hubcap waitfn

Wait for a JavaScript expression to return a truthy value.

When to use

Use waitfn to block until a JavaScript expression evaluates to a truthy value. Use for complex conditions not covered by wait or waittext.

Usage

hubcap waitfn <expression> [--timeout <duration>]

Arguments

Argument	Type	Required	Description
expression	string	Yes	JavaScript expression to evaluate until truthy

Flags

Flag	Type	Default	Description
—timeout	duration	30s	Maximum wait time

Output

Field	Type	Description
completed	bool	Whether the expression returned truthy
expression	string	The expression that was evaluated

{"completed":true,"expression":"window.appReady === true"}

Errors

Condition	Exit code	Stderr
Missing expression argument	1	usage: hubcap waitfn <expression> [--timeout <duration>]
Chrome not connected	2	error: connecting to Chrome: ...
Expression not truthy within timeout	3	error: timeout

Examples

Wait for an app-level ready flag:

hubcap waitfn 'window.appReady === true'

Wait for a specific array length:

hubcap waitfn 'document.querySelectorAll(".item").length >= 10' --timeout 20s

Navigate and wait for a custom condition (chaining):

hubcap goto --wait https://example.com && hubcap waitfn 'window.dataLoaded'

See also

• wait - Wait for an element by CSS selector
• waittext - Wait for text content to appear on the page
• eval - Evaluate a JavaScript expression
• waitgone - Wait for an element to be removed from the DOM