format

Checks for YAML formatting issues in workflow files.

Why This Matters

Consistent formatting:

Improves readability: Easier to review and maintain
Reduces merge conflicts: Consistent style means fewer formatting-only changes
Catches errors early: Some formatting issues can cause YAML parsing problems

What It Detects

Issue	Description
Trailing whitespace	Spaces at the end of lines
Multiple blank lines	More than one consecutive empty line
Line length	Lines exceeding max length (default: 120)
Indentation	Incorrect indentation width or tabs

Example Output

ci.yml:1: (format) Line has trailing whitespace
ci.yml:10: (format) Multiple consecutive blank lines
ci.yml:25: (format) Line exceeds maximum length of 120 characters (got 145)
ci.yml:30: (format) Line uses tabs for indentation; use spaces instead

Auto-fix

Partially supported with --fix:

Issue	Auto-fix
Trailing whitespace	✓
Multiple blank lines	✓
Line length	✗
Indentation	✗

github-ci lint --fix

Line length and indentation issues require manual fixing as they may affect the meaning of the YAML.

Configuration

Configure format settings in .github-ci.yaml:

linters:
  settings:
    format:
      indent-width: 2      # Expected spaces per indent level
      max-line-length: 120 # Maximum line length

indent-width

The expected number of spaces for each indentation level.

Value	Use Case
`2`	Default, common in YAML
`4`	More readable for deeply nested content

max-line-length

Maximum allowed characters per line.

Value	Use Case
`80`	Traditional terminal width
`100`	Common modern standard
`120`	Default, balances readability
`0`	Disable line length check

Examples

Trailing Whitespace

# Bad - has invisible spaces after the colon
name: CI   
on: push

# Good
name: CI
on: push

Multiple Blank Lines

# Bad
name: CI


on: push

# Good
name: CI

on: push

Line Length

# Bad - too long
- run: echo "This is an extremely long command that exceeds the maximum line length limit and should be split"

# Good - use YAML multiline
- run: |
    echo "This is a long command that has been"
    echo "split across multiple lines for readability"

Indentation

# Bad - using 4 spaces when 2 is expected
jobs:
    build:
        runs-on: ubuntu-latest

# Good - consistent 2-space indent
jobs:
  build:
    runs-on: ubuntu-latest