name: trailing-whitespace default: true advisory: false fix: true since: 0.1.0

trailing-whitespace

Trailing whitespace at end of line.

What it does

Flags lines that end with one or more trailing space or tab characters. The exception is the CommonMark hard-break convention: exactly two trailing spaces followed by a newline introduces a <br> inside a paragraph, and that case is left alone.

Why

Trailing whitespace is invisible noise that survives copy-paste, complicates diffs (one-byte changes that touch every line), and frequently triggers spurious changes when collaborators have different editor settings. The autofix strips the trailing run while preserving the two-space hard break form.

Example (bad)

A paragraph.···
Another line.·

(· represents a stray trailing space.)

Example (good)

A paragraph.
Another line.

Configuration

  • Disable inline: <!-- mdwright: allow trailing-whitespace -->.
  • Disable in config: [lint] ignore = ["trailing-whitespace"].
  • Severity: non-advisory. Safe autofix available.

References