An application under test for Mobium.
A React Native app whose only job is to be driven. Every screen is a positive control for something that can go wrong when a tool automates a mobile app: a check that only ever sees the good case cannot tell you it would notice the bad one, so each screen can produce both.
Mobium's end-to-end checks drive it — docs/checks/mobium-app.sh, login.sh,
dialogs.sh, gestures.sh, autowait.sh and others in the main repository.
Real third-party apps are better evidence, and Mobium keeps using them: they break rules a fixture never thought to break. This app does not replace them. It exists for cases no shipped app can provide on demand — two live WebViews in one app, a login with a known account, a dialog with three buttons, a screen that never stops moving.
On iOS there is a second reason, and it is why the app had to be written
rather than downloaded: a WKWebView is invisible to Remote Web Inspector
unless the app sets isInspectable (iOS 16.4 and later), and that cannot be
forced from outside. An app that does not opt in is unreachable, so the app
under test opts in itself — webviewDebuggingEnabled on every WebView.
| Screen | Main test IDs | What it is a control for |
|---|---|---|
| WebViews | webviewBtn, wideBtn, dualBtn, webstorageBtn, framesBtn |
Web pages inside the app. Plain page (webview): a WebView whose frame equals its content. Wide viewport (wideWebview): a page laid out at 1200 CSS px, so the visual and layout viewports differ. Two WebViews (webviewTop, webviewBottom): two inspectable pages alive at once. Actionability (actionWebview; data-testid wSlide, wReplay, wDisabled, wArm, wEnabling, wAria, wFull, wHalf, wPass, wPlain, wBelow; actState()): the Obstruction Demo's web counterpart — a target sliding in, disabled, disabled for a moment, aria-disabled, fully covered, center covered, under pointer-events: none (the negative control), under a plain div, and below the fold, each cover recording its own taps so actState() says what a tap really reached. Web form (formWebview; data-testid fText, fEmail, fArea, fReadonly, fAriaReadonly, fDisabled, fPassword, fCheck; formState(), passwordIs()): fields to type into — plain (mirrored live, so a tool can tell the page heard the change), email, multi-line — ones that must refuse text — read-only, aria-readonly, disabled — a password field reported only by length, and a checkbox, which is not a text field. Web storage (storageWebview, storageBox, saveVisit; storageState()): a page loaded with the base URL https://mobiumapp.test/, so it has an origin — and so cookies and web storage — while every other page here is inline with none; .test is reserved for testing and never resolves, so nothing leaves the device. It shows what it holds, read again every second, and Save a visit writes a cookie, a localStorage and a sessionStorage entry. Frames (framesWebview, frameOutcome, frameTyped): a same-origin frame, one nested inside it and a cross-origin one, each reporting which frame a tap reached; the cross-origin one also holds a text field (crossField), as a payment provider's card field sits in a frame of its own, whose contents frameTyped shows |
| Login Demo | username, password, loginBtn, loginError, welcomeText, logoutBtn |
Mobile automation's hello world. Labeled fields validated on leaving and on submit, a one-second sign-in (a test must wait, not sleep), one message for a wrong password and an unknown user alike, and a screen reachable only by logging in. The password field is secureTextEntry, so a tool must never print its value |
| OTP Demo | otpSend, otpShowCode, otpCodeShown, otpExpires, otpOutcome, otpBox0–otpBox5, otpEntered, otpVerifyBoxes, otpField, otpVerifyField |
A one-time code after the password. Six single-digit boxes that move focus on every digit and back on delete — typing the whole code into the first box, or losing a keystroke while focus moves, gets it wrong, and otpEntered shows exactly what they hold — beside one oneTimeCode field for comparison. The code is random and arrives as a local notification, read from the shade, or on screen with the switch where the shade cannot be read. It expires in 60 seconds (otpExpires), can be resent after 20 (the button is disabled until then), is single-use, and three wrong codes lock the form; otpOutcome says which, and stays near the top so it is on screen while the keyboard is up |
| Form Demo | notifyCheck, termsCheck, planFree/planPro/planTeam, darkSwitch, formState, readOnlyField |
Controls with a state rather than only a label: checkboxes and radios as Pressable with accessibilityRole and accessibilityState — React Native has neither built in — a native Switch, and a read-only field. The Dark mode switch themes the whole app, so its effect can be checked in the hierarchy, in formState and in the screen's pixels |
| Pager Demo | pager, card1..card8, pagerTapped |
A horizontal carousel. Nothing in a hierarchy says which way a container scrolls, so this is what a horizontal scroll is pointed at |
| Feed Demo | feed, feedRow1..feedRow60, feedLoading, feedEnd, feedState, feedFast, feedSlow |
A list that grows as it is scrolled, as a timeline does: twenty rows a page, the next page loaded after a delay — 2.5 seconds, or 0.3 with Load in 0.3s — with a spinner (feedLoading) below the last row while it loads. The swipe that reaches the end of a page moves nothing, because the next rows are not there yet, so a tool that takes that for the end of the list stops early. The feed truly ends after three pages under feedEnd, the negative control, and feedState says how many rows the app holds and whether it is loading |
| Slider Demo | volumeSlider, balanceSlider, sliderState |
Controls whose state is a position. Volume runs 0 to 100 in steps of 10, so a move that lands a step past its target shows as the wrong number; Balance is continuous from 0 to 1. Both are labeled, and neither belongs to the device, so moving them changes nothing a person owns, as a Settings slider would. sliderState says what the app holds and how many changes it received. Uses @react-native-community/slider: a native SeekBar on Android, which Mobium drives; on iOS a UISlider that reports itself to accessibility as a plain view, with no Adjustable trait and no value, so no tool outside the app can call it a slider. Level (levelSlider) is the same slider made accessible as a well-built app ships it — the adjustable role, a value with its range, increment and decrement — so it reports the Adjustable trait and a value; and Range is a web page's <input type="range"> (webRange, 0 to 100 in steps of 10, its value in webRangeOut) in an inspectable WebView. Below it, two two-thumb sliders as pages build them: Price (priceMin, priceMax, 0 to 1000 in fifties, priceOut), two ranges on one track whose minimum the page keeps at or below its maximum, giving way by which thumb has focus; and Hours (hoursStart, hoursEnd, 0 to 24, hoursOut), two ARIA sliders on a drawn track, moved by a finger or the arrow keys |
| Busy Demo | busyRefresh, busyQuiet, busyAlert, busyTwice, busyPoll, busyCrash, busyRowA–busyRowC, busySpinner, busyOutcome |
Work that finishes after the screen looks finished. Both buttons start the same 0.4 to 1.6 seconds of work, then bring a new generation of rows: Refresh shows a spinner in place of the rows meanwhile, Refresh quietly leaves the old rows up and tappable. A row says in busyOutcome whether the one tapped was current — the latest generation, with no work pending — or stale. The control for Mobium's gray box: the app tells its graybox module (modules/graybox) when work starts and when the new rows are rendered, and the module writes it to the device log when the app was launched with -MobiumGrayBox YES on iOS or with the intent extra MobiumGrayBox=true on Android. The edge controls are each a way a gray box could wait wrongly: Refresh from an alert starts the work from a button in the alert's own window, Refresh twice runs two at once, Keep polling never finishes, and Crash during a refresh dies holding the work |
| Audio Demo | audioTone, audioSequence, audioLoop, audioSilent, audioAlarm, audioStop, audioState |
Known sounds, so a tool that says what an app played can be shown hearing it. Generated sine tones at a quarter of full volume: 440 Hz for 2 s; 440 Hz, a second of silence, then 880 Hz, for when sound starts and stops and which pitch it was; 440 Hz until stopped (a minute at most); and 660 Hz as an alarm, a usage only Android keeps. Silence is the negative control: a player that is started and plays 2 s of zeros, which the platform reports exactly as it reports the tone. audioState says what was played and whether it finished or was stopped. Uses the app's own tone module (AudioTrack on Android, AVAudioEngine on iOS) |
| Hooks (any screen) | hookToast |
Functions Mobium's gray box calls by name with mobium hook, registered at the app's root so they work on any screen: raiseToast shows its message in a toast the app draws (on Android a system toast too), screen answers the screen showing, signIn signs in as the name given without the Login Demo's form. Calls arrive only in a gray-box launch, through a field the library adds then (mobium-mailbox) |
| Interruption Demo | keptDraft, lostDraft, askPermission, rebuildCount |
An interruption, and what the app has left afterwards. The button raises a real system permission dialog; of the two fields, the first keeps what was typed and the second is rebuilt empty, the way an app loses a half-written form. The second is the positive control, so "nothing was lost" can be told from a check that cannot see loss |
| Dialog Demo | dialogOutcome, oneButtonBtn, twoButtonBtn, threeButtonBtn, lateAlertBtn, actionSheetBtn, promptBtn, shareBtn, locationBtn, notificationsBtn, cameraBtn, trackingBtn, pasteBtn, coveredBtn |
Every kind of dialog the app can raise, each writing what the app received to one line: alerts with one, two and three buttons, one that arrives late, an iOS action sheet, a prompt with a text field (iOS only), the share sheet, location, camera, notification and tracking permission, Allow Paste on iOS, a login-shaped form for Save Password, and a button the keyboard covers |
| Table Demo | tableOutcome, table, tableRow1–tableRow30, rowMore, rowDelete, rowStarred |
Thirty rows, Item 1 to Item 30, each with a More and a Delete that share their test IDs across rows, as a real list's cells do, so only the row says which is which: the control for a locator scoped to a row. Item 8 has no More, so a scope must not borrow the next row's; Items 1 to 3 have a Starred switch; "Item 1" is also a part of Items 10 to 19. The line says what was pressed and in which row |
| Obstruction Demo | obstructionOutcome, fullTarget/fullCover, halfTarget/halfCover, edgeTarget/edgeCover, passTarget/passCover, plainTarget/plainCover, hiddenTarget, scrimTarget/scrimCover, toastBtn, toastTarget/toastCover |
Targets the app has drawn something over, the kind a system dialog or the keyboard is not. Each cover is itself pressable, so obstructionOutcome names what a tap really touched: a cover over all of the target, over its center, over its edge only, a view with pointerEvents="none" (the negative control — the tap reaches the target), a plain view that swallows the tap, a pressable hidden from accessibility, a translucent scrim, and a toast that covers its button for 1.5 seconds |
| Accessibility Demo | a11yState, a11yRefresh, a11ySample |
What the platform tells the app about its accessibility settings, on one line a check can read: Bold Text, Increase Contrast, Grayscale, Invert Colors, Reduce Motion, Reduce Transparency, VoiceOver, and the text scale, with a count of change events. Each value is updated live from the platform's change event and read afresh on Refresh, so a setting changed while the app runs can be told from one seen after a relaunch — the half of a setting written from outside that has to reach the app before it is worth anything |
| Layout Demo | tinyTarget, narrowTarget, layoutWidth |
The positive control for mobium's layout inspection. tinyTarget is 24dp square, under Android's 48dp touch minimum at every screen size; narrowTarget is an eighth of the window's width, fine on a 411dp phone and too narrow below 384dp. A layout check must report the first everywhere and the second only when the screen shrinks — without them, a run that finds nothing cannot be told from one that sees nothing |
| Location Demo | coords, fixCount |
The observer for a simulated location. iOS can set a position and not read one back, so the app reports what it sees. fixCount counts deliveries, not movement — compare coords to see a route |
| Motion Demo | reduceMotion, honoringTarget, ignoringTarget, motionWebview, celebrateBtn, confettiState |
Targets that move. Two slide in over two seconds; one honors Reduce Motion and the other never does, as the negative control. Confetti is a burst over the screen that takes no touches, so a button beside it stays tappable — and a switch exposes the pieces as targets that never hold still |
| Crash Demo | logLineBtn, loggedCount, crashJsBtn |
Device logs and crash reports. One button writes a numbered line to the device log; the other throws an unhandled JavaScript error, which a Release build treats as fatal. On a real iPhone, where nothing outside an app can crash it, this is the only way to produce a crash on demand |
| Storage Demo | storedCount, storedFile, saveOneMoreBtn |
Clearing an app's data. A count kept in a file survives a relaunch and reads stored: 0 once the data is cleared, so the app itself reports the outcome |
| Gestures | one screen per gesture | Every touch gesture's witness. Tap and Press (pressTarget, lastGesture), Double Tap (doubleTapWebview), Drag (dragSource, dropZone, lastDrag), Flick and Pan (flickList, flickResult), Pinch and Spread (pinchWebview), Rotate (rotateWebview), and Multi-Touch (holdZone, tapZone, multiResult, multiEvents), which records every raw touch event |
| Files Demo | filesBtn |
A file crossing between a computer and the device, seen from the app. Download the report (saveReportBtn) saves mobium-report.txt where the device keeps downloads — the shared Download folder on Android, through a small native module (modules/downloads) since Expo writes only to the app's private folders; this app's Documents on iOS, which the Files app shows — and savedFile says where, how big and its first line. Upload a file (pickFileBtn) opens the system file picker, and pickedFile says the name, size and first line of what was picked. The observer app_upload and app_download are checked against |
| Biometrics Demo | biometricsBtn, bioHardware, bioEnrolled, bioLevel, bioSignIn, bioPending, bioOutcome, bioAttempts |
A sign-in with a face or a finger, and what the platform answered — the observer app_biometric had none of. What the device offers (bioHardware: face, fingerprint) and whether one is enrolled (bioEnrolled, bioLevel) are read every second, since enrollment changes from outside while the app is on screen. Sign in with biometrics (bioSignIn) asks for biometrics only, with no passcode to fall back to, so a stranger comes back as a failure; bioOutcome says each attempt's answer — success, or the platform's reason (not_enrolled, user_cancel, lockout, authentication_failed) — numbered by bioAttempts, so a new answer can be told from the last, and bioPending says whether a prompt is up and waiting. Face ID's usage string is set, so the app can be signed with a free Apple ID and still ask |
| Battery Demo | batteryBtn |
The battery as this device reports it through the platform's API: a battery drawn to the exact level (batteryGauge, whose label says the level and state), batteryLevel as a percentage, batteryRaw as the platform's 0–1 value, batteryState (unplugged, charging, full, unknown), batteryLowPower, and batteryReads, which counts the reads — every second — so a screen still reading can be told from one that stopped. The observer app_battery had none of: on an emulator adb emu power capacity 42 moves it; a simulator has no battery: it shows No battery, and stops reading |
The lost draft is a deliberate model, not an organic bug. On Android the same symptom comes from the activity being recreated, which the "don't keep activities" developer option forces.
Pages are shipped inline, not fetched, so no check depends on a domain
staying up. Every page's "Learn more" is a real link to
https://github.com/mobiumdev, defined once as LINK_URL; a check asserts the
link's href by asking the page, which needs no network, and following it is
a separate, opt-in assertion.
The Location screen is native, not a WebView: navigator.geolocation
needs a secure context, and the inline pages are served at an about:blank
origin.
flutter/ is a second, smaller app under test, written in
Flutter: Flutter draws its own widgets and publishes a semantics tree, a
hierarchy shape React Native never produces. Mobium's docs/checks/flutter.sh
drives it. Its README has the screen and how to build it.
tv/ is MobiumTV, an app under test for Fire TV, Android TV
and Google TV, driven with a remote: focus, select against touch, a row that
scrolls with focus, a dialog, and media keys. Plain Android, built with
Gradle; its README has the screens and how to install it on a TV.
The Login Demo signs in with mobium / hunter2, and the screen shows
them. Capitals and surrounding spaces in the username are ignored. To see the
errors, leave a field empty, use a username shorter than three characters or
with a space in it, a password shorter than six, or a wrong password.
npm install
# iOS: a simulator, or an iPhone by its UDID
npx expo prebuild --platform ios
npx expo run:ios --configuration Release --device <udid>
# Android: an emulator or a phone
npx expo prebuild --platform android
npx expo run:android --variant releaseRelease rather than debug on purpose: it bundles the JavaScript, so the installed app needs no Metro server and a check script can drive it cold.
The bundle identifier and package are both dev.mobium.mobiumapp.
MIT — see LICENSE.