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 browser test in internal/server, built only with the browser tag, loads the webhook page and the event log under the real headers. make test-browser runs it in Docker, in a digest-pinned headless browser image (Dockerfile.browser). Model: opus-5-5
2026-10-02 08:37:11 +00:00
20 changed files with 632 additions and 172 deletions
@@ -26,7 +26,7 @@ COPY . .
 # Dockerfile.lint, including --network=none (see its header for why).
 RUN make fmt-check
 RUN --network=none golangci-lint config verify --config .golangci.yml
-RUN --network=none golangci-lint run --config .golangci.yml ./...
+RUN --network=none golangci-lint run --config .golangci.yml --build-tags browser ./...

 # Build stage
 # golang:1.26.1-bookworm (Debian-based), 2026-03-17
@@ -0,0 +1,29 @@
+# Browser test image, built by script/test-browser (make test-browser). It
+# runs the test in internal/server that loads the pages in a headless
+# browser under the real Content-Security-Policy. That test is built only
+# with the browser build tag, so make test leaves it out. Here the browser
+# comes from a digest-pinned image, and if it is missing the test fails.
+
+# golang:1.26.1-bookworm, 2026-03-17: the builder stage's image in Dockerfile.
+FROM golang:1.26.1-bookworm@sha256:4465644228bc2857a954b092167e12aa59c006a3492282a6c820bf4755fd64a4 AS build
+
+WORKDIR /src
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+
+# The test binary embeds the templates and static files, so the browser
+# stage needs nothing else. -p 4 keeps the compile's memory down, as in
+# script/test.
+RUN make assets && go test -c -p 4 -tags browser -o /browser.test ./internal/server
+
+# chromedp/headless-shell:151.0.7922.109 (Debian trixie), 2026-08-11. The
+# browser is on PATH as headless-shell, where the test's browser library
+# looks for it.
+FROM chromedp/headless-shell:151.0.7922.109@sha256:2d349b544a1ea6b5b5fd7c0fe99215ff662339c57407ee2e8c0a11af93516b04 AS browser
+
+COPY --from=build /browser.test /browser.test
+
+RUN /browser.test -test.v -test.timeout 90s -test.run '^TestAlpineRunsUnderTheSecurityPolicy$'
@@ -34,4 +34,6 @@ COPY . .
 # `run` silently ignores config keys it does not recognize, so a typo would
 # disable a setting without a word. `config verify` is what catches that.
 RUN --network=none golangci-lint config verify --config .golangci.yml
-RUN --network=none golangci-lint run --config .golangci.yml ./...
+# --build-tags browser also lints the browser test, which is built only with
+# that tag (make test-browser).
+RUN --network=none golangci-lint run --config .golangci.yml --build-tags browser ./...
@@ -1,4 +1,4 @@
-.PHONY: bootstrap setup assets test lint fmt fmt-check check build run dev deps docker clean hooks css version
+.PHONY: bootstrap setup assets test test-browser lint fmt fmt-check check build run dev deps docker clean hooks css version

 # Default target
 .DEFAULT_GOAL := check
@@ -33,6 +33,9 @@ assets:
 test:
 	@script/test

+test-browser:
+	@script/test-browser
+
 lint:
 	@script/lint

@@ -19,8 +19,8 @@ before deploying one.
 ### Prerequisites

 - Go 1.26.1+ (the version in `go.mod`)
- Docker (for linting, for the test stage of the CI gate, and for
-  containerized deployment)
+- Docker (for linting, for the browser test, for the test stage of the
+  CI gate, and for containerized deployment)

 golangci-lint is not a prerequisite and must not be installed on the
 host: `script/bootstrap` does not install it, and `make lint` runs the
@@ -58,6 +58,7 @@ make fmt        # Format code (gofmt + goimports)
 make fmt-check  # Fail if gofmt would change anything (writes nothing)
 make lint       # Run golangci-lint in Docker (Dockerfile.lint)
 make test       # Run tests with race detection
+make test-browser # Run the browser test in Docker (Dockerfile.browser)
 make check      # test + lint + fmt-check (CI gate)
 make build      # Build binary to bin/webhooker (version-stamped)
 make version    # Print the version this checkout would stamp
@@ -1240,7 +1241,7 @@ What that means for an operator:
 This repository adheres to the
 [Scripts to Rule Them All](https://github.com/github/scripts-to-rule-them-all)
 standard: normalized scripts in `script/` are the entrypoints for the
-development workflow. Ten of the Makefile's seventeen targets are thin
+development workflow. Eleven of the Makefile's eighteen targets are thin
 shims that call them; `build`, `run`, `dev`, `deps`, `clean`, `css` and
 `version` are inline commands with no script behind them, though `build`,
 `run` and `dev` first run `script/assets`, and `build` and `version` both
@@ -1261,6 +1262,8 @@ We provide:
 - `script/assets` — extract Alpine.js from its tarball in `3p/` (see
  [Third-party browser assets](#third-party-browser-assets))
 - `script/test` — run the test suite
+- `script/test-browser` — run the browser test in Docker (see
+  [Third-party browser assets](#third-party-browser-assets))
 - `script/lint` — run golangci-lint in Docker (see Linting below)
 - `script/fmt` — format all code (writes)
 - `script/fmt-check` — check formatting (read-only)
@@ -1281,9 +1284,30 @@ We provide:

 ## Third-party browser assets

-The web UI serves one third-party script, Alpine.js. Its npm package tarball
-is committed as `3p/alpinejs-3.14.9.tgz`, byte for byte as the npm registry
-publishes it. It is a dependency, not this repo's build output, so
+The web UI serves one third-party script, Alpine.js, in its CSP build: the npm
+package `@alpinejs/csp`. The pages' Content-Security-Policy forbids eval, which
+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 webhook page and the event log
+under the real policy and checks that: both add forms stay hidden until Add is
+clicked; choosing Slack in the add target form leaves the HTTP fields out of
+what it submits, also after leaving the page and going back to it, when the
+browser restores the choice; an event expands and collapses, and so do a
+delivery's attempts inside it; and at phone width the menu button opens and
+closes the mobile menu. It also fails if the browser reports a console warning
+or error, an uncaught exception, or anything the policy refused. It is not part
+of `make test`, `make check` or the image build (its file is built only with the
+`browser` build tag). Run it with `make test-browser` after changing
+`templates/` or `static/js/`: that builds `Dockerfile.browser`, which runs the
+test in a digest-pinned headless browser image, so the host needs no browser.
+
+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.
@@ -1296,10 +1320,11 @@ 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/`
-with it, update its file name in `script/assets`, and run `make check`.
+`https://registry.npmjs.org/@alpinejs/csp/<version>`, replace the tarball in
+`3p/` with it as `alpinejs-csp-<version>.tgz`, update its file name in
+`script/assets`, and run `make check`.

 ## Rationale

@@ -2831,7 +2856,7 @@ 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/
@@ -2925,13 +2950,14 @@ 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/alpine.min.js       # Alpine.js, extracted from 3p/ by make assets, not committed
+│   ├── js/app.js              # Copy-to-clipboard, and the Alpine.js components
+│   └── 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
 ├── Dockerfile.lint            # Lint-only image built by script/lint
-├── Makefile                   # 10 of 17 targets shim script/; 7 are inline
+├── Dockerfile.browser         # Browser test image built by script/test-browser
+├── Makefile                   # 11 of 18 targets shim script/; 7 are inline
 ├── go.mod / go.sum
 └── .golangci.yml              # Linter configuration
 ```
@@ -2979,10 +3005,10 @@ Applied to all routes in this order:
 2. **SecurityHeaders** — Production security headers on every response
   (HSTS, X-Content-Type-Options, X-Frame-Options, CSP, Referrer-Policy,
   Permissions-Policy)
-3. **Metrics** — Prometheus HTTP metrics (if `METRICS_USERNAME` and
-   `METRICS_PASSWORD` are both set)
-4. **Logging** — Structured request logging (method, URL, status,
+3. **Logging** — Structured request logging (method, URL, status,
   latency, remote IP, user agent, request ID)
+4. **Metrics** — Prometheus HTTP metrics (if `METRICS_USERNAME` and
+   `METRICS_PASSWORD` are both set)
 5. **CORS** — Cross-origin resource sharing headers
 6. **Timeout** — 60-second request timeout
 7. **Recoverer** — Panic recovery: one `ERROR` record through
@@ -3002,10 +3028,6 @@ local record instead of nothing. What that placement gives up is
 recovery of a panic in the six entries above it, none of which does
 more than set a header or start a timer.

-Metrics sits outside Logging so that a handler's flush reaches the
-client: go-http-metrics' writer passes a flush on only when the writer
-inside it has a `Flush` method, and the access log's writer has none.
-
 Each admin page route group (`/pages`, `/user/*`, `/hooks`,
 `/hook/*`) starts with its own **Recoverer** and, if `SENTRY_DSN` is
 set, its own **Sentry** error reporting. That Recoverer answers a panic
@@ -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
@@ -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 v0.37.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/sys v0.47.0 h1:o7XGOvZQCADBQQ4Y7VNq2dRWQR7JmOUW8Kxx4ZsNgWs=
+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=
@@ -233,13 +233,6 @@ func (lrw *loggingResponseWriter) WriteHeader(code int) {
 	lrw.ResponseWriter.WriteHeader(code)
 }

-// Unwrap lets http.ResponseController reach the writer underneath, so
-// a handler can still flush or set a write deadline through the access
-// log.
-func (lrw *loggingResponseWriter) Unwrap() http.ResponseWriter {
-	return lrw.ResponseWriter
-}
-
 // concreteLogURL renders the request's own URL for the access log
 // branches that keep it, with the query string replaced by a fixed
 // marker.
@@ -627,9 +627,11 @@ func TestRecovererIgnoresANonPanickingHandler(t *testing.T) {
 // net/http's own writer from http.ResponseController, so a handler
 // that flushes or sets a deadline starts failing.
 //
-// The recoverer is the only middleware in the chain here;
-// TestFlushThroughProductionRouter in internal/server covers the
-// shipped chain.
+// The recoverer is the only middleware in the chain here. The access
+// logger's own wrapper does not implement Unwrap, so a chain
+// containing it fails this regardless of what the recoverer does;
+// what is being pinned is that the recoverer adds no such opacity of
+// its own.
 func TestRecovererKeepsResponseControllerWorking(t *testing.T) {
 	t.Parallel()

@@ -0,0 +1,391 @@
+//go:build browser
+
+// This test needs a headless browser, so it is built only with the
+// browser build tag: `make test` leaves it out, and `make test-browser`
+// runs it in the browser image that Dockerfile.browser pins.
+
+package server_test
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"slices"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/chromedp/cdproto/log"
+	"github.com/chromedp/cdproto/network"
+	"github.com/chromedp/cdproto/runtime"
+	"github.com/chromedp/chromedp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/gorm/clause"
+	"sneak.berlin/go/webhooker/internal/database"
+)
+
+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
+
+	// The window size of a phone, narrow enough that the pages show
+	// the mobile menu button instead of the navigation links.
+	phoneWidth  = 390
+	phoneHeight = 844
+)
+
+// TestAlpineRunsUnderTheSecurityPolicy loads the webhook page and the
+// event log in a headless browser, 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, problems := 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"}`)
+	target := env.seedTarget(t, webhook.ID)
+	dlv := env.seedFailedDelivery(t, webhook.ID, event.ID, target.ID)
+
+	webhookDB, err := env.dbMgr.GetDB(webhook.ID)
+	require.NoError(t, err)
+	require.NoError(t, webhookDB.Omit(clause.Associations).Create(
+		&database.DeliveryResult{
+			DeliveryID: dlv.ID,
+			AttemptNum: 1,
+			StatusCode: http.StatusBadGateway,
+		},
+	).Error)
+
+	require.NoError(t, chromedp.Run(
+		ctx, setCookies(srv.URL, env.authCookies(t, userID, "browser")),
+	))
+
+	page := srv.URL + "/hook/" + webhook.ID
+
+	checkAddForms(ctx, t, page)
+	checkTargetType(ctx, t, page+"/events")
+	checkEventLog(ctx, t, page+"/events", event.ID, target.Name)
+	checkMobileMenu(ctx, t, page)
+
+	assert.Empty(t, problems(), "the browser reported problems")
+}
+
+// startBrowser starts a headless browser for one test. It returns the
+// context that drives it, and a function listing what the browser
+// reported going wrong on its pages: console warnings and errors,
+// which is how Alpine.js reports an expression it cannot run; uncaught
+// exceptions; and every entry in the browser's own security log, which
+// is where it reports each script, style, image or request the
+// Content-Security-Policy refused.
+//
+// The browser library finds the browser on PATH. Without one the first
+// chromedp.Run fails, and with it the test.
+func startBrowser(t *testing.T) (context.Context, func() []string) {
+	t.Helper()
+
+	allocCtx, cancelAlloc := chromedp.NewExecAllocator(
+		t.Context(),
+		append(
+			chromedp.DefaultExecAllocatorOptions[:],
+			// Dockerfile.browser runs the test as root, where the
+			// browser'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()
+		case *log.EventEntryAdded:
+			if ev.Entry.Source != log.SourceSecurity {
+				return
+			}
+
+			problem = ev.Entry.Text
+		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 elements matching a CSS
+// selector or an XPath expression to be rendered, and reports whether
+// they were. 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.BySearch),
+	) == nil
+}
+
+// hidden is shown's opposite: it waits for the elements 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.BySearch),
+	) == nil
+}
+
+// click clicks the 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.
+//
+// It then opens the page at elsewhere and goes back. The browser loads
+// the webhook page again and restores the form as it was left, Slack
+// chosen, without a change event; the form must again show and submit
+// Slack's fields, not the HTTP ones.
+func checkTargetType(ctx context.Context, t *testing.T, elsewhere string) {
+	t.Helper()
+
+	const (
+		chooseSlack = `(() => {
+			const type = document.querySelector('select[name="type"]');
+			type.value = "slack";
+			type.dispatchEvent(new Event("change"));
+		})()`
+		chosen    = `document.querySelector('select[name="type"]').value`
+		howLoaded = `performance.getEntriesByType("navigation")[0].type`
+		submitted = `[...new FormData(
+			document.querySelector('form[action$="/targets"]')).keys()]`
+		slackURL = `input[placeholder^="https://hooks.slack.com/"]`
+		httpURL  = `input[placeholder="https://example.com/webhook"]`
+	)
+
+	slackFields := strings.Fields("csrf_token name type max_retries url")
+
+	var fields []string
+
+	require.NoError(t, chromedp.Run(
+		ctx,
+		chromedp.Evaluate(chooseSlack, nil),
+		chromedp.Evaluate(submitted, &fields),
+	))
+
+	assert.Equal(
+		t, slackFields, fields,
+		"with Slack chosen, the HTTP fields must not be submitted",
+	)
+
+	var loaded, restored string
+
+	// Going back waits for the load event, after which the browser has
+	// restored the form.
+	require.NoError(t, chromedp.Run(
+		ctx,
+		loadPage(elsewhere),
+		chromedp.NavigateBack(),
+		chromedp.WaitNotPresent("[x-cloak]", chromedp.ByQuery),
+		chromedp.Evaluate(howLoaded, &loaded),
+		chromedp.Evaluate(chosen, &restored),
+	))
+
+	// A page the browser kept in memory and showed again as it was
+	// would prove nothing here.
+	require.Equal(
+		t, "back_forward", loaded,
+		"going back, the browser did not load the page again",
+	)
+	require.Equal(
+		t, "slack", restored,
+		"going back, the browser did not restore the chosen type",
+	)
+
+	click(ctx, t, `//h2[text()="Targets"]/following-sibling::button`)
+
+	assert.True(t, shown(ctx, slackURL),
+		"going back with Slack chosen, the Slack fields are not shown")
+	assert.True(t, hidden(ctx, httpURL),
+		"going back with Slack chosen, the HTTP fields are shown")
+
+	require.NoError(t, chromedp.Run(
+		ctx, chromedp.Evaluate(submitted, &fields),
+	))
+
+	assert.Equal(
+		t, slackFields, fields,
+		"going back with Slack chosen, the HTTP fields must not be submitted",
+	)
+}
+
+// checkEventLog loads the event log and checks that clicking an event's
+// row expands it, that in there clicking its delivery shows the
+// delivery's attempts and clicking again hides them, and that clicking
+// the event's row again collapses it.
+func checkEventLog(
+	ctx context.Context, t *testing.T, url, eventID, targetName string,
+) {
+	t.Helper()
+
+	// The event's row shows its ID, and its Resubmit form is in the part
+	// that expands. The delivery's row there shows the target's name.
+	eventRow := `//span[text()="` + eventID + `"]`
+	expanded := `form[action$="/resubmit"]`
+	deliveryRow := `//span[text()="` + targetName + `"]`
+	attempt := `//span[text()="Attempt 1"]`
+
+	require.NoError(t, chromedp.Run(ctx, loadPage(url)))
+
+	assert.True(t, hidden(ctx, expanded), "the event starts expanded")
+
+	click(ctx, t, eventRow)
+	assert.True(t, shown(ctx, expanded), "clicking the event does not expand it")
+
+	assert.True(t, hidden(ctx, attempt), "the delivery's attempts start shown")
+
+	click(ctx, t, deliveryRow)
+	assert.True(t, shown(ctx, attempt),
+		"clicking the delivery does not show its attempts")
+
+	click(ctx, t, deliveryRow)
+	assert.True(t, hidden(ctx, attempt),
+		"clicking the delivery again does not hide its attempts")
+
+	click(ctx, t, eventRow)
+	assert.True(t, hidden(ctx, expanded),
+		"clicking the event again does not collapse it")
+}
+
+// checkMobileMenu loads a page in a phone-sized window and checks that
+// the menu button opens and closes the mobile menu.
+func checkMobileMenu(ctx context.Context, t *testing.T, url string) {
+	t.Helper()
+
+	// The menu button is the only button directly in the navigation
+	// bar's top row. Profile is a link only the mobile menu has.
+	button := `//nav/div/button`
+	menu := `//nav//a[text()="Profile"]`
+
+	require.NoError(t, chromedp.Run(
+		ctx,
+		chromedp.EmulateViewport(phoneWidth, phoneHeight),
+		loadPage(url),
+	))
+
+	assert.True(t, hidden(ctx, menu), "the mobile menu starts open")
+
+	click(ctx, t, button)
+	assert.True(t, shown(ctx, menu), "the menu button does not open the menu")
+
+	click(ctx, t, button)
+	assert.True(t, hidden(ctx, menu), "the menu button does not close the menu")
+}
@@ -1,96 +0,0 @@
-package server_test
-
-import (
-	"net/http"
-	"net/http/httptest"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"sneak.berlin/go/webhooker/internal/config"
-	"sneak.berlin/go/webhooker/internal/server"
-)
-
-// TestFlushThroughProductionRouter drives http.ResponseController.Flush
-// through the shipped router and checks that the flush reaches the
-// writer the server handed in.
-//
-// Every middleware that wraps the writer has to pass a flush through,
-// with an Unwrap method or a Flush of its own. One that does neither
-// makes Flush return http.ErrNotSupported, or do nothing at all when
-// the wrapper outside it only looks for a Flush method, and the
-// handler that trips over it is far from the cause.
-//
-// It runs once with the defaults and once with metrics and Sentry on,
-// because those two add middleware to the chain, and through both the
-// global middleware and an admin page route group, which adds its own.
-func TestFlushThroughProductionRouter(t *testing.T) {
-	t.Parallel()
-
-	cases := []struct {
-		name          string
-		cfg           func(t *testing.T) *config.Config
-		sentryEnabled bool
-	}{
-		{
-			name: "defaults",
-			cfg: func(t *testing.T) *config.Config {
-				t.Helper()
-
-				return &config.Config{
-					DataDir:     t.TempDir(),
-					Environment: config.EnvironmentDev,
-				}
-			},
-		},
-		{
-			name: "metrics and Sentry on",
-			cfg: func(t *testing.T) *config.Config {
-				t.Helper()
-
-				return metricsConfig(t, metricsUser, metricsAuthValue)
-			},
-			sentryEnabled: true,
-		},
-	}
-
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			env := newTestEnvWithConfig(t, tc.cfg(t))
-
-			var flushErr error
-
-			probe := func(w http.ResponseWriter, _ *http.Request) {
-				flushErr = http.NewResponseController(w).Flush()
-			}
-
-			routers := map[string]http.Handler{
-				server.ProbePattern: server.NewRouterWithProbeForTest(
-					env.log.Get(), env.cfg, env.mw, env.hnd,
-					tc.sentryEnabled, probe,
-				),
-				server.PageProbePattern: server.NewRouterWithPageProbeForTest(
-					env.log.Get(), env.cfg, env.mw, env.hnd,
-					tc.sentryEnabled, probe,
-				),
-			}
-
-			for path, router := range routers {
-				flushErr = nil
-
-				w := httptest.NewRecorder()
-				router.ServeHTTP(w, httptest.NewRequestWithContext(
-					t.Context(), http.MethodGet, path, nil,
-				))
-
-				require.NoError(t, flushErr, path)
-				assert.True(
-					t, w.Flushed,
-					"%s: the flush must reach the server's writer", path,
-				)
-			}
-		})
-	}
-}
@@ -61,21 +61,16 @@ func (s *Server) SetupRoutes() {
 func (s *Server) setupGlobalMiddleware() {
 	s.router.Use(middleware.RequestID)
 	s.router.Use(s.mw.SecurityHeaders())
+	s.router.Use(s.mw.Logging())

 	// Metrics recording middleware, registered only when the
 	// endpoint that exposes what it records is served. The
 	// condition is the same MetricsAuthEnabled the /metrics mount
 	// in setupRoutes reads.
-	//
-	// It goes outside Logging. go-http-metrics' writer passes a flush
-	// on only when the writer inside it has a Flush method, and the
-	// access log's writer has none, so inside Logging a handler's
-	// flush would silently do nothing.
 	if s.params.Config.MetricsAuthEnabled() {
 		s.router.Use(s.mw.Metrics())
 	}

-	s.router.Use(s.mw.Logging())
 	s.router.Use(s.mw.CORS())
 	s.router.Use(middleware.Timeout(requestTimeout))

@@ -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
-# extracted file is not committed. script/test, make build and make dev run
-# this first.
+# in 3p/, to static/js/alpine.min.js, where go:embed reads it. The package
+# is @alpinejs/csp, Alpine's build for pages whose Content-Security-Policy
+# 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
 }

@@ -0,0 +1,23 @@
+#!/bin/sh
+# script/test-browser: run the browser test in internal/server. It runs in
+# Docker: Dockerfile.browser builds the test and runs it in a digest-pinned
+# headless browser image, so the host needs no browser.
+#
+# --no-cache-filter=browser runs the test again even when nothing changed;
+# it must name the stage in Dockerfile.browser that runs it.
+# --output=type=cacheonly leaves no image behind to clean up.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    docker build \
+        -f Dockerfile.browser \
+        --no-cache-filter=browser \
+        --progress=plain \
+        --output=type=cacheonly \
+        .
+}
+
+main "$@"
@@ -57,3 +57,73 @@
        init();
    }
 })();
+
+// Alpine.js components.
+//
+// The pages' Content-Security-Policy forbids eval, so the UI loads
+// Alpine's CSP build, which cannot run expressions written in the
+// markup: a directive in templates/ may only name a property or method,
+// and each x-data names a component registered here. This script runs
+// before Alpine, whose script tag is deferred, so this listener is in
+// place when Alpine starts.
+document.addEventListener("alpine:init", function () {
+    "use strict";
+
+    // Something a click shows and hides: the mobile menu, an add form,
+    // an event in the event log, a delivery's attempts.
+    window.Alpine.data("collapsible", function () {
+        return {
+            open: false,
+            toggle() {
+                this.open = !this.open;
+            },
+            get closed() {
+                return !this.open;
+            },
+            // Turns a downward caret up while open.
+            get caretClass() {
+                return { "rotate-180": this.open };
+            },
+        };
+    });
+
+    // The add target form. Only the chosen type's fields show, and the
+    // others are disabled so that the form does not submit them.
+    //
+    // The type is read from the type select when Alpine starts, when the
+    // select changes, and on pageshow. Going back to the page, the
+    // browser restores the type chosen before without a change event,
+    // in some browsers only after Alpine has started, but always before
+    // pageshow.
+    window.Alpine.data("targetForm", function () {
+        return {
+            targetType: "",
+            init() {
+                this.readType();
+            },
+            readType() {
+                this.targetType = this.$root.querySelector(
+                    'select[name="type"]'
+                ).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;
+            },
+        };
+    });
+});
@@ -1,5 +1,5 @@
 {{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>
@@ -7,9 +7,9 @@

        <!-- Mobile menu button -->
        {{if .User}}
-        <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>
@@ -7,7 +7,7 @@
     event log, the navbar and the footer, so an entrypoint URL fits on
     one line. An inline style, because the committed tailwind.css has
     no class this wide. -->
-<div class="mx-auto px-6 py-8" style="max-width: 108rem" x-data="{ showAddEntrypoint: false, showAddTarget: false }">
+<div class="mx-auto px-6 py-8" style="max-width: 108rem">
    <div class="mb-6">
        <a href="/hooks" class="text-sm text-primary-600 hover:text-primary-700">&larr; Back to webhooks</a>
        <div class="flex flex-wrap justify-between items-center gap-2 mt-2">
@@ -32,10 +32,10 @@

    <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>
@@ -44,7 +44,7 @@
            </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="/hook/{{.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">
@@ -91,10 +91,10 @@
        </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>
@@ -103,42 +103,42 @@
            </div>

            <!-- Add target form -->
-            <div x-show="showAddTarget" x-cloak class="p-4 bg-gray-50 border-b border-gray-200">
-                <form method="POST" action="/hook/{{.Webhook.ID}}/targets" x-data="{ targetType: 'http' }" class="space-y-3">
+            <div x-show="open" x-cloak class="p-4 bg-gray-50 border-b border-gray-200">
+                <form method="POST" action="/hook/{{.Webhook.ID}}/targets" x-data="targetForm" @pageshow.window="readType" 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="readType" 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'">
-                        <input type="url" name="url" placeholder="https://example.com/webhook" :disabled="targetType !== 'http'" class="input text-sm">
+                    <div x-show="isHttp">
+                        <input type="url" name="url" placeholder="https://example.com/webhook" :disabled="notHttp" class="input text-sm">
                    </div>
-                    <div x-show="targetType === 'http'">
-                        <textarea name="headers" rows="3" placeholder="Authorization: Bearer ..." :disabled="targetType !== 'http'" class="input text-sm"></textarea>
+                    <div x-show="isHttp">
+                        <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'">
-                        <input type="url" name="url" placeholder="https://hooks.slack.com/services/..." :disabled="targetType !== 'slack'" class="input text-sm">
+                    <div x-show="isSlack">
+                        <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'">
-                        <input type="text" name="expiry" placeholder="never" :disabled="targetType !== 'database'" class="input text-sm">
+                    <div x-show="isDatabase">
+                        <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>
@@ -15,8 +15,8 @@
    <div class="card">
        <div class="divide-y divide-gray-100">
            {{range .Events}}
-            <div class="p-4" x-data="{ open: false }">
-                <div class="flex items-center justify-between cursor-pointer" @click="open = !open">
+            <div class="p-4" x-data="collapsible">
+                <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>
@@ -35,7 +35,7 @@
                        </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>
@@ -63,8 +63,8 @@
                        <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="flex items-center justify-between cursor-pointer" @click="attempts = !attempts">
+                            <div class="py-2" x-data="collapsible">
+                                <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>
@@ -78,13 +78,13 @@
                                        </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}}