fix-unnatural-line-breaks

A skill for eliminating a specific bad habit: inserting a newline mid-sentence just to keep the line under some fixed column width. Line breaks should only appear at meaningful boundaries — paragraph breaks, list item boundaries, and around headings.

Core principle

Don't break a sentence or paragraph until it actually ends. Even when a line "feels" long, keep writing on the same line until the next meaningful boundary (end of paragraph, end of a list item, before/after a heading, before/after a code block). Let the editor, browser, or terminal handle visual wrapping (soft wrap) — the source itself should not contain a hard-coded newline chosen purely for line length.

This applies equally to English and Japanese, but the damage is arguably worse in Japanese. Japanese has no spaces between words, so an arbitrary line break doesn't look grammatically broken the way it might in English — yet breaking right after a comma, particle, or in the middle of a phrase still disrupts the reading rhythm and makes it easy to misread where a clause actually ends.

The target is both prose documentation (Markdown, README files) and code comments, docstrings, and JSDoc. For documentation, most Markdown renderers collapse a single newline inside a paragraph into a single space, so the rendered output often looks fine either way — but the raw source still suffers: it's harder to read as source, diffs get needlessly large when a whole paragraph reflows, and there are places where the raw newline is shown as-is (commit messages, terminals, an editor's hover tooltip for a code comment). For code comments there is no renderer to save you — the line break is shown exactly as written, so the harm is direct and immediate.

Do

• When writing new prose (documentation or comments) from scratch, write one paragraph per line (or one sentence per line) from the start, and never wrap at an arbitrary column width.
• When reviewing or fixing existing prose, use the criteria in references/detection.md to find breaks that cut a sentence in the middle, then fix them following references/rules.md.
• To fix one, simply remove the line break and join the two lines: insert a single space for English, and nothing (no space) for Japanese. See references/examples.md for concrete cases where the right join is ambiguous.
• It's fine — expected, even — for the fixed line to become very long. The only thing that should trigger a new line break is a structural boundary (paragraph, list item, heading, code block), never a character count.
• In a comment block, if two paragraphs need a visible separator, use an unmarked blank line (no ///#/*) or no separator at all — never a bare comment marker with nothing after it. Nobody writes a lone // by hand; see references/rules.md.