v14.0.2

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Changed

• improve negative number auto-detection test ([#​2428])
• update (dev) dependencies

v14.0.1

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Fixed

• broken markdown link in README ([#​2369])

Changed

• improve code readability by using optional chaining ([#​2394])
• use more idiomatic code with object spread instead ofObject.assign() ([#​2395])
• improve code readability usingstring.endsWith() instead ofstring.slice() ([#​2396])
• refactor.parseOptions() to process args array in-place ([#​2409])
• change private variadic support routines from._concatValue() to._collectValue() (change code fromarray.concat() toarray.push()) ([#​2410])
• update (dev) dependencies

v14.0.0

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Added

• support for groups of options and commands in the help using low-level.helpGroup() onOption andCommand, and higher-level.optionsGroup() and.commandsGroup() which can be used in chaining way to specify group title for following options/commands ([#​2328])
• support for unescaped negative numbers as option-arguments and command-arguments ([#​2339])
• TypeScript: addparseArg property toArgument class ([#​2359])

Fixed

• remove bogus leading space in help when option has default value but not a description ([#​2348])
• .configureOutput() now makes copy of settings instead of modifying in-place, fixing side-effects ([#​2350])

Changed

• Breaking: Commander 14 requires Node.js v20 or higher
• internal refactor ofHelp class adding.formatItemList() and.groupItems() methods ([#​2328])

v13.1.0

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Added

• support a pair of long option flags to allow a memorable shortened flag, like.option('--ws, --workspace') ([#​2312])

v13.0.0

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Added

• support multiple calls to.parse() with default settings ([#​2299])
• add.saveStateBeforeParse() and.restoreStateBeforeParse() for use by subclasses ([#​2299])
• style routines likestyleTitle() to add color to help using.configureHelp() or Help subclass ([#​2251])
• color related support in.configureOutput() forgetOutHasColors(),getErrHasColors(), andstripColor() ([#​2251])
• Help property forminWidthToWrap ([#​2251])
• Help methods fordisplayWidth(),boxWrap(),preformatted() et al ([#​2251])

Changed

• Breaking: excess command-arguments cause an error by default, see migration tips ([#​2223])
• Breaking: throw during Option construction for unsupported option flags, like multiple characters after single- ([#​2270])
  • note: support for dual long option flags added in Commander 13.1
• Breaking: throw on multiple calls to.parse() ifstoreOptionsAsProperties: true ([#​2299])
• TypeScript: include implicitthis in parameters for action handler callback ([#​2197])

Deleted

• Breaking:Help.wrap() refactored intoformatItem() andboxWrap() ([#​2251])

Migration Tips

Excess command-arguments

It is now an error for the user to specify more command-arguments than are expected. (allowExcessArguments is now false by default.)

Old code:

program.option('-p, --port <number>','port number');program.action((options)=>{console.log(program.args);});

Now shows an error:

$node example.js a b cerror: too many arguments. Expected 0 arguments but got 3.

You can declare the expected arguments. The help will then be more accurate too. Note that declaring
new arguments will change what is passed to the action handler.

program.option('-p, --port <number>','port number');program.argument('[args...]','remote command and arguments');// expecting zero or more argumentsprogram.action((args,options)=>{console.log(args);});

Or you could suppress the error, useful for minimising changes in legacy code.

program.option('-p, --port','port number');program.allowExcessArguments();program.action((options)=>{console.log(program.args);});

Stricter option flag parsing

Commander now throws an error for option flag combinations that are not supported.
In particular, a short flag with multiple characters is now an error.

program.option('-ws, --workspace');// throws error

A short option has a single character:

program.option('-w, --workspace');

Or from Commander 13.1 you can have an extra long flag instead of a short flag to allow a more memorable shortcut for the full name:

program.option('--ws, --workspace');

v12.1.0

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Added

• auto-detect special node flagsnode --eval andnode --print when call.parse() with no arguments ([#​2164])

Changed

• prefix require of Node.js core modules withnode: ([#​2170])
• format source files with Prettier ([#​2180])
• switch from StandardJS to directly calling ESLint for linting ([#​2153])
• extend security support for previous major version of Commander ([#​2150])

Removed

• removed unimplemented Option.fullDescription from TypeScript definition ([#​2191])

v12.0.0

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Added

• .addHelpOption() as another way of configuring built-in help option ([#​2006])
• .helpCommand() for configuring built-in help command ([#​2087])

Fixed

• Breaking: use non-zero exit code when spawned executable subcommand terminates due to a signal ([#​2023])
• Breaking: checkpassThroughOptions constraints when using.addCommand and throw if parent command does not have.enablePositionalOptions() enabled ([#​1937])

Changed

• Breaking: Commander 12 requires Node.js v18 or higher ([#​2027])
• Breaking: throw an error if add an option with a flag which is already in use ([#​2055])
• Breaking: throw an error if add a command with name or alias which is already in use ([#​2059])
• Breaking: throw error when calling.storeOptionsAsProperties() after setting an option value ([#​1928])
• replace non-standard JSDoc of@api private with documented@private ([#​1949])
• .addHelpCommand() now takes a Command (passing string or boolean still works as before but deprecated) ([#​2087])
• refactor internal implementation of built-in help option ([#​2006])
• refactor internal implementation of built-in help command ([#​2087])

Deprecated

• .addHelpCommand() passing string or boolean (use.helpCommand() or pass a Command) ([#​2087])

Removed

• Breaking: removed default export of a global Command instance from CommonJS (use the namedprogram export instead) ([#​2017])

Migration Tips

global program

If you are using thedeprecated default import of the global Command object, you need to switch to using a named import (or create a newCommand).

// const program = require('commander');const{ program}=require('commander');

option and command clashes

A couple of configuration problems now throw an error, which will pick up issues in existing programs:

• adding an option which uses the same flag as a previous option
• adding a command which uses the same name or alias as a previous command

v11.1.0

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Fixed

• TypeScript: updateOptionValueSource to allow any string, to match supported use of custom sources ([#​1983])
• TypeScript: add thatCommand.version() can also be used as getter ([#​1982])
• TypeScript: add null return type toCommands.executableDir(), for when not configured ([#​1965])
• subcommands with an executable handler and only a short help flag are now handled correctly by the parent's help command ([#​1930])

Added

• registeredArguments property onCommand with the array of definedArgument (likeCommand.options forOption) ([#​2010])
• TypeScript declarations for Option properties:envVar,presetArg ([#​2019])
• TypeScript declarations for Argument properties:argChoices,defaultValue,defaultValueDescription ([#​2019])
• example file which shows how to configure help to display any custom usage in the list of subcommands ([#​1896])

Changed

• (developer) refactor TypeScript configs for multiple use-cases, and enable checks in JavaScript files in supporting editors ([#​1969])

Deprecated

• Command._args was private anyway, but now available asregisteredArguments ([#​2010])

v11.0.0

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Fixed

• help command works when help option is disabled ([#​1864])

Changed

• leading and trailing spaces are now ignored by the .arguments() method ([#​1874])
• refine "types" exports for ESM to follow TypeScript guidelines ([#​1886])
• Breaking: Commander 11 requires Node.js v16 or higher

v10.0.1

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Added

• improvements to documentation ([#​1858], [#​1859], [#​1860])

Fixed

• remove unusedOption.optionFlags property from TypeScript definition ([#​1844])

Changed

• assume boolean option intended if caller passes string instead of hash to.implies() ([#​1854])

v10.0.0

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Added

• wrap command description in help ([#​1804])

Changed

• Breaking: Commander 10 requires Node.js v14 or higher

v9.5.0

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Added

• .getOptionValueSourceWithGlobals() ([#​1832])
• showGlobalOptions for.configureHelp{} andHelp ([#​1828])

v9.4.1

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Fixed

• .setOptionValue() now also clears option source ([#​1795])
• TypeScript: addimplied toOptionValueSource for option values set by using.implies() ([#​1794])
• TypeScript : addundefined to return type of.getOptionValueSource() ([#​1794])

Changed

• additions to README

v9.4.0

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Added

• preSubcommand hook called before direct subcommands ([#​1763])

Fixed

• exportInvalidOptionArgumentError in esm ([#​1756])

Changed

• update dependencies ([#​1767])

v9.3.0

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Added

• .summary() for a short summary to use instead of description when listing subcommands in help ([#​1726])
• Option.implies() to set other option values when the option is specified ([#​1724])
• updated Chinese README with 9.x changes ([#​1727])

Fixed

• TypeScript: addstring[] to.options() default value parameter type for use with variadic options ([#​1721])

Deprecated

• multi-character short option flag (e.g.-ws) ([#​1718])

v9.2.0

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Added

• conditional export of 'types' for upcoming TypeScript module resolution ([#​1703])
• example file showing two ways to add global options to subcommands ([#​1708])

Fixed

• detect option conflicts in parent commands of called subcommand ([#​1710])

Changed

• replace deprecatedString.prototype.substr ([#​1706])

v9.1.0

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Added

• Option.conflicts() to set conflicting options which can not be specified together ([#​1678])
• (developer) CodeQL configuration for GitHub Actions ([#​1698])

v9.0.0

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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 passOption 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 withexecutableFile ([#​1571])
• removed restriction that nested subcommands must specifyexecutableFile ([#​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 torequire.main.filename when script not known from arguments passed to.parse() (can supply details using.name(), and.executableDir() orexecutableFile) ([#​1571])

v8.3.0

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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

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Added

• .showSuggestionAfterError() to show suggestions after unknown command or unknown option ([#​1590])
• addOption 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 unimplementedOption methodargumentRejected

v8.1.0

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Added

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

v8.0.0

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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 asasync ([#​1513])
• Breaking:Help method.visibleArguments() returns array ofArgument ([#​1490])
• Breaking: Commander 8 requires Node.js 12 or higher ([#​1500])
• Breaking:CommanderError codecommander.invalidOptionArgument renamedcommander.invalidArgument ([#​1508])
• Breaking: TypeScript declaration for.addTextHelp() callback no longer allows result ofundefined, now juststring ([#​1516])
• refactorindex.tab into a file per class ([#​1522])
• remove help suggestion from "unknown command" error message (see.showHelpAfterError()) ([#​1534])
• Command property.arg initialised to empty array (was previously undefined) ([#​1529])
• update dependencies

Deprecated

• second parameter ofcmd.description(desc, argDescriptions) for adding argument descriptions ([#​1490])
  • (use new.argument(name, description) instead)
• InvalidOptionArgumentError (replaced byInvalidArgumentError) ([#​1508])

Removed

• Breaking: TypeScript declaration for default export of globalCommand object ([#​1520])
  • (still available as namedprogram 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();

v7.2.0

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Added

• TypeScript typing forparent property onCommand ([#​1475])
• TypeScript typing for.attributeName() onOption ([#​1483])
• support information in package ([#​1477])

Changed

• improvements to error messages, README, and tests
• update dependencies

v7.1.0

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Added

• support for named imports from ECMAScript modules ([#​1440])
• add.cjs to list of expected script file extensions ([#​1449])
• allow using option choices and variadic together ([#​1454])

Fixed

• replace use of deprecatedprocess.mainModule ([#​1448])
• regression for legacycommand('*') and call when command line includes options ([#​1464])
• regression foron('command:*', ...) and call when command line includes unknown options ([#​1464])
• display best error for combination of unknown command and unknown option (i.e. unknown command) ([#​1464])

Changed

• make TypeScript typings tests stricter ([#​1453])
• improvements to README and tests

v7.0.0

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Added

• .enablePositionalOptions() to let program and subcommand reuse same option ([#​1427])
• .passThroughOptions() to pass options through to other programs without needing-- ([#​1427])
• .allowExcessArguments(false) to show an error message if there are too many command-arguments on command line for the action handler ([#​1409])
• .configureOutput() to modify use of stdout and stderr or customise display of errors ([#​1387])
• use.addHelpText() to add text before or after the built-in help, for just current command or also for all subcommands ([#​1296])
• enhance Option class ([#​1331])
  • allow hiding options from help
  • allow restricting option arguments to a list of choices
  • allow setting how default value is shown in help
• .createOption() to support subclassing of automatically created options (like.createCommand()) ([#​1380])
• refactor the code generating the help into a separate public Help class ([#​1365])
  • support sorting subcommands and options in help
  • support specifying wrap width (columns)
  • allow subclassing Help class
  • allow configuring Help class without subclassing

Changed

• Breaking: options are stored safely by default, not as properties on the command ([#​1409])
  • this especially affects accessing options on program, useprogram.opts()
  • revert behaviour with.storeOptionsAsProperties()
• Breaking: action handlers are passed options and command separately ([#​1409])
• deprecated callback parameter to.help() and.outputHelp() (removed from README) ([#​1296])
• Breaking: errors now displayed usingprocess.stderr.write() instead ofconsole.error()
• deprecate.on('--help') (removed from README) ([#​1296])
• initialise the command description to empty string (previously undefined) ([#​1365])
• document and annotate deprecated routines ([#​1349])

Fixed

• wrapping bugs in help ([#​1365])
  • first line of command description was wrapping two characters early
  • pad width calculation was not including help option and help command
  • pad width calculation was including hidden options and commands
• improve backwards compatibility for custom command event listeners ([#​1403])

Deleted

• Breaking:.passCommandToAction() ([#​1409])
  • no longer needed as action handler is passed options and command
• Breaking: "extra arguments" parameter to action handler ([#​1409])
  • if being used to detect excess arguments, there is now an error available by setting.allowExcessArguments(false)

Migration Tips

The biggest change is the parsed option values. Previously the options were stored by default as properties on the command object, and now the options are stored separately.

If you wish to restore the old behaviour and get running quickly you can call.storeOptionsAsProperties().
To allow you to move to the new code patterns incrementally, the action handler will be passed the commandtwice,
to match the new "options" and "command" parameters (see below).

program options

Use the.opts() method to access the options. This is available on any command but is used most with the program.

program.option('-d, --debug');program.parse();// Old code before Commander 7if(program.debug)console.log(`Program name is${program.name()}`);

// New codeconstoptions=program.opts();if(options.debug)console.log(`Program name is${program.name()}`);

action handler

The action handler gets passed a parameter for each command-argument you declared. Previously by default the next parameter was the command object with the options as properties. Now the next two parameters are instead the options and the command. If you
only accessed the options there may be no code changes required.

program.command('compress <filename>').option('-t, --trace')// Old code before Commander 7.action((filename,cmd)=>{if(cmd.trace)console.log(`Command name is${cmd.name()}`);});

// New code.action((filename,options,command)=>{if(options.trace)console.log(`Command name is${command.name()}`);});

If you already set.storeOptionsAsProperties(false) you may still need to adjust your code.

program.command('compress <filename>').storeOptionsAsProperties(false).option('-t, --trace')// Old code before Commander 7.action((filename,command)=>{if(command.opts().trace)console.log(`Command name is${command.name()}`);});

// New code.action((filename,options,command)=>{if(command.opts().trace)console.log(`Command name is${command.name()}`);});

v6.2.1

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Fixed

• some tests failed if directory path included a space ([#​1390])

v6.2.0

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Added

• added 'tsx' file extension for stand-alone executable subcommands ([#​1368])
• documented second parameter to.description() to describe command arguments ([#​1353])
• documentation of special cases with options taking varying numbers of option-arguments ([#​1332])
• documentation for terminology ([#​1361])

Fixed

• add missing TypeScript definition for `.addHelpCommand()' ([#​1375])
• removed blank line after "Arguments:" in help, to match "Options:" and "Commands:" ([#​1360])

Changed

• update dependencies

v6.1.0

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Added

• include URL to relevant section of README for error for potential conflict between Command properties and option values ([#​1306])
• .combineFlagAndOptionalValue(false) to ease upgrade path from older versions of Commander ([#​1326])
• allow disabling the built-in help option using.helpOption(false) ([#​1325])
• allow just some arguments inargumentDescription to.description() ([#​1323])

Changed

• tidy async test and remove lint override ([#​1312])

Fixed

• executable subcommand launching when script path not known ([#​1322])

v6.0.0

Compare Source

Added

• add support for variadic options ([#​1250])
• allow options to be added with just a short flag ([#​1256])
  • Breaking the option property has same case as flag. e.g. flag-n accessed asopts().n (previously uppercase)
• Breaking throw an error if there might be a clash between option name and a Command property, with advice on how to resolve ([#​1275])

Fixed

• Options which contain -no- in the middle of the option flag should not be treated as negatable. ([#​1301])

v5.1.0

Compare Source

Added

• support for multiple command aliases, the first of which is shown in the auto-generated help ([#​531], [#​1236])
• configuration support inaddCommand() forhidden andisDefault ([#​1232])

Fixed

• omit masked help flags from the displayed help ([#​645], [#​1247])
• remove old short help flag when change help flags usinghelpOption ([#​1248])

Changed

• remove use ofarguments to improve auto-generated help in editors ([#​1235])
• rename.command() configurationnoHelp tohidden (but not remove old support) ([#​1232])
• improvements to documentation
• update dependencies
• update tested versions of node
• eliminate lint errors in TypeScript ([#​1208])

v5.0.0

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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 usesprocess.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 forcommands property ofCommand ([#​1184])
• exportprogram property ([#​1195])
• createCommand factory method to simplify subclassing ([#​1191])

Fixed

• preserve argument order in subcommands ([#​508] [#​962] [#​1138])
• do not emitcommand:* 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 renamedoperands 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, returnthis rather thanCommand ([#​1180])
• .parseAsync returnsPromise<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 functionnormalize (the functionality has been integrated intoparseOptions) ([#​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 useprogram.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 toisDefault:true with a named command.

If you want to continue combining short options with optional values as though they were boolean flags, setcombineFlagAndOptionalValue(false)
to expand-fb to-f -b rather than-f b.