Assertions

Complete reference of expect(locator) and expect(page) - every LocatorAssertions and PageAssertions matcher, how each one compares, the retry schedule, negation and failure messages.

expect(page.getByRole("heading")).toHaveText("Welcome back")
expect(page.locator("li.todo")).toHaveCount(3)
expect(page.getByText("Loading")).not.toBeVisible()
expect(page).toHaveURL(Regex("/dashboard$"))

Function	Returns
`fun expect(locator: Locator): LocatorAssertions`	Web-first assertions on a locator.
`fun expect(page: Page): PageAssertions`	Web-first assertions on a page.

Both are top-level, non-suspending functions in com.bernaferrari.kmpwright.core. Every matcher is suspend, takes a trailing timeoutMs: Long? = null (null uses TimeoutConfig.waitForSelector of the page's browser), and returns Unit. For a guided introduction see the Assertions guide. Source: Expect.kt.

Retry behavior

The condition is evaluated immediately, then after 20, 50, 100 and 100 ms, then every 250 ms.
A condition that throws KmpwrightException (for example a strict-mode violation or "is not a checkbox") counts as not holding and is retried. Other exceptions propagate.
After the timeout, the matcher throws KmpwrightAssertionError, a Kotlin AssertionError (not a KmpwrightException), so test runners report a failed assertion. Its cause is the last KmpwrightException, if any. Waits that are not assertions (waitFor, waitForURL…) keep throwing KmpwrightTimeoutException.
The timeout is checked between attempts, so one slow attempt can overrun it.

Failure message format:

Expected Locator(#status) to have text "Saved", but it did not happen within 30000ms (last error: …)
Expected page not to have URL "https://example.com/login", but it did not happen within 5000ms

Negation

not is a property on both classes that returns the same assertions with the expectation inverted:

expect(page.locator(".spinner")).not.toBeVisible()
expect(page).not.toHaveURL(Regex("/login"))

A negated matcher holds when the condition is false. A condition that throws satisfies neither the plain nor the negated form.

`LocatorAssertions`

Text comparisons normalize whitespace: runs of whitespace become one space and the result is trimmed. Text and emptiness matchers never pass on a missing element (so .not.toHaveText("x") keeps failing until an element exists).

Matcher	Holds when
`toBeVisible(timeoutMs: Long? = null)`	`locator.isVisible()` is true.
`toBeHidden(timeoutMs: Long? = null)`	`locator.isHidden()` is true (missing or not visible).
`toBeAttached(timeoutMs: Long? = null)`	`locator.count() > 0`.
`toBeEnabled(timeoutMs: Long? = null)`	`locator.isEnabled()`.
`toBeDisabled(timeoutMs: Long? = null)`	`locator.isDisabled()`.
`toBeChecked(timeoutMs: Long? = null)`	`locator.isChecked()`.
`toBeFocused(timeoutMs: Long? = null)`	`locator.isFocused()`.
`toBeEditable(timeoutMs: Long? = null)`	`locator.isEditable()` (enabled and not read-only).
`toBeEmpty(timeoutMs: Long? = null)`	An element with a `value` (except `<button>`) has `value == ""`; any other element has blank `textContent`. A missing element is not empty.
`toHaveText(text: String, timeoutMs: Long? = null)`	Normalized `innerText` equals normalized `text`.
`toHaveText(text: Regex, timeoutMs: Long? = null)`	`text` is found in the normalized `innerText` (`containsMatchIn`).
`toContainText(text: String, timeoutMs: Long? = null)`	Normalized `innerText` contains normalized `text`.
`toContainText(text: Regex, timeoutMs: Long? = null)`	`text` is found in the normalized `innerText`.
`toHaveValue(value: String, timeoutMs: Long? = null)`	`locator.inputValue() == value` (exact, not normalized).
`toHaveValue(value: Regex, timeoutMs: Long? = null)`	`value` is found in `inputValue()` (null treated as `""`).
`toHaveAttribute(name: String, timeoutMs: Long? = null)`	The attribute exists. Use `.not.toHaveAttribute(name)` for absence.
`toHaveAttribute(name: String, value: String, timeoutMs: Long? = null)`	The attribute equals `value` exactly.
`toHaveAttribute(name: String, value: Regex, timeoutMs: Long? = null)`	The attribute exists and `value` is found in it.
`toHaveClass(className: String, timeoutMs: Long? = null)`	The normalized `class` attribute equals the normalized `className` (the whole attribute, in order).
`toHaveClass(className: Regex, timeoutMs: Long? = null)`	`className` is found in the `class` attribute. Use `Regex("\\bactive\\b")` to test for one class.
`toHaveCount(count: Int, timeoutMs: Long? = null)`	`locator.count() == count`.

Differences from Playwright:

toHaveText and toContainText compare against innerText (rendered text), not textContent, and take one string, not an array.
There are no options objects (ignoreCase, useInnerText); use a Regex with RegexOption.IGNORE_CASE for case-insensitive checks.
Matchers that read a single element are subject to strict mode: a locator matching several elements keeps failing with a strict-mode violation until the timeout. Use first(), nth() or toHaveCount.

`PageAssertions`

Matcher	Holds when
`toHaveURL(url: String, timeoutMs: Long? = null)`	`location.href` matches `url` with Playwright's URL glob rules (see Page): a string without glob characters must equal the URL; ``, `*` and `{a,b}` are globs.
`toHaveURL(url: Regex, timeoutMs: Long? = null)`	`url` is found in `location.href`.
`toHaveURL(timeoutMs: Long? = null, predicate: (String) -> Boolean)`	`predicate` accepts `location.href`.
`toHaveTitle(title: String, timeoutMs: Long? = null)`	Normalized `document.title` equals normalized `title`.
`toHaveTitle(title: Regex, timeoutMs: Long? = null)`	`title` is found in `document.title`.

The URL and title are read from the live document on every attempt (falling back to page.url / page.title when evaluation fails). Relative URL patterns are not resolved, because KMPwright has no baseURL.

Assertions guide
Locator for the underlying state queries.
Errors

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Retry behavior

Negation

`LocatorAssertions`

`PageAssertions`

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