MD047 - Files Should End with a Single Newline Character
Severity: Warning
Category: Whitespace
Auto-fix: ✓ Available
Rule Description
This rule ensures files end with exactly one newline character. This is a POSIX standard and helps with version control systems.
Why This Rule Exists
Files ending with a newline are important because:
- POSIX standard requires text files to end with a newline
- Git and other VCS show "No newline at end of file" warnings
- Prevents issues when concatenating files
- Ensures consistent file formatting
- Some tools expect the trailing newline
Examples
❌ Incorrect (violates rule)
# Document
Last line without newline```
Or with multiple newlines:
```markdown
# Document
Last line with multiple newlines
✅ Correct
# Document
Last line with single newline
Configuration
This rule has no configuration options.
Automatic Fix
This rule supports automatic fixing with --fix. The fix will:
- Add a newline if the file doesn't end with one
- Remove extra newlines if there are multiple
- Ensure exactly one newline at the end of the file
Apply Fix
# Fix file endings
mdbook-lint lint --fix docs/
# Preview what would be fixed
mdbook-lint lint --fix --dry-run docs/
When to Disable
Consider disabling this rule if:
- You're working with files that intentionally lack final newlines
- Your toolchain doesn't support files with trailing newlines
- You're dealing with generated content that doesn't include newlines
Disable in Config
# .mdbook-lint.toml
disabled_rules = ["MD047"]
Disable for Specific Files
Since this is a file-level rule, you can exclude specific files:
# .mdbook-lint.toml
[[overrides]]
path = "no-newline.md"
disabled_rules = ["MD047"]