grafana/k6 · error

non-multiple file input can only accept single file

Error message

non-multiple file input can only accept single file

What it means

This message is produced by errorFromDOMError in k6's browser module (element_handle.go:1896-1916), which translates the injected-script error 'error:notmultiplefileinput' into a readable error. It is thrown by setInputFiles when more than one file is supplied to an <input type="file"> element that does not have the 'multiple' attribute. The DOM input can only hold a single file, so the call is rejected before any upload happens.

Source

Thrown at internal/js/modules/k6/browser/common/element_handle.go:1915

		"error:notelement":             "node is not an element",
		"error:nothtmlelement":         "not an HTMLElement",
		"error:notfillableelement":     "element is not an <input>, <textarea> or [contenteditable] element",
		"error:notfillableinputtype":   "input of this type cannot be filled",
		"error:notfillablenumberinput": "cannot type text into input[type=number]",
		"error:notvaliddate":           "malformed value",
		"error:notinput":               "node is not an HTMLInputElement",
		"error:notfile":                "node is not an input[type=file] element",
		"error:hasnovalue":             "node is not an HTMLInputElement or HTMLTextAreaElement or HTMLSelectElement",
		"error:notselect":              "element is not a <select> element",
		"error:notcheckbox":            "not a checkbox or radio button",
		"error:notmultiplefileinput":   "non-multiple file input can only accept single file",
		"error:strictmodeviolation":    "strict mode violation, multiple elements returned for selector query",
		"error:notqueryablenode":       "node is not queryable",
		"error:nthnocapture":           "can't query n-th element in a chained selector with capture",
		"error:intercept":              "another element is intercepting with pointer action",
	}
	if err, ok := errs[serr]; ok {
		return errors.New(err)
	}

	return errors.New(serr)
}

View on GitHub (pinned to 01ffac6f24)

Solutions

1. Pass a single file payload object (not an array) to the non-multiple input: page.setInputFiles(sel, {name, mimeType, data})
2. If multiple files are intended, verify the selector targets the actual <input type="file" multiple> element and fix the selector
3. Branch in the script: read the input's multiple attribute via page.evaluate and send one file or many accordingly
4. If the WuT is expected to accept many files, fix the page markup rather than the test

Example fix

// before
await page.setInputFiles('input[type=file]', [fileA, fileB]);

// after (single-file input)
await page.setInputFiles('input[type=file]', fileA);

// Inspect the input before uploading
const isMultiple = await page.$eval(
  'input[type=file]',
  el => el.hasAttribute('multiple')
);
const files = isMultiple ? [fileA, fileB] : fileA;
await page.setInputFiles('input[type=file]', files);

try {
  await handle.setInputFiles(files);
} catch (e) {
  if (/single file/.test(e.message)) {
    await handle.setInputFiles(files[0]); // retry with one file
  } else throw e;
}

When it happens

Trigger: Calling handle.setInputFiles([...]) or page.setInputFiles(selector, [...]) with an array of two or more file payloads while the matched element is <input type="file"> without the multiple attribute. Passing a single-element array is fine; two or more payloads triggers it.

Common situations: Test scripts written against multi-upload forms reused on single-upload pages (avatar/resume upload); test data generators that always emit arrays; the WuT markup changed and dropped the multiple attribute.

Related errors

• parsing setInputFiles parameter: %w
• node is not queryable
• parsing setInputFiles options: %w
• parsing setInputFiles parameter: %w
• focusing on element: %w

AI-assisted analysis of grafana/k6@01ffac6f24 (2026-08-18). Data as JSON: /api/errors/5b304741ced48271. Report an issue: GitHub.