#expect

Auto-retrying assertions. All polling, actionability checks, and retries run inside the Rust core (ferridriver-expect) — the JavaScript / TypeScript binding is a thin wrapper, so the retry loop never crosses the language boundary.

#Rust matchers (38)

Modifiers on every matcher: .not(), .with_timeout(), .soft(), .with_message(). Page / URL / value matchers accept impl Into<StringOrRegex>, so you can pass either a &str or a regex.

#Page (4)

#Locator — visibility / state (10)

to_be_visible, to_be_hidden, to_be_enabled, to_be_disabled, to_be_checked, to_be_editable, to_be_attached, to_be_empty, to_be_focused, to_be_in_viewport

#Locator — text / value (6)

to_have_text, to_contain_text, to_have_value, to_have_values, to_have_texts, to_contain_texts

#Locator — attributes (9)

to_have_attribute, to_have_class, to_contain_class, to_have_css, to_have_id, to_have_role, to_have_accessible_name, to_have_accessible_description, to_have_accessible_error_message

#Locator — other (5)

to_have_js_property, to_have_count, to_match_snapshot, to_have_screenshot, to_match_aria_snapshot

#Poll / satisfy (4)

• to_equal — polled value equals expected
• to_satisfy — polled value passes a user predicate
• to_pass — run an async closure until it succeeds
• to_pass_with_options — to_pass with custom intervals / timeout

#JavaScript / TypeScript matchers

The expect global is available in run_script, in BDD JS / TS step bodies, and in extensions. It is a thin QuickJS binding (ferridriver-script) over the same ferridriver-expect core, so every matcher delegates to the Rust implementation. String matchers also accept a native RegExp.

expect(value | locator | page | apiResponse | fn) dispatches on the runtime type:

Value (Jest-style): toBe, toEqual, toStrictEqual, toBeNull, toBeUndefined, toBeDefined, toBeTruthy, toBeFalsy, toBeNaN, toBeCloseTo, toBeGreaterThan, toBeGreaterThanOrEqual, toBeLessThan, toBeLessThanOrEqual, toContain, toContainEqual, toHaveLength, toHaveProperty, toMatch, toMatchObject, toBeInstanceOf, toThrow.

Page: toHaveTitle, toHaveURL.

Locator — visibility / state: toBeVisible, toBeHidden, toBeEnabled, toBeDisabled, toBeChecked, toBeEditable, toBeAttached, toBeEmpty.

Locator — text / value / attributes: toHaveText, toContainText, toHaveValue, toHaveCount, toHaveAttribute.

APIResponse: toBeOK.

Poll: expect.poll(fn, { timeout? }).toBe / .toEqual / .toSatisfy.

Asymmetric: expect.any, expect.anything, expect.arrayContaining, expect.objectContaining, expect.stringContaining, expect.stringMatching, expect.closeTo, plus the expect.not.* shorthand.

Modifiers: .not (a getter returning a negated proxy), .soft() (or expect.soft(...)), .withTimeout(ms), and .withMessage(msg).

#Retry cadence

Polling schedule follows Playwright: 100, 250, 500, 1000 ms, then 1000 ms thereafter. The total wait is capped by expectTimeout (default 5000 ms). Polling and actionability checks are implemented in Rust — the JS binding issues a single async call per assertion and the core loop decides when to re-check.