{"id":1651,"date":"2026-10-26T12:23:58","date_gmt":"2026-10-26T12:23:58","guid":{"rendered":"https:\/\/razvanvancea.ro\/blog\/?p=1651"},"modified":"2026-10-26T12:30:57","modified_gmt":"2026-10-26T12:30:57","slug":"how-to-pass-additional-arguments-to-an-npm-script","status":"publish","type":"post","link":"https:\/\/razvanvancea.ro\/blog\/2026\/10\/26\/how-to-pass-additional-arguments-to-an-npm-script\/","title":{"rendered":"How to Pass Additional Arguments to an npm Script"},"content":{"rendered":"
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When working with npm scripts, you might occasionally need to pass additional command-line arguments without modifying your package.json<\/code>.<\/p>

Luckily, npm provides a simple way to do this using the --<\/code> separator.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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The Problem<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Let’s say you have the following script defined in your package.json<\/code>:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\"npm-flag\"\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Running npm run test<\/code><\/strong> executes:<\/p>

npx playwright test<\/code><\/pre>
But what if you want to run your Playwright tests in headed mode<\/strong>, so you can actually see the browser while the tests execute?

You might try ‘npm run test --headed' , however, <\/code>npm doesn’t reliably forward arguments like --headed<\/code> directly to the underlying script.<\/p>
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The Solution: Use --<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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To pass additional arguments to an npm script, simply add --<\/code> before your arguments:<\/p>
npm run test -- --headed<\/strong><\/code><\/strong><\/pre>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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The --<\/code> separator tells npm to stop interpreting subsequent arguments and pass them directly to the script being executed.<\/p>
Effectively, the command becomes:<\/p>
npx playwright test --headed<\/code><\/pre>
That’s it! No changes to your package.json<\/code> are necessary.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Final thoughts<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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The next time you need to customize the behavior of an npm script, remember this simple pattern:<\/p>
npm run <script-name> -- <additional-arguments><\/code><\/pre>
It’s a small trick, but it makes npm scripts much more flexible and saves you from creating multiple scripts for minor command variations.<\/p>
One separator, unlimited possibilities.<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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Enjoyed this article?
I share more practical automation tips on\u00a0YouTube<\/strong><\/a>\u00a0and\u00a0LinkedIn<\/strong><\/a>.<\/p>
Need structured guidance instead of learning alone?<\/strong>
I offer\u00a01-on-1 mentoring<\/strong>\u00a0– learn more \u2192\u00a0HERE<\/a><\/strong><\/p>
Or email me at\u00a0iamqarv [at] gmail [dot] com<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"
When working with npm scripts, you might occasionally need to pass additional command-line arguments without…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1],"tags":[],"class_list":["post-1651","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t