Struct ExistsCommandController 

pub struct ExistsCommandController { /* private fields */ }

Presentation layer controller for exists command workflow

Checks whether an environment exists and outputs a boolean result. This is a read-only command that checks local data only.

Responsibilities

• Validate environment name format
• Delegate to application layer for existence check
• Output true or false to stdout

Output Contract

• stdout: true or false (bare value, valid JSON)
• exit code 0: Command completed successfully (result is on stdout)
• exit code 1: An error occurred (e.g., repository failure)

Architecture

This controller intentionally does NOT use ProgressReporter because the exists check is a sub-millisecond operation. Progress reporting would add noise without value.

Implementations

impl ExistsCommandController

pub fn new( repository: Arc<dyn EnvironmentRepository + Send + Sync>, user_output: Arc<ReentrantMutex<RefCell<UserOutput>>>, ) -> Self

Create a new ExistsCommandController with dependencies

Arguments

• repository - Environment repository for checking existence
• user_output - Shared output service for result display

pub fn execute( &self, environment_name: &str, output_format: OutputFormat, ) -> Result<(), ExistsSubcommandError>

Execute the exists command workflow

This method orchestrates a simple workflow:

1. Validate environment name
2. Check existence via application layer
3. Output boolean result to stdout

Arguments

• environment_name - Name of the environment to check
• output_format - Output format (Text or Json)

Errors

Returns ExistsSubcommandError if any step fails