Added

• support for nested commands with action-handlers ([#1] [#764] [#1149])
• .addCommand() for adding a separately configured command ([#764] [#1149])
• allow a non-executable to be set as the default command ([#742] [#1149])
• implicit help command when there are subcommands (previously only if executables) ([#1149])
• customise implicit help command with .addHelpCommand() ([#1149])
• display error message for unknown subcommand, by default ([#432] [#1088] [#1149])
• display help for missing subcommand, by default ([#1088] [#1149])
• combined short options as single argument may include boolean flags and value flag and value (e.g. -a -b -p 80 can be written as -abp80) ([#1145])
• .parseOption() includes short flag and long flag expansions ([#1145])
• .helpInformation() returns help text as a string, previously a private routine ([#1169])
• .parse() implicitly uses process.argv if arguments not specified ([#1172])
• optionally specify where .parse() arguments "from", if not following node conventions ([#512] [#1172])
• suggest help option along with unknown command error ([#1179])
• TypeScript definition for commands property of Command ([#1184])
• export program property ([#1195])
• createCommand factory method to simplify subclassing ([#1191])

Fixed

• preserve argument order in subcommands ([#508] [#962] [#1138])
• do not emit command:* for executable subcommands ([#809] [#1149])
• action handler called whether or not there are non-option arguments ([#1062] [#1149])
• combining option short flag and value in single argument now works for subcommands ([#1145])
• only add implicit help command when it will not conflict with other uses of argument ([#1153] [#1149])
• implicit help command works with command aliases ([#948] [#1149])
• options are validated whether or not there is an action handler ([#1149])

Changed

• Breaking .args contains command arguments with just recognised options removed ([#1032] [#1138])
• Breaking display error if required argument for command is missing ([#995] [#1149])
• tighten TypeScript definition of custom option processing function passed to .option() ([#1119])
• Breaking .allowUnknownOption() ([#802] [#1138])
  • unknown options included in arguments passed to command action handler
  • unknown options included in .args
• only recognised option short flags and long flags are expanded (e.g. -ab or --foo=bar) ([#1145])
• Breaking .parseOptions() ([#1138])
  • args in returned result renamed operands and does not include anything after first unknown option
  • unknown in returned result has arguments after first unknown option including operands, not just options and values
• Breaking .on('command:*', callback) and other command events passed (changed) results from .parseOptions, i.e. operands and unknown ([#1138])
• refactor Option from prototype to class ([#1133])
• refactor Command from prototype to class ([#1159])
• changes to error handling ([#1165])
  • throw for author error, not just display message
  • preflight for variadic error
  • add tips to missing subcommand executable
• TypeScript fluent return types changed to be more subclass friendly, return this rather than Command ([#1180])
• .parseAsync returns Promise<this> to be consistent with .parse() ([#1180])
• update dependencies

Removed

• removed EventEmitter from TypeScript definition for Command, eliminating implicit peer dependency on @types/node ([#1146])
• removed private function normalize (the functionality has been integrated into parseOptions) ([#1145])
• parseExpectedArgs is now private ([#1149])

Migration Tips

If you use .on('command:*') or more complicated tests to detect an unrecognised subcommand, you may be able to delete the code and rely on the default behaviour.

If you use program.args or more complicated tests to detect a missing subcommand, you may be able to delete the code and rely on the default behaviour.

If you use .command('*') to add a default command, you may be be able to switch to isDefault:true with a named command.

The new version differs by 53 commits.

• 2aad525 Update dependencies (#1214)
• f86d878 Add cli keyword (#1213)
• 83af0fd Prepare for 5.0.0 (#1211)
• f14df07 Add eslint settings for TypeScript (#1205)
• 95e0d19 5.0.0-4
• bd5a49e Add factory to CHANGELOG
• 8c3dd6f createCommand factory routine (#1191)
• 3c9f33f Say we support LTS, so do not need to update when node changes (#1204)
• 3cf8cff Expand typescript checks (#1198)
• a3f453f 5.0.0-3
• 87bfca6 Add CHANGELOG entries for 5.0.0-3
• 1757564 Use a tidier global command (#1200)
• 0a50bd6 Add program to exports (#1195)
• 77e511f Enable TypeScript checking of javascript, and resolve or suppress errors (#1194)
• 2491c76 URLEncode several chinese toc link

There are 53 commits in total.

See the full diff