Style Engine¶

The style engine enforces consistent naming conventions and organizational patterns in your Terraform code.

Overview¶

The style engine checks for naming conventions, attribute ordering, and structural consistency to maintain a uniform codebase.

Usage¶

# Run style checks
terratidy style

# Fix style issues
terratidy style --fix

# Check specific directory
terratidy style ./modules/

style --fix vs fmt vs fmt --all¶

The style engine focuses on semantic organization rather than whitespace formatting:

Command	HCL Formatting	Style Fixes	Use Case
`terratidy fmt`	✓		Standard formatting (whitespace, alignment)
`terratidy style --fix`		✓	Style fixes only (naming, block ordering)
`terratidy fmt --all`	✓	✓	Complete formatting and style fixes

Use style --fix when you only want to fix style issues without reformatting whitespace. Use fmt --all or terratidy fix when you want both HCL formatting and style fixes applied together.

Configuration¶

engines:
  style:
    enabled: true

# Override individual style rules
overrides:
  rules:
    style.block-label-case:
      enabled: true
      severity: warning
    style.meta-arguments-order:
      enabled: true
    style.variable-naming:
      enabled: true

Rules¶

Naming Conventions¶

Rule	Description
`resource-naming`	Resources should follow naming convention
`variable-naming`	Variables should follow naming convention
`output-naming`	Outputs should follow naming convention
`module-naming`	Module calls should follow naming convention

Attribute Ordering¶

The style engine can enforce a consistent attribute order within blocks:

Meta-arguments (count, for_each, provider)
Required attributes
Optional attributes
Nested blocks
Lifecycle meta-arguments (depends_on, lifecycle)

File Organization¶

Rule	Description
`variables-file`	Variables should be in `variables.tf`
`outputs-file`	Outputs should be in `outputs.tf`
`providers-file`	Provider configs should be in `providers.tf`

Example¶

Before:

resource "aws_instance" "MyServer" {
  lifecycle {
    create_before_destroy = true
  }
  ami           = var.ami_id
  instance_type = "t2.micro"
  count         = 2
}

After (with fixes applied):

resource "aws_instance" "my_server" {
  count         = 2
  ami           = var.ami_id
  instance_type = "t2.micro"

  lifecycle {
    create_before_destroy = true
  }
}

Disabling Rules¶

Disable specific rules inline:

# terratidy:ignore:resource-naming
resource "aws_instance" "MyServer" {
  # ...
}

Or globally in configuration:

overrides:
  rules:
    style.block-label-case:
      enabled: false