Add support for dual long options when no short option (#2312)

Author: shadowspawn

CHANGELOG.md

@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 - *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()` if `storeOptionsAsProperties: true` ([#2299])
 - TypeScript: include implicit `this` in parameters for action handler callback ([#2197])
 

Readme.md

@@ -175,7 +175,15 @@ const program = new Command();
 
 ## Options
 
-Options are defined with the `.option()` method, also serving as documentation for the options. Each option can have a short flag (single character) and a long name, separated by a comma or space or vertical bar ('|').
+Options are defined with the `.option()` method, also serving as documentation for the options. Each option can have a short flag (single character) and a long name, separated by a comma or space or vertical bar ('|'). To allow a wider range of short-ish flags than just
+single characters, you may also have two long options. Examples:
+
+```js
+program
+  .option('-p, --port <number>', 'server port number')
+  .option('--trace', 'add extra debugging output')
+  .option('--ws, --workspace <name>', 'use a custom workspace')
+```
 
 The parsed options can be accessed by calling `.opts()` on a `Command` object, and are passed to the action handler.
 

docs/deprecated.md

@@ -12,11 +12,11 @@ They are currently still available for backwards compatibility, but should not b
     - [.command('\*')](#command)
     - [cmd.description(cmdDescription, argDescriptions)](#cmddescriptioncmddescription-argdescriptions)
     - [InvalidOptionArgumentError](#invalidoptionargumenterror)
-    - [Short option flag longer than a single character](#short-option-flag-longer-than-a-single-character)
     - [Import from `commander/esm.mjs`](#import-from-commanderesmmjs)
     - [cmd.\_args](#cmd_args)
     - [.addHelpCommand(string|boolean|undefined)](#addhelpcommandstringbooleanundefined)
   - [Removed](#removed)
+    - [Short option flag longer than a single character](#short-option-flag-longer-than-a-single-character)
     - [Default import of global Command object](#default-import-of-global-command-object)
 
 ### RegExp .option() parameter
@@ -168,12 +168,6 @@ function myParseInt(value, dummyPrevious) {
 
 Deprecated from Commander v8.
 
-### Short option flag longer than a single character
-
-Short option flags like `-ws` were never supported, but the old README did not make this clear. The README now states that short options are a single character.
-
-README updated in Commander v3. Deprecated from Commander v9.
-
 ### Import from `commander/esm.mjs`
 
 The first support for named imports required an explicit entry file.
@@ -232,6 +226,15 @@ program.addHelpCommand(new Command('assist').argument('[command]').description('
 
 ## Removed
 
+### Short option flag longer than a single character
+
+Short option flags like `-ws` were never supported, but the old README did not make this clear. The README now states that short options are a single character.
+
+- README updated in Commander v3.
+- Deprecated from Commander v9.
+- Throws an exception in Commander v13. Deprecated and gone!
+- Replacement added in Commander v13.1 with support for dual long options, like `--ws, --workspace`.
+
 ### Default import of global Command object
 
 The default import was a global Command object.

lib/command.js

@@ -756,7 +756,7 @@ Expecting one of '${allowedValues.join("', '")}'`);
    * @example
    * program
    *     .option('-p, --pepper', 'add pepper')
-   *     .option('-p, --pizza-type <TYPE>', 'type of pizza') // required option-argument
+   *     .option('--pt, --pizza-type <TYPE>', 'type of pizza') // required option-argument
    *     .option('-c, --cheese [CHEESE]', 'add extra cheese', 'mozzarella') // optional option-argument with default
    *     .option('-t, --tip <VALUE>', 'add tip to purchase cost', parseFloat) // custom parse function
    *

lib/option.js

@@ -18,7 +18,7 @@ class Option {
     this.variadic = /\w\.\.\.[>\]]$/.test(flags); // The option can take multiple values.
     this.mandatory = false; // The option must have a value after parsing, which usually means it must be specified on command line.
     const optionFlags = splitOptionFlags(flags);
-    this.short = optionFlags.shortFlag;
+    this.short = optionFlags.shortFlag; // May be a short flag, undefined, or even a long flag (if option has two long flags).
     this.long = optionFlags.longFlag;
     this.negate = false;
     if (this.long) {
@@ -321,25 +321,44 @@ function splitOptionFlags(flags) {
   const longFlagExp = /^--[^-]/;
 
   const flagParts = flags.split(/[ |,]+/).concat('guard');
+  // Normal is short and/or long.
   if (shortFlagExp.test(flagParts[0])) shortFlag = flagParts.shift();
   if (longFlagExp.test(flagParts[0])) longFlag = flagParts.shift();
+  // Long then short. Rarely used but fine.
+  if (!shortFlag && shortFlagExp.test(flagParts[0]))
+    shortFlag = flagParts.shift();
+  // Allow two long flags, like '--ws, --workspace'
+  // This is the supported way to have a shortish option flag.
+  if (!shortFlag && longFlagExp.test(flagParts[0])) {
+    shortFlag = longFlag;
+    longFlag = flagParts.shift();
+  }
 
-  // Check for some unsupported flags that people try.
-  if (/^-[^-][^-]/.test(flagParts[0]))
-    throw new Error(
-      `invalid Option flags, short option is dash and single character: '${flags}'`,
-    );
-  if (shortFlag && shortFlagExp.test(flagParts[0]))
-    throw new Error(
-      `invalid Option flags, more than one short flag: '${flags}'`,
-    );
-  if (longFlag && longFlagExp.test(flagParts[0]))
+  // Check for unprocessed flag. Fail noisily rather than silently ignore.
+  if (flagParts[0].startsWith('-')) {
+    const unsupportedFlag = flagParts[0];
+    const baseError = `option creation failed due to '${unsupportedFlag}' in option flags '${flags}'`;
+    if (/^-[^-][^-]/.test(unsupportedFlag))
+      throw new Error(
+        `${baseError}
+- a short flag is a single dash and a single character
+  - either use a single dash and a single character (for a short flag)
+  - or use a double dash for a long option (and can have two, like '--ws, --workspace')`,
+      );
+    if (shortFlagExp.test(unsupportedFlag))
+      throw new Error(`${baseError}
+- too many short flags`);
+    if (longFlagExp.test(unsupportedFlag))
+      throw new Error(`${baseError}
+- too many long flags`);
+
+    throw new Error(`${baseError}
+- unrecognised flag format`);
+  }
+  if (shortFlag === undefined && longFlag === undefined)
     throw new Error(
-      `invalid Option flags, more than one long flag: '${flags}'`,
+      `option creation failed due to no flags found in '${flags}'.`,
     );
-  // Generic error if failed to find a flag or an unexpected flag left over.
-  if (!(shortFlag || longFlag) || flagParts[0].startsWith('-'))
-    throw new Error(`invalid Option flags: '${flags}'`);
 
   return { shortFlag, longFlag };
 }

tests/option.bad-flags.test.js

@@ -5,24 +5,26 @@ test.each([
   { flags: '-a, -b' }, // too many short flags
   { flags: '-a, -b <value>' },
   { flags: '-a, -b, --long' },
-  { flags: '--one, --two' }, // too many long flags
-  { flags: '--one, --two [value]' },
+  { flags: '--one, --two, --three' }, // too many long flags
   { flags: '-ws' }, // short flag with more than one character
+  { flags: '---triple' }, // double dash not followed by a non-dash
   { flags: 'sdkjhskjh' }, // oops, no flags
   { flags: '-a,-b' }, // try all the separators
   { flags: '-a|-b' },
   { flags: '-a -b' },
 ])('when construct Option with flags %p then throw', ({ flags }) => {
   expect(() => {
     new Option(flags);
-  }).toThrow(/^invalid Option flags/);
+  }).toThrow(/^option creation failed/);
 });
 
 // Check that supported flags do not throw.
 test.each([
   { flags: '-s' }, // single short
   { flags: '--long' }, // single long
   { flags: '-b, --both' }, // short and long
+  { flags: '--both, -b' }, // long and short
+  { flags: '--ws, --workspace' }, // two long (morally shortish and long)
   { flags: '-b,--both <comma>' },
   { flags: '-b|--both <bar>' },
   { flags: '-b --both [space]' },

typings/index.d.ts

@@ -617,7 +617,7 @@ export class Command {
    * ```js
    * program
    *     .option('-p, --pepper', 'add pepper')
-   *     .option('-p, --pizza-type <TYPE>', 'type of pizza') // required option-argument
+   *     .option('--pt, --pizza-type <TYPE>', 'type of pizza') // required option-argument
    *     .option('-c, --cheese [CHEESE]', 'add extra cheese', 'mozzarella') // optional option-argument with default
    *     .option('-t, --tip <VALUE>', 'add tip to purchase cost', parseFloat) // custom parse function
    * ```