dart-build-cli-app

Building Dart CLI Applications

Contents

• Project Setup & Architecture
• Argument Parsing & Command Routing
• Execution & Error Handling
• Testing CLI Applications
• Compilation & Distribution
• Workflows
• Examples

Project Setup & Architecture

Initialize new CLI projects using the official Dart template to ensure standard directory structures.

• Run dart create -t cli <project_name> to scaffold a console application with basic argument parsing.
• Place executable entry points (files containing main()) exclusively in the bin/ directory.
• Place internal implementation logic in lib/src/ and expose public APIs via lib/<project_name>.dart.
• Enforce formatting in CI environments by running dart format . --set-exit-if-changed. This returns exit code 1 if formatting violations exist.

Argument Parsing & Command Routing

Import the args package to manage command-line arguments, flags, and subcommands.

• If building a simple script: Use ArgParser directly to define flags (addFlag) and options (addOption).
• If building a complex, multi-command CLI (like git): Implement CommandRunner and extend Command for each subcommand.
• Define global arguments on the CommandRunner.argParser and command-specific arguments on the individual Command.argParser.
• Catch UsageException to gracefully handle invalid arguments and display the automatically generated help text.
• Validate Help Text Accuracy: Ensure the help text provides all necessary information to run the tool. If the help text references a compiled executable name, and the user needs to add it to their PATH to run it that way, provide clear instructions on how to do so in the help text or description.

Execution & Error Handling

Leverage the io and stack_trace packages to build robust, production-ready CLI tools.