Fade a hidden element into view.

jQuery: fadeIn shows a hidden element and calls its completion handler.

JavaScript example.html
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Example</title>
</head>
<body>
<div style="display:none">Message</div><output></output>
<script src="jquery.min.js"></script>
<script>
$('div').fadeIn(20,()=> $('output').text('done'));
</script>
</body>
</html>

Expected output EXAMPLE

The “div” element is visible.

Details

Save as example.html beside jquery.min.js (jQuery 3.5.1). The browser test uses that local library and checks the resulting behavior. fadeIn shows a hidden element and calls its completion handler.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · · Chromium 141.0.7390.37 · libc6 2.39-0ubuntu8.9; Playwright 1.56.0; jQuery 3.5.1

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel
x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale
uid=65534, gid=65534 (unprivileged) / C.UTF-8
Interpreter invocation
Chromium: open example.html; execute the published browser assertions
Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd
Code SHA-256
3c1c6a4cb942f6336be5a5db1d1c260405d86b85ba5534ec11d1bba098f23455
Dependencies
libc6 2.39-0ubuntu8.9; Playwright 1.56.0; jQuery 3.5.1

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

Expected output describes the rendered page. The standard-output record below is the browser test harness receipt; the additional assertions check the result and interactions.

Fade a hidden element into view: browser checks passed.

Exit code: 0. Standard error: empty. Validation: Shape/content assertions. System-dependent values above are one recorded run.

Additional assertions that passed

Checks recorded by the test harness. Where Python assertions are shown, browser cases use Playwright and simulator cases may inspect pin transitions: result.stdout is captured output, work is the temporary directory, and Path is pathlib.Path. The harness also imports json and csv.

await page.wait_for_function('document.querySelector("output").textContent==="done"')
assert await page.locator('div').is_visible()