Load Alpine's CSP build so the UI's directives run (closes #371)

The pages' Content-Security-Policy forbids eval, which the standard
Alpine.js build needs, so no directive ran: add forms showed open and
events never collapsed. 3p/ now holds the @alpinejs/csp 3.14.9 tarball
instead, and every directive in templates/ names a property or method
of a component registered in static/js/app.js, as that build requires.
The policy is unchanged.

A headless Chromium test in internal/server loads the webhook page and
the event log under the real headers. The Dockerfile's test stage
installs chromium; where it is missing the test skips.

Model: opus-5-5

Dockerfile

@@ -38,8 +38,9 @@ FROM golang:1.26.1-bookworm@sha256:4465644228bc2857a954b092167e12aa59c006a349228
 COPY --from=lint /src/go.sum /dev/null
 
 # jq is a runtime dependency of script/ci-mark-superseded, which the test
-# suite executes.
+# suite executes. chromium runs the browser test in internal/server, which
-RUN apt-get update && apt-get install -y --no-install-recommends make curl ca-certificates jq && rm -rf /var/lib/apt/lists/*
+# skips where it is not installed.
+RUN apt-get update && apt-get install -y --no-install-recommends make curl ca-certificates jq chromium && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /build
 

README.md

@@ -1270,9 +1270,20 @@ We provide:
 
 ## Third-party browser assets
 
-The web UI serves one third-party script, Alpine.js. Its npm package tarball
+The web UI serves one third-party script, Alpine.js, in its CSP build: the npm
-is committed as `3p/alpinejs-3.14.9.tgz`, byte for byte as the npm registry
+package `@alpinejs/csp`. The pages' Content-Security-Policy forbids eval, which
-publishes it. It is a dependency, not this repo's build output, so
+the standard `alpinejs` build needs to run the expressions written in the
+markup. The CSP build runs no expressions, so every Alpine directive in
+`templates/` only names a property or method of a component registered in
+`static/js/app.js`: `x-data="collapsible"` and `@click="toggle"`, never
+`x-data="{ open: false }"` or `@click="open = !open"`. A browser test in
+`internal/server` loads the pages under the real policy and fails on any
+directive that does not work. It needs `chromium` on `PATH` and skips without
+it; the Dockerfile installs it, so the image build always runs it.
+
+The package's tarball is committed as `3p/alpinejs-csp-3.14.9.tgz`, byte for
+byte as the npm registry publishes it. It is a dependency, not this repo's
+build output, so
 `REPO_POLICIES.md`'s rule against committed build artifacts does not apply.
 The directory is `3p/` rather than `vendor/` because Go treats a root
 `vendor/` directory as its module vendor directory.
@@ -1285,10 +1296,11 @@ nothing downloads Alpine.js. The extracted file is not committed, and
 `.dockerignore` keeps any host copy out of the build context.
 
 To move to a new version: download
-`https://registry.npmjs.org/alpinejs/-/alpinejs-<version>.tgz`, check it
+`https://registry.npmjs.org/@alpinejs/csp/-/csp-<version>.tgz`, check it
 against the `dist.integrity` hash listed at
-`https://registry.npmjs.org/alpinejs/<version>`, replace the tarball in `3p/`
+`https://registry.npmjs.org/@alpinejs/csp/<version>`, replace the tarball in
-with it, update its file name in `script/assets`, and run `make check`.
+`3p/` with it as `alpinejs-csp-<version>.tgz`, update its file name in
+`script/assets`, and run `make check`.
 
 ## Rationale
 
@@ -2769,7 +2781,7 @@ imports. The entry point is `cmd/webhooker/main.go`.
 ```
 webhooker/
 ├── 3p/
-│   └── alpinejs-3.14.9.tgz    # Alpine.js npm package, extracted by make assets
+│   └── alpinejs-csp-3.14.9.tgz  # Alpine.js CSP build npm package, extracted by make assets
 ├── cmd/webhooker/
 │   └── main.go               # Entry point: subcommand dispatch; no args locks DATA_DIR and wires fx
 ├── internal/
@@ -2862,8 +2874,8 @@ webhooker/
 │   ├── css/input.css          # Tailwind input, source for tailwind.css (make css)
 │   ├── css/tailwind.css       # Generated stylesheet the pages load
 │   ├── css/style.css          # Older hand-written stylesheet, no longer loaded
-│   ├── js/app.js              # Progressive-enhancement copy-to-clipboard
+│   ├── js/app.js              # Copy-to-clipboard, and the Alpine.js components
-│   └── js/alpine.min.js       # Alpine.js, extracted from 3p/ by make assets, not committed
+│   └── js/alpine.min.js       # Alpine.js CSP build, extracted from 3p/ by make assets, not committed
 ├── templates/                 # Go HTML templates (base, login, sources, etc.)
 ├── script/                    # Scripts to Rule Them All entrypoints
 ├── Dockerfile                 # Three stages: lint, test+build, Alpine runtime

go.mod

@@ -4,6 +4,8 @@ go 1.26.1
 
 require (
 	github.com/99designs/basicauth-go v0.0.0-20230316000542-bf6f9cbbf0f8
+	github.com/chromedp/cdproto v0.0.0-20260922220944-a19bff23514f
+	github.com/chromedp/chromedp v0.16.0
 	github.com/dustin/go-humanize v1.0.1
 	github.com/getsentry/sentry-go v0.25.0
 	github.com/go-chi/chi v1.5.5
@@ -29,7 +31,12 @@ require (
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/chromedp/sysutil v1.1.0 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
+	github.com/go-json-experiment/json v0.0.0-20260820222146-c27c302e5fc3 // indirect
+	github.com/gobwas/httphead v0.1.0 // indirect
+	github.com/gobwas/pool v0.2.1 // indirect
+	github.com/gobwas/ws v1.4.0 // indirect
 	github.com/gorilla/securecookie v1.1.2 // indirect
 	github.com/jinzhu/inflection v1.0.0 // indirect
 	github.com/jinzhu/now v1.1.5 // indirect
@@ -50,7 +57,7 @@ require (
 	go.uber.org/zap v1.23.0 // indirect
 	golang.org/x/mod v0.17.0 // indirect
 	golang.org/x/sync v0.14.0 // indirect
-	golang.org/x/sys v0.37.0 // indirect
+	golang.org/x/sys v0.47.0 // indirect
 	golang.org/x/text v0.25.0 // indirect
 	golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d // indirect
 	google.golang.org/protobuf v1.31.0 // indirect

go.sum

@@ -6,6 +6,12 @@ github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
 github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/chromedp/cdproto v0.0.0-20260922220944-a19bff23514f h1:8PK9FM4bE0C8GMoWBW5lVsef3U7sPICjDg6JqngyYhk=
+github.com/chromedp/cdproto v0.0.0-20260922220944-a19bff23514f/go.mod h1:3v4FIp5njIUyPDvqXsxEOxnB34lijG0up98/5kM1KaE=
+github.com/chromedp/chromedp v0.16.0 h1:rOO4deOm4CbZgBCa8mD9g2rDyIoNs0BkgvNrlbp5ouk=
+github.com/chromedp/chromedp v0.16.0/go.mod h1:rbuGKFT1vMcFcFqKfPIO1GpX/N+2s8onm2qMxZLbU5U=
+github.com/chromedp/sysutil v1.1.0 h1:PUFNv5EcprjqXZD9nJb9b/c9ibAbxiYo4exNWZyipwM=
+github.com/chromedp/sysutil v1.1.0/go.mod h1:WiThHUdltqCNKGc4gaU50XgYjwjYIhKWoHGPTUfWTJ8=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -23,6 +29,14 @@ github.com/go-chi/httprate v0.15.0 h1:j54xcWV9KGmPf/X4H32/aTH+wBlrvxL7P+SdnRqxh5
 github.com/go-chi/httprate v0.15.0/go.mod h1:rzGHhVrsBn3IMLYDOZQsSU4fJNWcjui4fWKJcCId1R4=
 github.com/go-errors/errors v1.4.2 h1:J6MZopCL4uSllY1OfXM374weqZFFItUbrImctkmUxIA=
 github.com/go-errors/errors v1.4.2/go.mod h1:sIVyrIiJhuEF+Pj9Ebtd6P/rEYROXFi3BopGUQ5a5Og=
+github.com/go-json-experiment/json v0.0.0-20260820222146-c27c302e5fc3 h1:UADEEmDKgfXbtnGJZ97beY5XLo9ZechG1nlU4KnRrkE=
+github.com/go-json-experiment/json v0.0.0-20260820222146-c27c302e5fc3/go.mod h1:tphK2c80bpPhMOI4v6bIc2xWywPfbqi1Z06+RcrMkDg=
+github.com/gobwas/httphead v0.1.0 h1:exrUm0f4YX0L7EBwZHuCF4GDp8aJfVeBrlLQrs6NqWU=
+github.com/gobwas/httphead v0.1.0/go.mod h1:O/RXo79gxV8G+RqlR/otEwx4Q36zl9rqC5u12GKvMCM=
+github.com/gobwas/pool v0.2.1 h1:xfeeEhW7pwmX8nuLVlqbzVc7udMDrwetjEv+TZIz1og=
+github.com/gobwas/pool v0.2.1/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
+github.com/gobwas/ws v1.4.0 h1:CTaoG1tojrh4ucGPcoJFiAQUAsEWekEWvLy7GsVNqGs=
+github.com/gobwas/ws v1.4.0/go.mod h1:G3gNqMNtPppf5XUz7O4shetPpcZ1VJ7zt18dlUeakrc=
 github.com/gofrs/flock v0.13.0 h1:95JolYOvGMqeH31+FC7D2+uULf6mG61mEZ/A8dRYMzw=
 github.com/gofrs/flock v0.13.0/go.mod h1:jxeyy9R1auM5S6JYDBhDt+E2TCo7DkratH4Pgi8P+Z0=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
@@ -55,12 +69,16 @@ github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/ledongthuc/pdf v0.0.0-20220302134840-0c2507a12d80 h1:6Yzfa6GP0rIo/kULo2bwGEkFvCePZ3qHDDTC3/J9Swo=
+github.com/ledongthuc/pdf v0.0.0-20220302134840-0c2507a12d80/go.mod h1:imJHygn/1yfhB7XSJJKlFZKl/J+dCPAknuiaGOshXAs=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-sqlite3 v1.14.17 h1:mCRHCLDUBXgpKAqIKsaAaAsrAlbkeomtRFKXh2L6YIM=
 github.com/mattn/go-sqlite3 v1.14.17/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=
 github.com/matttproud/golang_protobuf_extensions/v2 v2.0.0 h1:jWpvCLoY8Z/e3VKvlsiIGKtc+UG6U5vzxaoagmhXfyg=
 github.com/matttproud/golang_protobuf_extensions/v2 v2.0.0/go.mod h1:QUyp042oQthUoa9bqDv0ER0wrtXnBruoNd7aNjkbP+k=
+github.com/orisano/pixelmatch v0.0.0-20220722002657-fb0b55479cde h1:x0TT0RDC7UhAVbbWWBzr41ElhJx5tXPWkIHA2HWPRuw=
+github.com/orisano/pixelmatch v0.0.0-20220722002657-fb0b55479cde/go.mod h1:nZgzbfBr3hhjoZnS66nKrHmduYNpc34ny7RK4z5/HM0=
 github.com/pingcap/errors v0.11.4 h1:lFuQV/oaUMGcD2tqt+01ROSmJs75VG1ToEOkZIZ4nE4=
 github.com/pingcap/errors v0.11.4/go.mod h1:Oi8TUi2kEtXXLMJk9l1cGmz20kV3TaQ0usTwv5KuLY8=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
@@ -111,8 +129,8 @@ golang.org/x/mod v0.17.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/sync v0.14.0 h1:woo0S4Yywslg6hp4eUFjTVOyKt0RookbpAHG4c1HmhQ=
 golang.org/x/sync v0.14.0/go.mod h1:1dzgHSNfp02xaA81J2MS99Qcpr2w7fw1gpm99rleRqA=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.37.0 h1:fdNQudmxPjkdUTPnLn5mdQv7Zwvbvpaxqs831goi9kQ=
+golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
-golang.org/x/sys v0.37.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/sys v0.47.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/text v0.25.0 h1:qVyWApTSYLk/drJRO5mDlNYskwQznZmkpV2c8q9zls4=
 golang.org/x/text v0.25.0/go.mod h1:WEdwpYrmk1qmdHvhkSTNPm3app7v4rsT8F2UD6+VHIA=
 golang.org/x/tools v0.21.1-0.20240508182429-e35e4ccd0d2d h1:vU5i/LfpvrRCpgM/VPfJLg5KjxD3E+hfT1SH+d9zLwg=

internal/server/alpine_browser_test.go

@@ -0,0 +1,276 @@
+package server_test
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"os/exec"
+	"slices"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/chromedp/cdproto/network"
+	"github.com/chromedp/cdproto/runtime"
+	"github.com/chromedp/chromedp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+const (
+	// browserTimeout bounds everything one test does in the browser.
+	browserTimeout = 60 * time.Second
+
+	// settleTimeout bounds the wait for an element to show or hide.
+	settleTimeout = 5 * time.Second
+)
+
+// TestAlpineRunsUnderTheSecurityPolicy loads the webhook page and the
+// event log in headless Chromium, served by the real router and so
+// under the real Content-Security-Policy, and checks that the pages'
+// Alpine.js directives work.
+func TestAlpineRunsUnderTheSecurityPolicy(t *testing.T) {
+	t.Parallel()
+
+	ctx, consoleProblems := startBrowser(t)
+
+	env := newTestEnv(t)
+	srv := httptest.NewServer(env.router)
+	t.Cleanup(srv.Close)
+
+	userID, _ := env.seedUser(t, "browser", "browser-password")
+	webhook := env.seedWebhook(t, userID)
+	event := env.seedEvent(t, webhook.ID, `{"hello":"browser"}`)
+
+	require.NoError(t, chromedp.Run(
+		ctx, setCookies(srv.URL, env.authCookies(t, userID, "browser")),
+	))
+
+	checkAddForms(ctx, t, srv.URL+"/source/"+webhook.ID)
+	checkTargetType(ctx, t)
+	checkEventToggle(
+		ctx, t, srv.URL+"/source/"+webhook.ID+"/logs", event.ID,
+	)
+
+	assert.Empty(
+		t, consoleProblems(),
+		"the pages printed console warnings, errors or exceptions",
+	)
+}
+
+// startBrowser starts headless Chromium for one test. It returns the
+// context that drives it, and a function listing every console warning
+// or error and every uncaught exception its pages raised: that is how
+// Alpine.js reports an expression it cannot run.
+//
+// The test is skipped when chromium is not on PATH. The Dockerfile's
+// test stage installs it, so the image build always runs this check.
+func startBrowser(t *testing.T) (context.Context, func() []string) {
+	t.Helper()
+
+	path, err := exec.LookPath("chromium")
+	if err != nil {
+		t.Skipf("chromium is not installed: %v", err)
+	}
+
+	allocCtx, cancelAlloc := chromedp.NewExecAllocator(
+		t.Context(),
+		append(
+			chromedp.DefaultExecAllocatorOptions[:],
+			chromedp.ExecPath(path),
+			// The image build runs tests as root, where Chromium's
+			// sandbox cannot start.
+			chromedp.NoSandbox,
+		)...,
+	)
+	t.Cleanup(cancelAlloc)
+
+	ctx, cancel := chromedp.NewContext(allocCtx)
+	t.Cleanup(cancel)
+
+	ctx, cancelTimeout := context.WithTimeout(ctx, browserTimeout)
+	t.Cleanup(cancelTimeout)
+
+	var (
+		mu       sync.Mutex
+		problems []string
+	)
+
+	chromedp.ListenTarget(ctx, func(ev any) {
+		var problem string
+
+		switch ev := ev.(type) {
+		case *runtime.EventConsoleAPICalled:
+			if ev.Type != runtime.APITypeWarning &&
+				ev.Type != runtime.APITypeError {
+				return
+			}
+
+			args := make([]string, 0, len(ev.Args))
+			for _, arg := range ev.Args {
+				args = append(args, string(arg.Value))
+			}
+
+			problem = strings.Join(args, " ")
+		case *runtime.EventExceptionThrown:
+			problem = ev.ExceptionDetails.Error()
+		default:
+			return
+		}
+
+		mu.Lock()
+		defer mu.Unlock()
+
+		problems = append(problems, problem)
+	})
+
+	return ctx, func() []string {
+		mu.Lock()
+		defer mu.Unlock()
+
+		return slices.Clone(problems)
+	}
+}
+
+// setCookies gives the browser the cookies for the server at base.
+func setCookies(base string, cookies []*http.Cookie) chromedp.ActionFunc {
+	return chromedp.ActionFunc(func(ctx context.Context) error {
+		for _, c := range cookies {
+			err := network.SetCookie(c.Name, c.Value).
+				WithURL(base).
+				Do(ctx)
+			if err != nil {
+				return fmt.Errorf("set cookie %s: %w", c.Name, err)
+			}
+		}
+
+		return nil
+	})
+}
+
+// loadPage opens url and waits for Alpine.js to start, which it does
+// by removing every x-cloak attribute. Until then x-cloak hides the
+// elements Alpine would hide, so a check made earlier proves nothing.
+func loadPage(url string) chromedp.Tasks {
+	return chromedp.Tasks{
+		chromedp.Navigate(url),
+		chromedp.WaitNotPresent("[x-cloak]", chromedp.ByQuery),
+	}
+}
+
+// shown waits up to settleTimeout for the first element matching a CSS
+// selector to be rendered, and reports whether it was. The wait is
+// needed because Alpine.js shows an element on the next animation
+// frame, not at once.
+func shown(ctx context.Context, selector string) bool {
+	ctx, cancel := context.WithTimeout(ctx, settleTimeout)
+	defer cancel()
+
+	return chromedp.Run(
+		ctx, chromedp.WaitVisible(selector, chromedp.ByQuery),
+	) == nil
+}
+
+// hidden is shown's opposite: it waits for the element to be hidden.
+func hidden(ctx context.Context, selector string) bool {
+	ctx, cancel := context.WithTimeout(ctx, settleTimeout)
+	defer cancel()
+
+	return chromedp.Run(
+		ctx, chromedp.WaitNotVisible(selector, chromedp.ByQuery),
+	) == nil
+}
+
+// click clicks the first element matching an XPath expression.
+func click(ctx context.Context, t *testing.T, xpath string) {
+	t.Helper()
+
+	require.NoError(t, chromedp.Run(
+		ctx, chromedp.Click(xpath, chromedp.BySearch),
+	))
+}
+
+// checkAddForms loads a webhook page and checks that each section's add
+// form stays hidden until the Add button beside its heading is clicked.
+func checkAddForms(ctx context.Context, t *testing.T, url string) {
+	t.Helper()
+
+	require.NoError(t, chromedp.Run(ctx, loadPage(url)))
+
+	sections := []struct{ heading, form string }{
+		{"Entrypoints", `form[action$="/entrypoints"]`},
+		{"Targets", `form[action$="/targets"]`},
+	}
+
+	for _, s := range sections {
+		assert.Truef(
+			t, hidden(ctx, s.form),
+			"%s: the add form shows before Add is clicked", s.heading,
+		)
+
+		click(ctx, t, `//h2[text()="`+s.heading+
+			`"]/following-sibling::button`)
+
+		assert.Truef(
+			t, shown(ctx, s.form),
+			"%s: the add form stays hidden when Add is clicked", s.heading,
+		)
+	}
+}
+
+// checkTargetType chooses Slack in the open add target form and checks
+// what the form would then submit: one url field, the Slack one, and
+// not the HTTP url, headers or timeout, which are hidden and disabled.
+func checkTargetType(ctx context.Context, t *testing.T) {
+	t.Helper()
+
+	const (
+		chooseSlack = `(() => {
+			const type = document.querySelector('select[name="type"]');
+			type.value = "slack";
+			type.dispatchEvent(new Event("change"));
+		})()`
+		submitted = `[...new FormData(
+			document.querySelector('form[action$="/targets"]')).keys()]`
+	)
+
+	var fields []string
+
+	require.NoError(t, chromedp.Run(
+		ctx,
+		chromedp.Evaluate(chooseSlack, nil),
+		chromedp.Evaluate(submitted, &fields),
+	))
+
+	assert.Equal(
+		t,
+		[]string{"csrf_token", "name", "type", "max_retries", "url"},
+		fields,
+		"with Slack chosen, the HTTP fields must not be submitted",
+	)
+}
+
+// checkEventToggle loads the event log and checks that clicking an
+// event's row expands it and clicking again collapses it.
+func checkEventToggle(
+	ctx context.Context, t *testing.T, url, eventID string,
+) {
+	t.Helper()
+
+	// The row shows the event's ID; its Resubmit form is in the part
+	// that expands.
+	row := `//span[text()="` + eventID + `"]`
+	expanded := `form[action$="/resubmit"]`
+
+	require.NoError(t, chromedp.Run(ctx, loadPage(url)))
+
+	assert.True(t, hidden(ctx, expanded), "the event starts expanded")
+
+	click(ctx, t, row)
+	assert.True(t, shown(ctx, expanded), "clicking the event does not expand it")
+
+	click(ctx, t, row)
+	assert.True(t, hidden(ctx, expanded), "clicking it again does not collapse it")
+}

script/assets

@@ -1,15 +1,16 @@
 #!/bin/sh
 # script/assets: extract Alpine.js from its npm package tarball, committed
-# in 3p/, to static/js/alpine.min.js, where go:embed reads it. The
+# in 3p/, to static/js/alpine.min.js, where go:embed reads it. The package
-# extracted file is not committed. script/test, make build and make dev run
+# is @alpinejs/csp, Alpine's build for pages whose Content-Security-Policy
-# this first.
+# forbids eval. The extracted file is not committed. script/test, make
+# build and make dev run this first.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    tar -xzOf 3p/alpinejs-3.14.9.tgz package/dist/cdn.min.js \
+    tar -xzOf 3p/alpinejs-csp-3.14.9.tgz package/dist/cdn.min.js \
         >static/js/alpine.min.js
 }
 

static/js/app.js

@@ -57,3 +57,62 @@
         init();
     }
 })();
+
+// Alpine.js components.
+//
+// The pages' Content-Security-Policy forbids eval, so the UI loads
+// Alpine's CSP build, which cannot run expressions written in the
+// markup: a directive in templates/ may only name a property or method,
+// and each x-data names a component registered here. This script runs
+// before Alpine, whose script tag is deferred, so this listener is in
+// place when Alpine starts.
+document.addEventListener("alpine:init", function () {
+    "use strict";
+
+    // Something a click shows and hides: the mobile menu, an add form,
+    // an event in the event log, a delivery's attempts.
+    window.Alpine.data("collapsible", function () {
+        return {
+            open: false,
+            toggle() {
+                this.open = !this.open;
+            },
+            get closed() {
+                return !this.open;
+            },
+            // Turns a downward caret up while open.
+            get caretClass() {
+                return { "rotate-180": this.open };
+            },
+        };
+    });
+
+    // The add target form. Only the chosen type's fields show, and the
+    // others are disabled so that the form does not submit them.
+    window.Alpine.data("targetForm", function () {
+        return {
+            targetType: "http",
+            chooseType(event) {
+                this.targetType = event.target.value;
+            },
+            get isHttp() {
+                return this.targetType === "http";
+            },
+            get isSlack() {
+                return this.targetType === "slack";
+            },
+            get isDatabase() {
+                return this.targetType === "database";
+            },
+            get notHttp() {
+                return !this.isHttp;
+            },
+            get notSlack() {
+                return !this.isSlack;
+            },
+            get notDatabase() {
+                return !this.isDatabase;
+            },
+        };
+    });
+});

templates/navbar.html

@@ -1,14 +1,14 @@
 {{define "navbar"}}
-<nav class="app-bar" x-data="{ open: false }">
+<nav class="app-bar" x-data="collapsible">
     <div class="max-w-6xl mx-auto flex justify-between items-center">
         <div class="flex items-center gap-3">
             <a href="/" class="text-xl font-medium text-gray-900 hover:text-primary-600 transition-colors">Webhooker</a>
         </div>
 
         <!-- Mobile menu button -->
-        <button @click="open = !open" class="md:hidden p-2 rounded-md text-gray-500 hover:bg-gray-100">
+        <button @click="toggle" class="md:hidden p-2 rounded-md text-gray-500 hover:bg-gray-100">
             <svg class="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-                <path x-show="!open" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 6h16M4 12h16M4 18h16"/>
+                <path x-show="closed" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M4 6h16M4 12h16M4 18h16"/>
                 <path x-show="open" x-cloak stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12"/>
             </svg>
         </button>

templates/source_detail.html

@@ -3,7 +3,7 @@
 {{define "title"}}{{.Webhook.Name}} - Webhooker{{end}}
 
 {{define "content"}}
-<div class="max-w-6xl mx-auto px-6 py-8" x-data="{ showAddEntrypoint: false, showAddTarget: false }">
+<div class="max-w-6xl mx-auto px-6 py-8">
     <div class="mb-6">
         <a href="/sources" class="text-sm text-primary-600 hover:text-primary-700">&larr; Back to webhooks</a>
         <div class="flex justify-between items-center mt-2">
@@ -26,10 +26,10 @@
 
     <div class="grid grid-cols-1 lg:grid-cols-2 gap-6">
         <!-- Entrypoints -->
-        <div class="card">
+        <div class="card" x-data="collapsible">
             <div class="p-4 border-b border-gray-200 flex justify-between items-center">
                 <h2 class="text-lg font-medium text-gray-900">Entrypoints</h2>
-                <button @click="showAddEntrypoint = !showAddEntrypoint" class="btn-text text-sm">
+                <button @click="toggle" class="btn-text text-sm">
                     <svg class="w-4 h-4 mr-1" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                         <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 4v16m8-8H4"/>
                     </svg>
@@ -38,7 +38,7 @@
             </div>
 
             <!-- Add entrypoint form -->
-            <div x-show="showAddEntrypoint" x-cloak class="p-4 bg-gray-50 border-b border-gray-200">
+            <div x-show="open" x-cloak class="p-4 bg-gray-50 border-b border-gray-200">
                 <form method="POST" action="/source/{{.Webhook.ID}}/entrypoints" class="flex gap-2">
                     <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
                     <input type="text" name="description" placeholder="Description (optional)" class="input text-sm flex-1">
@@ -85,10 +85,10 @@
         </div>
 
         <!-- Targets -->
-        <div class="card">
+        <div class="card" x-data="collapsible">
             <div class="p-4 border-b border-gray-200 flex justify-between items-center">
                 <h2 class="text-lg font-medium text-gray-900">Targets</h2>
-                <button @click="showAddTarget = !showAddTarget" class="btn-text text-sm">
+                <button @click="toggle" class="btn-text text-sm">
                     <svg class="w-4 h-4 mr-1" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                         <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 4v16m8-8H4"/>
                     </svg>
@@ -97,42 +97,42 @@
             </div>
 
             <!-- Add target form -->
-            <div x-show="showAddTarget" x-cloak class="p-4 bg-gray-50 border-b border-gray-200">
+            <div x-show="open" x-cloak class="p-4 bg-gray-50 border-b border-gray-200">
-                <form method="POST" action="/source/{{.Webhook.ID}}/targets" x-data="{ targetType: 'http' }" class="space-y-3">
+                <form method="POST" action="/source/{{.Webhook.ID}}/targets" x-data="targetForm" class="space-y-3">
                     <input type="hidden" name="csrf_token" value="{{.CSRFToken}}">
                     <div class="flex gap-2">
                         <input type="text" name="name" placeholder="Target name" required class="input text-sm flex-1">
-                        <select name="type" x-model="targetType" class="input text-sm w-32">
+                        <select name="type" @change="chooseType" class="input text-sm w-32">
                             <option value="http">HTTP</option>
                             <option value="slack">Slack</option>
                             <option value="database">Database</option>
                             <option value="log">Log</option>
                         </select>
                     </div>
-                    <div x-show="targetType === 'http'">
+                    <div x-show="isHttp">
-                        <input type="url" name="url" placeholder="https://example.com/webhook" :disabled="targetType !== 'http'" class="input text-sm">
+                        <input type="url" name="url" placeholder="https://example.com/webhook" :disabled="notHttp" class="input text-sm">
                     </div>
-                    <div x-show="targetType === 'http'">
+                    <div x-show="isHttp">
-                        <textarea name="headers" rows="3" placeholder="Authorization: Bearer ..." :disabled="targetType !== 'http'" class="input text-sm"></textarea>
+                        <textarea name="headers" rows="3" placeholder="Authorization: Bearer ..." :disabled="notHttp" class="input text-sm"></textarea>
                         <p class="text-xs text-gray-500 mt-1">Optional request headers, one <code>Name: value</code> per line, sent with every delivery.</p>
                     </div>
-                    <div x-show="targetType === 'http'" class="flex gap-2 items-center">
+                    <div x-show="isHttp" class="flex gap-2 items-center">
                         <label class="text-sm text-gray-700">Timeout (seconds, blank = default):</label>
-                        <input type="number" name="timeout" min="0" max="300" :disabled="targetType !== 'http'" class="input text-sm w-24">
+                        <input type="number" name="timeout" min="0" max="300" :disabled="notHttp" class="input text-sm w-24">
                     </div>
-                    <div x-show="targetType === 'http'">
+                    <div x-show="isHttp">
                         <div class="flex gap-2 items-center">
                             <label class="text-sm text-gray-700">Max retries:</label>
                             <input type="number" name="max_retries" value="0" min="0" max="20" class="input text-sm w-24">
                         </div>
                         <p class="text-xs text-gray-500 mt-1">This is the total number of delivery attempts, not retries on top of the first: a value of 3 makes three attempts in all. 0 means a single attempt with no retries and no circuit breaker.</p>
                     </div>
-                    <div x-show="targetType === 'slack'">
+                    <div x-show="isSlack">
-                        <input type="url" name="url" placeholder="https://hooks.slack.com/services/..." :disabled="targetType !== 'slack'" class="input text-sm">
+                        <input type="url" name="url" placeholder="https://hooks.slack.com/services/..." :disabled="notSlack" class="input text-sm">
                         <p class="text-xs text-gray-500 mt-1">Slack or Mattermost incoming webhook URL. Payloads are pretty-printed in code blocks.</p>
                     </div>
-                    <div x-show="targetType === 'database'">
+                    <div x-show="isDatabase">
-                        <input type="text" name="expiry" placeholder="never" :disabled="targetType !== 'database'" class="input text-sm">
+                        <input type="text" name="expiry" placeholder="never" :disabled="notDatabase" class="input text-sm">
                         <p class="text-xs text-gray-500 mt-1">Archive expiry: "never" (default) keeps rows forever, or a duration like "720h" prunes older rows.</p>
                     </div>
                     <button type="submit" class="btn-primary text-sm">Add Target</button>

templates/source_logs.html

@@ -23,8 +23,8 @@
     <div class="card">
         <div class="divide-y divide-gray-100">
             {{range .Events}}
-            <div class="p-4" x-data="{ open: false }">
+            <div class="p-4" x-data="collapsible">
-                <div class="flex items-center justify-between cursor-pointer" @click="open = !open">
+                <div class="flex items-center justify-between cursor-pointer" @click="toggle">
                     <div class="flex items-center gap-3">
                         <span class="badge-info">{{.Method}}</span>
                         <span class="text-sm font-mono text-gray-700">{{.ID}}</span>
@@ -43,7 +43,7 @@
                         </span>
                         {{end}}
                         <span class="text-xs text-gray-400">{{.CreatedAt.Format "2006-01-02 15:04:05"}}</span>
-                        <svg class="w-4 h-4 text-gray-400 transition-transform" :class="{ 'rotate-180': open }" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                        <svg class="w-4 h-4 text-gray-400 transition-transform" :class="caretClass" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                             <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7"/>
                         </svg>
                     </div>
@@ -71,8 +71,8 @@
                         <h3 class="text-xs font-medium uppercase tracking-wide text-gray-500">Deliveries</h3>
                         <div class="mt-2 divide-y divide-gray-200">
                             {{range .Deliveries}}
-                            <div class="py-2" x-data="{ attempts: false }">
+                            <div class="py-2" x-data="collapsible">
-                                <div class="flex items-center justify-between cursor-pointer" @click="attempts = !attempts">
+                                <div class="flex items-center justify-between cursor-pointer" @click="toggle">
                                     <div class="flex items-center gap-3">
                                         <span class="text-sm text-gray-700">{{.Target.DisplayName}}</span>
                                         <span class="text-xs {{if eq .Status "delivered"}}text-green-600{{else if eq .Status "failed"}}text-red-600{{else if eq .Status "retrying"}}text-yellow-600{{else}}text-gray-400{{end}}">{{.Status}}</span>
@@ -86,13 +86,13 @@
                                         </form>
                                         {{end}}
                                         <span class="text-xs text-gray-400">{{.AttemptCount}} attempt{{if ne .AttemptCount 1}}s{{end}}</span>
-                                        <svg class="w-3 h-3 text-gray-400 transition-transform" :class="{ 'rotate-180': attempts }" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                                        <svg class="w-3 h-3 text-gray-400 transition-transform" :class="caretClass" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                                             <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7"/>
                                         </svg>
                                     </div>
                                 </div>
 
-                                <div x-show="attempts" x-cloak class="mt-2 space-y-2">
+                                <div x-show="open" x-cloak class="mt-2 space-y-2">
                                     {{if .AttemptsOmitted}}
                                     <p class="text-xs text-gray-500">{{.AttemptsOmitted}} attempt{{if ne .AttemptsOmitted 1}}s{{end}} omitted between the first and last shown.</p>
                                     {{end}}