Locals

Local Values in Testform assign names to computed expressions and data transformations, reducing repetition and keeping test suites maintainable.

Just like the locals block in Terraform, local values in Testform are declared in locals.yml (or main.yml) and referenced via ${local.<name>}.

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1. Local Declarations & AST Expressions

Testform includes a built-in sandboxed AST expression engine supporting standard HCL transformation functions:

locals.yml

locals:
  # Text transformation
  env_clean: "${lower(trim(var.environment))}"

  # Format with placeholders
  base_url: "${format('https://%s.%s', local.env_clean, var.domain)}"
  login_endpoint: "${local.base_url}/auth/v1/login"

  # Collections & fallbacks
  default_tags: "${split(',', 'e2e,smoke,regression')}"
  api_key: "${coalesce(env('CI_API_KEY'), 'local-dev-key')}"

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2. Supported Functions Catalog

Category	Functions	Description / Example
String	lower, upper	Case conversion: ${lower(var.env)}
	trim, trimprefix, trimsuffix	Strip whitespace or affixes: ${trimprefix(var.url, 'https://')}
	format, replace, substr	Formatting & substring: ${format('%s/v1', var.host)}, ${substr(var.name, 0, 4)}
	split, join	Delimiter split & join: ${split(',', 'a,b')}, ${join('-', ['x', 'y'])}
Collections	contains	Element check: ${contains(['dev', 'staging'], var.env)}
	length	Size of array, map, or string: ${length(var.tags)}
	element, slice	Index element retrieval and slicing: ${element(var.list, 0)}
	coalesce	Returns first non-null/non-empty value: ${coalesce(env('TOKEN'), 'default')}
	lookup, merge	Map lookup and object merging
System & Env	env	Read environment variables: ${env('GITHUB_TOKEN')}
	uuid, timestamp	Generate UUIDs and ISO timestamps
	jsonencode, jsondecode	JSON serialization and parsing
	file	Read local file contents: ${file('fixtures/user.json')}

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3. Multi-Pass Resolution

Testform resolves transitive dependencies across locals and variables up to 3 passes:

1. ${var.domain} evaluates to "company.com".
2. ${local.base_url} evaluates using ${format(...)}.
3. ${local.login_endpoint} evaluates to "https://staging.company.com/auth/v1/login".

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4. Usage in Gherkin Scenarios

Scenario: Dynamic endpoint test
  Given browser opens "${local.login_endpoint}"
  When user submits valid credentials
  Then user is redirected to the main dashboard