hubcap run

Execute JavaScript from a file in the page context.

When to use

Execute JavaScript from a file in the page context. The file contents are read and evaluated as a single expression. Use eval for inline expressions instead of loading a file.

Usage

hubcap run <file>

Arguments

Argument	Type	Required	Description
`file`	string	Yes	Path to a `.js` file to execute

Flags

None.

Output

Field	Type	Description
`file`	string	Path to the executed file
`value`	any	The returned value from the script

{"file":"script.js","value":42}

Errors

Condition	Exit code	Stderr
File not found	1	`error reading file: ...`
JavaScript evaluation error	1	`error: JS exception: <message>`
Chrome not connected	2	`error: connecting to Chrome: ...`
Timeout	3	`error: timeout`

Examples

Run a script:

hubcap run setup.js

Run a script and extract the result with jq:

hubcap run check.js | jq '.value'

Use a script that returns page data, then pipe into further processing:

hubcap run scrape.js | jq -r '.value[]' | sort -u > links.txt