ButtonTypeExplicit [rule] v1.0.0

Every <button> element MUST declare an explicit type attribute (button, submit, or reset). The HTML default is submit, which inside a <form> causes any unrelated button (e.g. an icon toggle) to submit the form on click — a common, hard-to-debug bug.

Checks

• @community/check-button-type-explicit

Applies To

@community/type-html-artifact

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Severity

high

Severity Combination

<button> inside a form without type=  → BLOCK
<button> outside a form without type= → WARN
<button type='...'>                   → PASS

Failure Mode

An icon-toggle button inside a form silently submits the form; users lose unsaved state; double-submission charges customers twice. The bug is invisible until production traffic hits the right page.

Remediation

• Add type='button' to every button that is NOT the form's submit action.
• Add type='submit' to the one button intended to submit (and prefer placing only one).
• Add a lint rule (react/button-has-type for React, @angular-eslint/template/button-has-type for Angular) to enforce in CI.
• Wrap legacy buttons during migration: const SafeButton = (p) => <button type='button' {...p} />.

Exceptions

• • Case: Submit-only inside a single-field form
  • Allowed When: A form has exactly one button whose purpose is submit; defaulting still works — but adding the attr costs nothing.

ButtonTypeExplicit [rule] v1.0.0

Every <button> element MUST declare an explicit type attribute (button, submit, or reset). The HTML default is submit, which inside a <form> causes any unrelated button (e.g. an icon toggle) to submit the form on click — a common, hard-to-debug bug.

Checks

• @community/check-button-type-explicit

Applies To

@community/type-html-artifact

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Severity

high

Severity Combination

<button> inside a form without type=  → BLOCK
<button> outside a form without type= → WARN
<button type='...'>                   → PASS

Failure Mode

An icon-toggle button inside a form silently submits the form; users lose unsaved state; double-submission charges customers twice. The bug is invisible until production traffic hits the right page.

Remediation

• Add type='button' to every button that is NOT the form's submit action.
• Add type='submit' to the one button intended to submit (and prefer placing only one).
• Add a lint rule (react/button-has-type for React, @angular-eslint/template/button-has-type for Angular) to enforce in CI.
• Wrap legacy buttons during migration: const SafeButton = (p) => <button type='button' {...p} />.

Exceptions

• • Case: Submit-only inside a single-field form
  • Allowed When: A form has exactly one button whose purpose is submit; defaulting still works — but adding the attr costs nothing.

Relations

related: [@community/rule-form-validation-inline, @community/fact-error-prevention, @community/rule-aria-label-required] see-also: [@community/check-button-type-explicit] validates-with: [@community/fact-error-prevention]

Applies To

@community/type-html-artifact

Meta

• License: Apache-2.0
• License Provenance: package-authorship-claim

Severity

high

Validates With

• @community/fact-error-prevention

Severity Combination

<button> inside a form without type=  → BLOCK
<button> outside a form without type= → WARN
<button type='...'>                   → PASS

Failure Mode

An icon-toggle button inside a form silently submits the form; users lose unsaved state; double-submission charges customers twice. The bug is invisible until production traffic hits the right page.

Remediation

• Add type='button' to every button that is NOT the form's submit action.
• Add type='submit' to the one button intended to submit (and prefer placing only one).
• Add a lint rule (react/button-has-type for React, @angular-eslint/template/button-has-type for Angular) to enforce in CI.
• Wrap legacy buttons during migration: const SafeButton = (p) => <button type='button' {...p} />.

Exceptions

• • Case: Submit-only inside a single-field form
  • Allowed When: A form has exactly one button whose purpose is submit; defaulting still works — but adding the attr costs nothing.

See Also

• @community/check-button-type-explicit