v9.0.0

Added

• simpler ECMAScript import (#1589)
• Option.preset() allows specifying value/arg for option when used without option-argument (especially optional, but also boolean option) (#1652)
• .executableDir() for custom search for subcommands (#1571)
• throw with helpful message if pass Option to .option() or .requiredOption() (#1655)
• .error() for generating errors from client code just like Commander generated errors, with support for .configureOutput (), .exitOverride(), and .showHelpAfterError() (#1675)
• .optsWithGlobals() to return merged local and global options (#1671)

Changed

• Breaking: Commander 9 requires Node.js v12.20.0 or higher
• update package-lock.json to lockfile@2 format (#1659)
• showSuggestionAfterError is now on by default (#1657)
• Breaking: default value specified for boolean option now always used as default value (see .preset() to match some previous behaviours) (#1652)
• default value for boolean option only shown in help if true/false (#1652)
• use command name as prefix for subcommand stand-alone executable name (with fallback to script name for backwards compatibility) (#1571)
• allow absolute path with executableFile (#1571)
• removed restriction that nested subcommands must specify executableFile (#1571)
• TypeScript: allow passing readonly string array to .choices() (#1667)
• TypeScript: allow passing readonly string array to .parse(), .parseAsync(), .aliases() (#1669)

Fixed

• option with optional argument not supplied on command line now works when option already has a value, whether from default value or from previous arguments (#1652)

Removed

• Breaking: removed internal fallback to require.main.filename when script not known from arguments passed to .parse()
  (can supply details using .name(), and .executableDir() or executableFile) (#1571)

9.0.0-1

Added

• .error() for generating errors from client code just like Commander generated errors, with support for .configureOutput(), .exitOverride(), and .showHelpAfterError() (#1675)
• .optsWithGlobals() to return merged local and global options (#1671)

9.0.0-0

Added

• simpler ECMAScript import (#1589)
• Option.preset() allows specifying value/arg for option when used without option-argument (especially optional, but also boolean option) (#1652)
• .executableDir() for custom search for subcommands (#1571)
• throw with helpful message if pass Option to .option() or .requiredOption() (#1655)

Changed

• Breaking: Commander 9 requires Node.js v12.20.0 or higher
• update package-lock.json to lockfile@2 format (#1659)
• showSuggestionAfterError is now on by default (#1657)
• Breaking: default value specified for boolean option now always used as default value (see .preset() to match some previous behaviours) (#1652)
• default value for boolean option only shown in help if true/false (#1652)
• use command name as prefix for subcommand stand-alone executable name (with fallback to script name for backwards compatibility) (#1571)
• allow absolute path with executableFile (#1571)
• removed restriction that nested subcommands must specify executableFile (#1571)

Fixed

• option with optional argument not supplied on command line now works when option already has a value, whether from default value or from previous arguments (#1652)

Removed

• Breaking: removed internal fallback to require.main.filename when script not known from arguments passed to .parse() (can supply details using .name(), and .executableDir() or executableFile) (#1571)

v8.3.0

Added

• .getOptionValueSource() and .setOptionValueWithSource(), where expected values for source are one of 'default', 'env', 'config', 'cli' (#1613)

Deprecated

• .command('*'), use default command instead (#1612)
• on('command:*'), use .showSuggestionAfterError() instead (#1612)

v8.2.0

Added

• .showSuggestionAfterError() to show suggestions after unknown command or unknown option (#1590)
• add Option support for values from environment variables using .env() (#1587)

Changed

• show error for unknown global option before subcommand (rather than just help) (#1590)

Removed

• TypeScript declaration of unimplemented Option method argumentRejected

v8.1.0

Added

• .copyInheritedSettings() (#1557)
• update Chinese translations for Commander v8 (#1570)
• Argument methods for .argRequired() and .argOptional() (#1567)

v8.0.0

Added

• .argument(name, description) for adding command-arguments (#1490)
  • supports default value for optional command-arguments (#1508)
  • supports custom processing function (#1508)
• .createArgument() factory method (#1497)
• .addArgument() (#1490)
• Argument supports .choices() (#1525)
• .showHelpAfterError() to display full help or a custom message after an error (#1534)
• .hook() with support for 'preAction' and 'postAction' callbacks (#1514)
• client typing of .opts() return type using TypeScript generics (#1539)
• the number of command-arguments is checked for programs without an action handler (#1502)
• .getOptionValue() and .setOptionValue() (#1521)

Changed

• refactor and simplify TypeScript declarations (with no default export) (#1520)
• .parseAsync() is now declared as async (#1513)
• Breaking: Help method .visibleArguments() returns array of Argument (#1490)
• Breaking: Commander 8 requires Node.js 12 or higher (#1500)
• Breaking: CommanderError code commander.invalidOptionArgument renamed commander.invalidArgument (#1508)
• Breaking: TypeScript declaration for .addTextHelp() callback no longer allows result of undefined, now just string (#1516)
• refactor index.tab into a file per class (#1522)
• remove help suggestion from "unknown command" error message (see .showHelpAfteError()) (#1534)
• Command property .arg initialised to empty array (was previously undefined) (#1529)
• update dependencies

Deprecated

• second parameter of cmd.description(desc, argDescriptions) for adding argument descriptions (#1490)
  • (use new .argument(name, description) instead)
• InvalidOptionArgumentError (replaced by InvalidArgumentError) (#1508)

Removed

• Breaking: TypeScript declaration for default export of global Command object (#1520)
  • (still available as named program export)

Migration Tips

If you have a simple program without an action handler, you will now get an error if
there are missing command-arguments.

program
  .option('-d, --debug')
  .arguments('<file>');
program.parse();

$ node trivial.js 
error: missing required argument 'file'

If you want to show the help in this situation, you could check the arguments before parsing:

if (process.argv.length === 2)
  program.help();
program.parse();

Or, you might choose to show the help after any user error:

program.showHelpAfterError();

8.0.0-2

Added

• .showHelpAfterError() to display full help or a custom message after an error (#1534)
• custom argument processing function also called without action handler (only with action handler in v8.0.0-0) (#1529)

Changed

• remove help suggestion from "unknown command" error message (see .showHelpAfteError()) (#1534)
• Command property .arg initialised to empty array (was previously undefined) (#1529)

8.0.0-1

Added

• .addArgument() (#1490)
• Argument supports .choices() (#1525)
• client typing of .opts() return type using TypeScript generics (#1539)

Changed

• refactor index.tab into a file per class (#1522)
• update dependencies

8.0.0-0

Added

• .getOptionValue() and .setOptionValue() (#1521)
• .hook() with support for 'preAction' and 'postAction' callbacks (#1514)
• .argument(name, description) for adding command-arguments (#1490)
  • supports default value for optional command-arguments (#1508)
  • supports custom processing function (#1508)
• .createArgument() factory method (#1497)
• the number of command-arguments is checked for programs without an action handler (#1502)

Changed

• refactor and simplify TypeScript declarations (with no default export) (#1520)
• .parseAsync() is now declared as async (#1513)
• Breaking: Help method .visibleArguments() returns array of Argument (#1490)
• Breaking: Commander 8 requires Node.js 12 or higher (#1500)
• Breaking: CommanderError code commander.invalidOptionArgument renamed commander.invalidArgument (#1508)
• Breaking: TypeScript declaration for .addTextHelp() callback no longer allows result of undefined, now just string (#1516)

Deprecated

• second parameter of cmd.description(desc, argDescriptions) for adding argument descriptions (#1490)
  • (use new .argument(name, description) instead)
• InvalidOptionArgumentError (replaced by InvalidArgumentError) (#1508)

Removed

• Breaking: TypeScript declaration for default export of global Command object (#1520)
  • (still available as named program export)