limrun-maestro-testing

Maestro on Limrun iOS

Run the stock upstream Maestro CLI against a remote Limrun iOS simulator. lim ios maestro wires maestro test to the instance transparently: it installs and launches the Maestro XCTest runner on the simulator when needed, then routes the driver traffic to it. No fork of Maestro, no local simulator, no local Xcode.

Prerequisites

• lim CLI 0.22.0 or newer: npm install --global lim. Auth is lim login or LIM_API_KEY (it may already be set in the user's environment even when .env and the shell do not show it; check before asking for it).
• Maestro CLI on PATH: curl -fsSL https://get.maestro.mobile.dev | bash. Maestro needs Java 17+ (java -version to check). Both Maestro 2.5.x and 2.6+ work; lim adapts to the installed version automatically.

The CLI is the source of truth: if a flag errors or you need one not shown here, check lim ios <subcommand> --help instead of guessing.

Verify the setup

Before touching the user's app, prove the whole pipeline with a flow against the built-in Settings app; it needs no app install, tunnel, or build:

ID=$(lim ios create --install-asset appstore/maestro-ios-runner-2.5.1.tar.gz \
  --no-open --quiet --json | jq -r .metadata.id)

cat > hello-flow.yaml <<'EOF'
appId: com.apple.Preferences
---
- launchApp
- assertVisible: General
- takeScreenshot: settings-check
EOF

lim ios maestro --id "$ID" test hello-flow.yaml

All three steps reporting COMPLETED means Maestro, the runner, and the remote wiring all work; anything failing after this point is about the app or the flow, not the setup.

Run a flow

lim ios maestro test flow.yaml
lim ios maestro test flows/
lim ios maestro --id <ios-id> test flow.yaml

Without --id this targets the most recently created iOS instance in the current workspace (workspaces follow the git repo or worktree you run from); pass --id <ios-id> (before test) in scripts, agents, or when running from a different directory. The first run on an instance takes a few extra seconds to launch the runner (plus the install when it wasn't preinstalled); later runs skip that. Extra Maestro flags go after --:

lim ios maestro -- test flow.yaml --include-tags smoke --test-output-dir artifacts

Do not pass --platform, --device, --udid, --no-reinstall-driver, or --driver-host-port; lim sets those itself and rejects duplicates. Real Maestro exit codes and reports are preserved, so CI wiring works as with local Maestro.

Instance setup

Any running iOS instance works; the runner is installed on first use. Creating the instance with the runner preinstalled skips that step:

lim ios create --install-asset appstore/maestro-ios-runner-2.5.1.tar.gz --no-open

--no-open skips opening the stream URL in a browser (important on headless and CI machines). The runner asset name above is the only published one and it is version-agnostic: the same runner serves Maestro 2.5.x through 2.7.x, so do not look for an asset matching your Maestro version.

Install the app under test as usual (lim ios create --install app.ipa, lim ios install-app, or a build skill), then reference its bundle id via appId: in the flow. For Expo Go testing, also preinstall appstore/Expo-Go-54.0.6.tar.gz and open the project URL with openLink (env vars must be prefixed MAESTRO_ to be visible in flows):

MAESTRO_EXPO_URL='exp://<tunnel-host>' lim ios maestro test flow.yaml

Expo dev-client builds

Expo Go is the quickest path, but a dev-client build works too. launchApp lands on the dev launcher rather than your app, so open the dev-client URL instead: - stopApp followed by - openLink: <scheme>://expo-development-client/?url=<url-encoded-metro-url>. Use limrun-expo-development for building the dev client, starting Metro, and deriving that URL.

Flow gotchas on Limrun

• startRecording/stopRecording YAML commands are not supported (the simulator is remote). Record around the run instead: lim ios record start --id <ios-id> returns immediately (recording happens on the instance), and after the flow lim ios record stop --id <ios-id> -o video.mp4 downloads the video to the local path.
• takeScreenshot works and saves the PNG locally into the working directory (or --test-output-dir), like stock Maestro.
• addMedia and flow commands that reference local simulator file paths are not supported.
• HTTP calls from runScript/evalScript must use https:// URLs. Plain http:// calls are refused (except to the driver itself), because Maestro's plain-HTTP traffic is routed through a local bridge that only forwards to the remote simulator.
• When a flow re-runs against an app that is already open (for example Expo Go), start it with - stopApp before openLink/launchApp; deep links can be dropped by an app that is mid-foreground, and stale screens fail early assertions.
• Fleet variance: anchor assertions on stable accessibility identifiers and text, not on timing. Use extendedWaitUntil with a generous timeout for first app load.
• Text selectors match the element's accessibility label, and on iOS a label often folds in sibling content (icon names, adjacent text) or non-breaking spaces. Read the exact label with lim ios element-tree before writing the selector instead of guessing from what the screen shows.

Validation signals

• Running maestro <version> against <ios-id>... then Running on Limrun iPhone - iOS ...: the driver is connected end to end.
• Launching the Maestro runner...: first use on this instance. Installing the Maestro runner... additionally appears only when the instance was created without the runner asset. Subsequent runs skip both.
• Maestro itself prints several JDK WARNING lines (reflection, native access) on every run; they are benign upstream noise, not Limrun errors.
• Flow failures print Maestro's own debug output directory with screenshots and the UI hierarchy; lim ios element-tree --id <ios-id> shows the live screen when debugging selectors.

Cleanup

Delete the instance when done: lim ios delete <ios-id> (--id is not valid for delete). The wiring lim ios maestro starts is torn down when the command exits.