Files
pj 9ab59365b2 redact passwords only, and say what each step did in the log (#93)
* feat(hierarchy): name the route a native tree shows

The screen name was web-only: the Chrome driver stamps sanderling-screen on
the root and nothing else does, so every Android and iOS step recorded and
logged an empty screen. The route marker the tree already carries (the
resource id ending in Screen, the same one Transitional counts) names it.

* feat(runner): say what each step did in the step log

One line per step carried only an index and a node count. It now names the
screen, the action, its target and the typed value, the last through the
same redaction the trace and the prompt use. Emitted after the apply so the
line reports what actually happened, skip reason included.

* fix(sidecar): state on android whether a field is a secure entry

maestro's tree mapper copies a fixed attribute list off the device's XML and
password is not on it, so no android element ever reported the fact and the
conservative rule downstream redacted every typed value in the trace, the
prompt and the log. The XML still carries it: re-read it once per settled
snapshot and state the fact on the text fields it matches. A field it cannot
match stays unstated, which still reads as a credential.

* docs: correct the record that android never reports a secure field

Four places said android reports the fact for nothing and that every typed
value there is redacted. The sidecar now states it, so they described the
old behaviour.

* test(sidecar): fail the build if maestro renames the call the fact comes from

* fix(sidecar): state the fact on a field named by its hint alone

collectTextFields matched on class only, so a node the go side calls editable
off its hintText was left unstated and its typed value redacted.

* docs: record that ios and web state secure:false for compose password fields

Both derive the fact from a widget type a compose app never has, so the
value reaches the trace in the clear. Verified on folio on both targets.

* feat(android): read the application id out of an apk

parses the compiled AndroidManifest.xml rather than shelling out to
aapt2, which lives in the versioned build-tools directory that hosts
with only platform-tools never install.

Claude-Session: https://claude.ai/code/session_012PVErdr3ZzyUASeVQDWsUc

* feat(cli): let --android-app-path supply the bundle id

--bundle-id stays required everywhere else, and an explicit one still
wins, so the apk can never quietly override what was asked for.

Claude-Session: https://claude.ai/code/session_012PVErdr3ZzyUASeVQDWsUc

* docs: record that the apk can name the package itself

Claude-Session: https://claude.ai/code/session_012PVErdr3ZzyUASeVQDWsUc

* fix(testrun): pass the jvm the flag that silences the jdk 24 unsafe warning

* feat(folio): ask which android device to run on when none is named

* feat(folio): pin ios recipes to one simulator udid and ask when several match

* docs(ci): say how just ios lands on the simulator the boot step chose

* chore(folio): ignore run output anywhere under examples/folio

* refactor(hierarchy): name no screen for a tree Transitional calls a cross-fade

ScreenName kept its own reading of the route markers and disagreed with
Transitional on a marker repeated by a nested node: it named the screen on
a step the runner was skipping as unsettled. One reading now.

* refactor(sidecar): inline the one attempt passed to callViewHierarchy

A named constant and its own comment for a literal used once.

* test(sidecar): compare the whole tree when checking the annotation changes nothing else

The old assertions checked one id string and one bounds value, and passed
with every other attribute stripped off every node. Now the annotated tree
minus the two facts it stated must equal the input.

* fix(sidecar): match a field to its xml node by class as well as id and bounds

A wrapper drawn to the same bounds as the untagged field inside it shared
the field's key, both were dropped as ambiguous, and every value typed into
an untagged field was redacted. The class tells them apart.

* docs(runs): record what the android hierarchy re-read costs per step

Two 1m runs per binary on folio, same seed, before and after the re-read.
2026-09-05 23:54:12 +05:30

13 KiB

name, description
name description
sanderling-setup Get sanderling running against an app that is not folio. Use before writing a spec for a new app, when deciding what test hooks the app needs, and when a run will not start or starts and sees nothing.

Getting sanderling onto your app

The goal of setup is not a run that finishes. It is a run whose output you can believe. Two things decide that, and both are usually treated as chores: the handles the app exposes, and the state the app starts in. Everything else here is plumbing.

Every flag below is one the binary accepts, checked against sanderling test -h on this revision. That command is the authority, not this file and not the manual. Check before you use a flag you have not seen work.

1. Install, then check the host

The CLI installs from the release script, and the spec package from npm:

curl -fsSL https://raw.githubusercontent.com/priyanshujain/sanderling/master/install.sh | bash
npm install --save-dev @sanderling/spec

Both come from the same release tag and the CLI bundles the package's TypeScript when it evaluates your spec, so they move together.

sanderling doctor reports the host's readiness per platform and exits non-zero if anything is missing. Each line names the check and, on a failure, what to do about it. On a Mac with the Android SDK installed but a CLI built by a plain go build, sanderling doctor --platform android says:

OK    adb on PATH or under the Android SDK
OK    emulator on PATH or under the Android SDK
OK    java 17+ on PATH
FAIL  sidecar JAR is real (not placeholder): placeholder JAR embedded; run `make sidecar && make sanderling` to embed the real fat JAR
error: 1 check(s) failed

Scope it with --platform web|android|ios|ios-device|all (default all). Web needs a Chromium that launches headless. Android needs adb, an emulator, Java 17 or newer, and the embedded sidecar JAR. iOS needs xcrun and simctl; ios-device adds devicectl, the macOS usbmuxd socket, a connected paired device, and App Store Connect signing credentials.

The adb and emulator checks resolve through the same helpers a run uses, so they search PATH, then ANDROID_HOME and ANDROID_SDK_ROOT, then ~/Library/Android/sdk, ~/Android/Sdk and the Homebrew command-line-tools paths. A host the doctor passes is a host a run can drive, and a failure names every location it tried. What the doctor cannot tell you is the reverse: a missing SDK can also surface during a run as sidecar health check: context deadline exceeded about thirty seconds in, which names the symptom and not the cause (issue #69). If you see it, go back to sanderling doctor --platform android before believing anything about the sidecar.

Two traps if you build from source rather than installing a release. A plain go build ./cmd/sanderling embeds a placeholder sidecar JAR, so every Android run stops at sidecar: binary built without -tags withsidecar; make sanderling (or make sanderling-android) embeds the real one. And go run ./cmd/sanderling test collapses the process exit code: a run that exits 2 comes back from go run as 1 with exit status 2 printed. Use the built binary whenever the exit code matters, which is always in CI.

2. Point it at the app

Android takes the applicationId, boots an AVD with --avd, and picks between attached devices with --device <serial> as adb devices prints it:

sanderling test --spec spec.ts --bundle-id com.example.app --avd Pixel_7_API_34

--android-app-path <apk> stands in for --bundle-id: the applicationId is read out of the APK's compiled manifest, so the id and the file it came from cannot disagree.

iOS takes --platform ios and --ios-device, which accepts a simulator name or UDID, or a connected device's name, UDID, or CoreDevice id. --ios-app-path points at the .app bundle and is what makes clear-state real; see section 4.

Web takes a URL as the bundle id:

sanderling test --spec spec.ts --platform web --bundle-id http://127.0.0.1:8799/index.html

The web target has to genuinely load. A page that boots to a blank canvas still produces steps, still exits 0, and proves nothing: folio's own web leg needs COOP/COEP headers or its sqlite worker never starts, which is why .github/scripts/folio-run.sh serves the build itself instead of using a stock static server. Confirm the app rendered before you read anything else.

3. Test hooks are a prerequisite, not a polish step

This is the part that decides whether a spec is possible at all. The header of replay-ui/sanderling/spec.ts states it as the lesson it is:

The hooks it drives (data-testid, data-step, ...) were added to the UI for this spec. Needing them is the lesson: a UI with no stable handles is a UI nothing can assert on, and that is as true for a person writing a test as it is for a fuzzer.

A fuzzer is not asking for anything a human test author does not need. It is only less able to squint at a screenshot and guess. Budget the hooks as part of adopting sanderling, before the spec, not after the first vacuous run.

testTag is the portable name. internal/hierarchy/hierarchy.go aliases it to resource-id, identifier and accessibilityIdentifier, so one selector matches on every platform. What you have to add differs:

Compose on Android. Modifier.testTag("AddAccountSubmit") alone does not reach the accessibility tree. The tree only carries it when a root composable sets semantics { testTagsAsResourceId = true }. folio does this once, at the app root, through an expect/actual bridge: examples/folio/app/shared/src/androidMain/kotlin/app/folio/ui/TestTagBridge.android.kt. Without it every testTag selector matches nothing, every property over it declines, and the run goes green having checked nothing.

Web. data-testid is the hook. Every data-* attribute on the element reaches the spec under attrs, camel-cased the way dataset does it, so data-step-count reads as attrs.stepCount. That is how the replay-ui spec reads a panel's own claim about which step it is showing rather than re-deriving it. Hooks that carry a value, not just an identity, are what make cross-panel agreement properties possible.

iOS. accessibilityIdentifier, set via .accessibilityIdentifier in SwiftUI or UIKit. Compose Multiplatform maps testTag to it for you.

Two rules about the names themselves. On Android and iOS a testTag selector falls through to a substring compare, so {testTag: "Sub"} matches AddAccountSubmit; on web the same selector compiles to an exact CSS attribute match and hits nothing. Make each hook a whole distinct name rather than a fragment of another, and you are right on both. And give every screen a marker of its own, because a route extractor is what lets a property decline on the screens it has nothing to say about.

The check that a hook exists is not that you added it. It is that you can point at a step in a real trace where a selector over it resolved to a value. sanderling-spec-authoring covers which hooks a spec needs and in what order to add them; this section is about what each platform requires before any of that reaches the tree.

4. A run must start from a known state

--clear-data defaults to true and is the difference between a repeatable run and a measurement of your own leftovers. A second run that inherits the first one's accounts, cache and completed onboarding diverges at step 1: the seed reproduces nothing, the two runs' step counts are not comparable, and any number you quote from the pair is noise.

What "clear" reaches depends on the platform, and in two cases it silently reaches less than you expect:

  • Android wipes app data through the sidecar. On OEM builds that deny pm clear, pass --android-app-path <apk> and it uninstalls and reinstalls instead.
  • iOS simulator without --ios-app-path resets the data container only and prints clear-state requested without an app path: resetting the data container only. With the path it does a full simctl uninstall and install. The container wipe is a real reset and folio's own iOS leg relies on it; the reinstall path is the one that races FrontBoard.
  • iOS on a physical device without --ios-app-path does not clear at all. It prints clear-state on a physical device requires --ios-app-path for a reinstall; skipping (state not cleared) and carries on. A device run left on the default flag inherits every previous run's data.
  • Web clears cookies and the target origin's storage. It cannot touch your backend. If your app's state lives on a server, reset it yourself between runs.

--clear-data=false is a legitimate choice in one situation: you have just installed a fresh build, so the app is already in clear state and an in-run reinstall would only add a failure mode. Outside that, a run that resumes is a run you cannot repeat.

5. The device does not have to be local

Android talks to whatever adb server the environment names. ADB_SERVER_SOCKET=tcp:host:port (or tcp:port for a server on this machine) is read first, then the older ANDROID_ADB_SERVER_ADDRESS and ANDROID_ADB_SERVER_PORT pair, then the loopback default. The CLI shells out to adb and inherits it; the JVM sidecar resolves the same variables when it attaches to a serial.

Two things to get right. Pass --device <serial> exactly as the remote server reports it: with no serial the sidecar's target is a local localhost:5555, not your remote device. And a serial that already looks like host:port is dialled straight at adbd, bypassing any server, which is a different path with different failure modes. A value the sidecar cannot parse fails the run rather than falling back to loopback, and that is deliberate: emulator serials are numbered per server, so a quiet fallback would drive whatever this machine calls emulator-5554 and report the results as the remote device's.

6. What a first run prints

A ten step web run, in full:

bundled spec: 16532 bytes (sha256=71375ed5bfc7)
bundled web spec: 33131 bytes (sha256=779bae3c8fee)
spec loaded into verifier
trace dir: runs/20260815-172356
running for 1m30s or 10 steps, whichever comes first (seed=7)
step index=1 screen="/index.html" nodes=6
...
step index=10 screen="/index.html" nodes=6

elapsed: 1.715s

run complete: 10 steps, 10 driven by the generator
no violations.

nodes= is the first number to read and the cheapest lie detector you have. On that page, four elements plus html and body gave nodes=6. The same command against an empty page gives nodes=2 for every step, and the run then refuses itself: the generator has nothing to pick, so the summary reads run complete: 10 steps, 0 driven by the generator and 10 action(s) never reached the app: no_action_produced 10, and the process exits 1 having judged one blank screen ten times. If nodes is a handful and never grows, the run is looking at something that is not your app.

screen= is web-only and has nothing to do with your spec's screen hooks: the Chrome driver puts the URL hash, or the pathname when there is no hash, on the root node, and only that driver writes the attribute. On Android and iOS it is empty on every step, so an empty screen= there is the normal reading and not a symptom. On web, a screen= that never changes means the run never left one URL, which for a single-page app that routes in memory is also normal. Your spec's own route extractor is the thing to trust on every platform.

The summary can carry a third line you should never skim past:

7 step(s) judged by nothing: the screen was still moving when it was read

Those steps were recorded but no property judged them, so the run's step count and its checked count are different numbers. sanderling-run-triage is about what to do with that.

Set --max-steps whenever you intend to compare two runs: a step budget is what makes them comparable, since duration alone does not. --seed fixes the PRNG, and seed 0 draws a random one and records it in meta.json.

7. The run directory

Each run writes <output>/<UTC timestamp>/, containing meta.json, trace.jsonl, and one PNG per step under screenshots/. --output defaults to ./runs.

meta.json is the run's identity: seed, spec path, bundled spec sha256, platform, bundle id, start and end times, generator, max_steps, duration_millis, host, and the --arm label if you set one. Two runs that differ in any of those are different runs and cannot be pooled.

If the app never launched, there is no run directory at all: the launch error comes before the trace is created. error: launch app: ... with nothing under ./runs means the run never began, which is a different thing from a run that began and found nothing.

Open a run with sanderling replay <dir>, which accepts either the parent runs directory or a single run directory.

Reporting

Say what you actually ran and what came back: the doctor output you got rather than the one you expected, the exact sanderling test command, the step count and the nodes= figure from the first run, and for each hook you added, the step in a real trace where a selector over it resolved. Name what you could not establish, particularly any platform you did not run on.

Setup is finished when a property can be written that could fail. Write it with sanderling-spec-authoring, review it with sanderling-spec-review, and read the run it produces with sanderling-run-triage.