retries on any target
-	// saved from a form that does not render the input.
-	//
-	// A field that IS submitted but does not parse is a 400, through
-	// the same validator the create path uses. It is rejected before
-	// anything is written, so a typo cannot destroy the retry count
-	// the target is already delivering with.
-	if r.PostForm.Has("max_retries") {
-		retries, ok := targetMaxRetries(w, r, target.MaxRetries)
-		if !ok {
-			return
-		}
-
-		target.MaxRetries = retries
-	}
-
-	oldName := target.Name
-	target.Name = name
-	target.Config = configJSON
-
 	// A new name renames the archive file before it is saved (see
 	// delivery.Engine.Rename). If either step fails, it goes back to
 	// the name that is still stored.
-	err = h.renameTargetArchive(target, webhook.Name, oldName, name)
+	err = h.renameTargetArchive(
+		target, webhook.Name, target.Name, edited.Name,
+	)
 	if err == nil {
-		err = h.db.DB().Save(target).Error
+		err = h.db.DB().Save(&edited).Error
 	}
 
 	if err != nil {
 		restoreErr := h.renameTargetArchive(
-			target, webhook.Name, name, oldName,
+			target, webhook.Name, edited.Name, target.Name,
 		)
 		if restoreErr != nil {
 			h.log.Error(
@@ -184,8 +177,8 @@ func (h *Handlers) applyTargetEdit(
 		}
 
 		if errors.Is(err, delivery.ErrArchiveNameTaken) {
-			http.Error(
-				w,
+			h.renderTargetEdit(
+				w, r, webhook, target, in,
 				"Not saved: "+err.Error()+
 					". Move that archive out of the data directory, "+
 					"its .db together with any -wal and -shm beside "+
@@ -222,15 +215,17 @@ func (h *Handlers) renameTargetArchive(
 	return h.archives.Rename(target.ID, webhookName, newName)
 }
 
-// renderTargetEdit renders the target edit page with an optional
-// error message.
+// renderTargetEdit renders the target edit page for the target as
+// stored, its form showing form's values, with an optional error
+// message above it.
 func (h *Handlers) renderTargetEdit(
 	w http.ResponseWriter,
 	r *http.Request,
 	webhook database.Webhook,
 	target *database.Target,
-	cfg delivery.TargetConfigForm,
+	form targetFormInput,
 	errMsg string,
+	status int,
 ) {
 	// The template calls Webhook methods, which take pointer
 	// receivers; html/template cannot address a value stored in a
@@ -238,18 +233,17 @@ func (h *Handlers) renderTargetEdit(
 	data := map[string]any{
 		tmplKeyWebhook: &webhook,
 		tmplKeyTarget: targetEditView{
-			ID:         target.ID,
-			Name:       target.Name,
-			Type:       target.Type,
-			Active:     target.Active,
-			MaxRetries: target.MaxRetries,
-			Config:     cfg,
+			ID:     target.ID,
+			Name:   target.Name,
+			Type:   target.Type,
+			Active: target.Active,
 		},
+		tmplKeyTargetForm: form,
 		tmplKeyMaxTimeout: delivery.MaxTargetTimeoutSeconds,
 		tmplKeyError:      errMsg,
 	}
 
-	h.renderTemplate(w, r, targetEditTemplate, data)
+	h.renderTemplateStatus(w, r, targetEditTemplate, data, status)
 }
 
 // ownedTarget resolves the request's sourceID and targetID

internal/handlers/target_edit_test.go

@@ -565,6 +565,73 @@ func assertEditRejectsTimeout(
 	)
 }
 
+// TestHandleTargetEditSubmit_RefusedFormComesBack refuses an edit of
+// a target of each type and checks that the edit form comes back with
+// the reason and every value submitted, and that nothing is saved.
+func TestHandleTargetEditSubmit_RefusedFormComesBack(t *testing.T) {
+	t.Parallel()
+
+	env := setupSourceTest(t)
+
+	// fields is what the operator submitted, as a query string.
+	cases := []struct {
+		targetType database.TargetType
+		fields     string
+		reason     string
+	}{
+		{
+			database.TargetTypeHTTP,
+			"name=edited&url=" + editBlockedURL +
+				"&headers=X-Edited:+kept&timeout=12&max_retries=3",
+			"Invalid target URL",
+		},
+		{
+			database.TargetTypeSlack,
+			"name=edited&url=" + editOriginalURL + "&max_retries=25",
+			"Invalid max retries",
+		},
+		{
+			database.TargetTypeDatabase, "name=edited&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)
+			target := seedTarget(t, env.db, webhook.ID, tc.targetType)
+
+			form, err := url.ParseQuery(tc.fields)
+			require.NoError(t, err)
+
+			w := submitTargetEdit(env, webhook.ID, target.ID, form)
+			assert.Equal(t, http.StatusBadRequest, w.Code)
+
+			page := w.Body.String()
+			assert.Contains(t, page, `class="alert-error">`+tc.reason)
+
+			// headers is the form's one textarea; every other field is
+			// an input.
+			for field := range form {
+				shown := `name="` + field + `" value="` + form.Get(field) + `"`
+				if field == "headers" {
+					shown = ">" + form.Get(field) + "</textarea>"
+				}
+
+				assert.Contains(t, page, shown)
+			}
+
+			assert.Equal(
+				t, target.Name, storedTarget(t, env, target.ID).Name,
+				"a refused edit must save nothing",
+			)
+		})
+	}
+}
+
 // TestHandleTargetEdit_Scoping keeps the edit routes scoped the way
 // the delete and toggle routes are: ownership is decided by the
 // webhook, and the target is then scoped to it.
@@ -700,6 +767,10 @@ func TestHandleTargetEditSubmit_RenamesArchive(t *testing.T) {
 	w = submitTargetEdit(env, wh.ID, archive.ID, again)
 	require.Equal(t, http.StatusConflict, w.Code)
 	assert.Contains(t, w.Body.String(), "archive-taken.db")
+	assert.Contains(
+		t, w.Body.String(), `name="name" value="Again"`,
+		"the form comes back with the name submitted",
+	)
 	assert.Equal(
 		t, renamedTargetName, storedTarget(t, env, archive.ID).Name,
 	)

internal/handlers/target_private_refusal_test.go

@@ -44,9 +44,9 @@ func TestTargetRefusal_PrivateDestinationSaysHowToAllowIt(
 			form.Set("type", string(targetType))
 			form.Set("url", editBlockedURL)
 
-			// A refused add shows the webhook page again, where
-			// the hint is HTML-escaped; a refused edit answers in
-			// plain text.
+			// A refused add shows the webhook page again, and a
+			// refused edit the edit page, where the hint is
+			// HTML-escaped.
 			added := serveTarget(
 				env, http.MethodPost, targetsPath, form,
 			)
@@ -76,7 +76,8 @@ func TestTargetRefusal_PrivateDestinationSaysHowToAllowIt(
 			)
 			assert.Equal(t, http.StatusBadRequest, edited.Code)
 			assert.Contains(
-				t, edited.Body.String(), privateRefusalHint,
+				t, edited.Body.String(),
+				html.EscapeString(privateRefusalHint),
 			)
 		})
 	}

internal/handlers/target_retries.go

@@ -2,7 +2,6 @@ package handlers
 
 import (
 	"errors"
-	"net/http"
 	"strconv"
 	"strings"
 )
@@ -89,32 +88,3 @@ func retriesErrorMessage(err error) string {
 	return errRetriesInvalid.Error() +
 		", or 0 for fire-and-forget"
 }
-
-// targetMaxRetries reads and validates max_retries from a target edit
-// submission, answering the request with a 400 and reporting false
-// when the value is set but invalid.
-//
-// It and the create path (newTarget) both use parseMaxRetries and
-// retriesErrorMessage, so the two cannot come to disagree about what a
-// valid retry count is. The wording matches the timeout control on
-// the same submission.
-func targetMaxRetries(
-	w http.ResponseWriter,
-	r *http.Request,
-	fallback int,
-) (int, bool) {
-	retries, err := parseMaxRetries(
-		r.PostFormValue("max_retries"), fallback,
-	)
-	if err != nil {
-		http.Error(
-			w,
-			"Invalid max retries: "+retriesErrorMessage(err),
-			http.StatusBadRequest,
-		)
-
-		return 0, false
-	}
-
-	return retries, true
-}

internal/handlers/ui_copy_test.go

@@ -396,21 +396,21 @@ func TestTargetFormMaxRetriesCopyMatchesBehaviour(t *testing.T) {
 	)
 
 	// A slack target exercises the same max_retries field while needing
-	// only Config.URL from the edit template, so the test data stays
-	// minimal. The Target key mirrors the field names the template reads
-	// off the handler's view value.
+	// only a URL from the edit template, so the test data stays
+	// minimal. The Target and TargetForm keys mirror the field names
+	// the template reads off the handler's values.
 	editBody := renderPage(
 		t, h, sess, "target_edit.html", map[string]any{
 			dataKeyWebhook: webhook,
 			"Target": map[string]any{
-				"ID":         "tg-1",
-				"Name":       "t",
-				"Type":       "slack",
-				"Active":     true,
-				"MaxRetries": 3,
-				"Config": map[string]any{
-					"URL": "https://hooks.slack.com/services/x",
-				},
+				"ID":     "tg-1",
+				"Name":   "t",
+				"Type":   "slack",
+				"Active": true,
+			},
+			"TargetForm": map[string]any{
+				"URL":        "https://hooks.slack.com/services/x",
+				"MaxRetries": "3",
 			},
 			dataKeyError: "",
 		},

internal/server/alpine_browser_test.go

@@ -59,6 +59,44 @@ func TestAlpineRunsUnderTheSecurityPolicy(t *testing.T) {
 	t.Cleanup(srv.Close)
 
 	userID, _ := env.seedUser(t, "browser", "browser-password")
+	webhook, event, target := seedBrowserWebhook(t, env, userID)
+
+	require.NoError(t, chromedp.Run(
+		ctx, setCookies(srv.URL, env.authCookies(t, userID, "browser")),
+	))
+
+	page := srv.URL + "/hook/" + webhook.ID
+
+	// The checks share one browser tab, so they run one at a time, in
+	// this order. A new check is one more line here.
+	checkAddEntrypoint(ctx, t, page)
+	checkAddEachTargetType(ctx, t, page)
+	checkRefusedTarget(ctx, t, page)
+	checkTargetDeliveries(ctx, t, page, target.Name,
+		"0 in total, 0 in the last 24 hours",
+		"1 in total, 1 in the last 24 hours")
+	checkRefusedEdits(ctx, t, page, target.ID)
+	checkCopy(ctx, t, page)
+	checkEntrypointEdit(ctx, t, page, page+"/events")
+	checkRecentEvents(ctx, t, page)
+	checkEventLog(ctx, t, page+"/events", event.ID, target.Name)
+	checkArchiveChoice(ctx, t, srv.URL+"/hooks/new", page)
+	checkNewWebhookTargets(ctx, t, env, srv.URL+"/hooks/new")
+	checkRefusedNewWebhook(ctx, t, srv.URL+"/hooks/new")
+	checkMobileMenu(ctx, t, page)
+
+	assert.Empty(t, problems(), "the browser reported problems")
+}
+
+// seedBrowserWebhook seeds the webhook the browser test loads, owned by
+// userID: an entrypoint, two events, and a target whose delivery of the
+// newer event failed once with a 502. It returns the webhook, the newer
+// event and the target.
+func seedBrowserWebhook(
+	t *testing.T, env *testEnv, userID string,
+) (*database.Webhook, *database.Event, *database.Target) {
+	t.Helper()
+
 	webhook := env.seedWebhook(t, userID)
 	require.NoError(t, env.db.DB().Omit(clause.Associations).Create(
 		&database.Entrypoint{
@@ -82,56 +120,7 @@ func TestAlpineRunsUnderTheSecurityPolicy(t *testing.T) {
 		},
 	).Error)
 
-	require.NoError(t, chromedp.Run(
-		ctx, setCookies(srv.URL, env.authCookies(t, userID, "browser")),
-	))
-
-	page := srv.URL + "/hook/" + webhook.ID
-
-	checkAddEntrypoint(ctx, t, page)
-
-	// Each target type, with the fields its add target form submits, in
-	// page order. Only http and slack have a url field.
-	targetTypes := []struct {
-		name   string
-		fields string
-		values map[string]string
-	}{
-		{
-			"http", "csrf_token name type url headers timeout max_retries",
-			map[string]string{"url": publicTargetURL},
-		},
-		{
-			"slack", "csrf_token name type url max_retries",
-			map[string]string{"url": publicTargetURL},
-		},
-		{
-			"database", "csrf_token name type expiry",
-			map[string]string{"expiry": "720h"},
-		},
-		{"log", "csrf_token name type", nil},
-	}
-
-	for _, tt := range targetTypes {
-		checkAddTarget(
-			ctx, t, page, tt.name, strings.Fields(tt.fields), tt.values,
-		)
-	}
-
-	checkRefusedTarget(ctx, t, page)
-	checkTargetDeliveries(ctx, t, page, target.Name,
-		"0 in total, 0 in the last 24 hours",
-		"1 in total, 1 in the last 24 hours")
-	checkCopy(ctx, t, page)
-	checkEntrypointEdit(ctx, t, page, page+"/events")
-	checkRecentEvents(ctx, t, page)
-	checkEventLog(ctx, t, page+"/events", event.ID, target.Name)
-	checkArchiveChoice(ctx, t, srv.URL+"/hooks/new", page)
-	checkNewWebhookTargets(ctx, t, env, srv.URL+"/hooks/new")
-	checkRefusedNewWebhook(ctx, t, srv.URL+"/hooks/new")
-	checkMobileMenu(ctx, t, page)
-
-	assert.Empty(t, problems(), "the browser reported problems")
+	return webhook, event, target
 }
 
 // startBrowser starts a headless browser for one test. It returns the
@@ -310,6 +299,40 @@ const (
 		document.querySelector('form[action$="/targets"]')).keys()]`
 )
 
+// checkAddEachTargetType runs checkAddTarget on a webhook page for each
+// target type, in page order.
+func checkAddEachTargetType(ctx context.Context, t *testing.T, url string) {
+	t.Helper()
+
+	// Each target type, with the fields its add target form submits, in
+	// page order. Only http and slack have a url field.
+	targetTypes := []struct {
+		name   string
+		fields string
+		values map[string]string
+	}{
+		{
+			"http", "csrf_token name type url headers timeout max_retries",
+			map[string]string{"url": publicTargetURL},
+		},
+		{
+			"slack", "csrf_token name type url max_retries",
+			map[string]string{"url": publicTargetURL},
+		},
+		{
+			"database", "csrf_token name type expiry",
+			map[string]string{"expiry": "720h"},
+		},
+		{"log", "csrf_token name type", nil},
+	}
+
+	for _, tt := range targetTypes {
+		checkAddTarget(
+			ctx, t, url, tt.name, strings.Fields(tt.fields), tt.values,
+		)
+	}
+}
+
 // checkAddTarget loads a webhook page and walks the add target form for
 // one target type. The form shows nothing until Add is clicked; Add
 // shows only the type choice; Cancel there closes it; Next shows the
@@ -481,6 +504,64 @@ func checkTargetDeliveries(
 		"the row of %s does not show %q failed", name, failed)
 }
 
+// checkRefusedEdits fills in the target edit page and the webhook edit
+// page of a webhook page with values the server refuses, a loopback
+// destination and a retention above the longest finite one, which the
+// browser lets through. It saves each and checks that the page comes
+// back with the reason and every value still in its field. The values
+// are keyed by the id of their field.
+func checkRefusedEdits(
+	ctx context.Context, t *testing.T, page, targetID string,
+) {
+	t.Helper()
+
+	const reason = `//div[@class="alert-error"]`
+
+	edits := []struct {
+		url    string
+		values map[string]string
+	}{
+		{page + "/targets/" + targetID + "/edit", map[string]string{
+			"#name":        "edited-target",
+			"#url":         "http://127.0.0.1/hook",
+			"#headers":     "X-Edited: kept",
+			"#timeout":     "12",
+			"#max_retries": "3",
+		}},
+		{page + "/edit", map[string]string{
+			"#name":           "edited-webhook",
+			"#description":    "kept description",
+			"#retention_days": "200000",
+		}},
+	}
+
+	for _, edit := range edits {
+		require.NoError(t, chromedp.Run(ctx, loadPage(edit.url)))
+
+		for field, value := range edit.values {
+			require.NoError(t, chromedp.Run(
+				ctx, chromedp.SetValue(field, value, chromedp.ByQuery),
+			))
+		}
+
+		click(ctx, t, `//button[text()="Save Changes"]`)
+
+		assert.Truef(t, shown(ctx, reason),
+			"%s: a refused save does not show the reason", edit.url)
+
+		for field, value := range edit.values {
+			var kept string
+
+			require.NoError(t, chromedp.Run(
+				ctx, chromedp.Value(field, &kept, chromedp.ByQuery),
+			))
+			assert.Equalf(t, value, kept,
+				"%s: a refused save does not keep the %s entered",
+				edit.url, field)
+		}
+	}
+}
+
 // checkCopy loads a webhook page and checks that the Copy control beside
 // its entrypoint's URL is a button, and that clicking it copies the URL
 // and says so: the button reads "Copied" only once the copy succeeded.