rule_md047.md

Rule - MD047

Aliases
md047
single-trailing-newline

Summary

Each file should end with a single newline character.

Reasoning

Various parsers and operating system calls have trouble with files that do not end with at least one newline character on its own. It is common on any POSIX operating systems to mandate that each text file be terminated with a single newline character. To make the Markdown documents compatible with these various systems, it just makes sense to end documents with a newline character.

Examples

Failure Scenarios

This rule triggers when the document does not end with a single newline character.

# Heading

This file ends without a newline.

This includes triggering on a final line that contains a newline character followed by one or more whitespace characters. To properly illustrate this, the space characters at the end of the following example have been replaced with the string {space} to make those space characters visible.

# Heading

This file ends with a newline and two space characters.
{space}{space}  

Correct Scenarios

This rule does not trigger when the document does end with a single newline character.

# Heading

This file ends with a newline.

In most editors, if the current file ends with a single newline character, it will appear to be a line with nothing on it. The difficulty with using this as the visual indicator is that most editors do not display a document ending in a newline character any differently than a document ending with a newline characters and one or more whitespace characters.

Configuration

Prefixes
plugins.md047.
plugins.single-trailing-newline.

Value Name	Type	Default	Description
enabled	boolean	True	Whether the plugin rule is enabled by default.

Origination of Rule

This rule is largely inspired by the MarkdownLint rule MD047. and various blogs and answers such as this answer.