Support options with only a short flag (#1256)

* Support short flag alone

* Weaken option parsing for backwards compatibility

* Have .version allow short only flag

* Add tests for lone short and long flags

Readme.md

@@ -292,7 +292,7 @@ $ ./examples/pizza -V
 ```
 
 You may change the flags and description by passing additional parameters to the `version` method, using
-the same syntax for flags as the `option` method. The version flags can be named anything, but a long name is required.
+the same syntax for flags as the `option` method.
 
 ```js
 program.version('0.0.1', '-v, --vers', 'output the current version');

index.js

@@ -23,10 +23,13 @@ class Option {
     this.required = flags.includes('<'); // A value must be supplied when the option is specified.
     this.optional = flags.includes('['); // A value is optional when the option is specified.
     this.mandatory = false; // The option must have a value after parsing, which usually means it must be specified on command line.
-    this.negate = flags.includes('-no-');
-    const flagParts = flags.split(/[ ,|]+/);
-    if (flagParts.length > 1 && !/^[[<]/.test(flagParts[1])) this.short = flagParts.shift();
-    this.long = flagParts.shift();
+    const optionFlags = _parseOptionFlags(flags);
+    this.short = optionFlags.shortFlag;
+    this.long = optionFlags.longFlag;
+    this.negate = false;
+    if (this.long) {
+      this.negate = this.long.startsWith('--no-');
+    }
     this.description = description || '';
     this.defaultValue = undefined;
   }
@@ -39,7 +42,10 @@ class Option {
    */
 
   name() {
-    return this.long.replace(/^--/, '');
+    if (this.long) {
+      return this.long.replace(/^--/, '');
+    }
+    return this.short.replace(/^-/, '');
   };
 
   /**
@@ -1187,9 +1193,9 @@ class Command extends EventEmitter {
     flags = flags || '-V, --version';
     description = description || 'output the version number';
     const versionOption = new Option(flags, description);
-    this._versionOptionName = versionOption.long.substr(2) || 'version';
+    this._versionOptionName = versionOption.attributeName();
     this.options.push(versionOption);
-    this.on('option:' + this._versionOptionName, () => {
+    this.on('option:' + versionOption.name(), () => {
       process.stdout.write(str + '\n');
       this._exit(0, 'commander.version', str);
     });
@@ -1552,12 +1558,9 @@ class Command extends EventEmitter {
     this._helpFlags = flags || this._helpFlags;
     this._helpDescription = description || this._helpDescription;
 
-    const splitFlags = this._helpFlags.split(/[ ,|]+/);
-
-    this._helpShortFlag = undefined;
-    if (splitFlags.length > 1) this._helpShortFlag = splitFlags.shift();
-
-    this._helpLongFlag = splitFlags.shift();
+    const helpFlags = _parseOptionFlags(this._helpFlags);
+    this._helpShortFlag = helpFlags.shortFlag;
+    this._helpLongFlag = helpFlags.longFlag;
 
     return this;
   };
@@ -1708,6 +1711,28 @@ function humanReadableArgName(arg) {
     : '[' + nameOutput + ']';
 }
 
+/**
+ * Parse the short and long flag out of something like '-m,--mixed <value>'
+ *
+ * @api private
+ */
+
+function _parseOptionFlags(flags) {
+  let shortFlag;
+  let longFlag;
+  // Use original very loose parsing to maintain backwards compatibility for now,
+  // which allowed for example unintended `-sw, --short-word` [sic].
+  const flagParts = flags.split(/[ |,]+/);
+  if (flagParts.length > 1 && !/^[[<]/.test(flagParts[1])) shortFlag = flagParts.shift();
+  longFlag = flagParts.shift();
+  // Add support for lone short flag without significantly changing parsing!
+  if (!shortFlag && /^-[^-]$/.test(longFlag)) {
+    shortFlag = longFlag;
+    longFlag = undefined;
+  }
+  return { shortFlag, longFlag };
+}
+
 /**
  * Scan arguments and increment port number for inspect calls (to avoid conflicts when spawning new command).
  *

tests/command.helpOption.test.js

@@ -1,22 +1,66 @@
 const commander = require('../');
 
-test('when helpOption has custom flags then custom flag invokes help', () => {
-  // Optional. Suppress normal output to keep test output clean.
-  const writeSpy = jest.spyOn(process.stdout, 'write').mockImplementation(() => { });
-  const program = new commander.Command();
-  program
-    .exitOverride()
-    .helpOption('--custom-help', 'custom help output');
-  expect(() => {
-    program.parse(['node', 'test', '--custom-help']);
-  }).toThrow('(outputHelp)');
-  writeSpy.mockClear();
-});
+describe('helpOption', () => {
+  let writeSpy;
+
+  beforeAll(() => {
+    // Optional. Suppress normal output to keep test output clean.
+    writeSpy = jest.spyOn(process.stdout, 'write').mockImplementation(() => { });
+  });
+
+  afterEach(() => {
+    writeSpy.mockClear();
+  });
+
+  afterAll(() => {
+    writeSpy.mockRestore();
+  });
+
+  test('when helpOption has custom flags then custom short flag invokes help', () => {
+    const program = new commander.Command();
+    program
+      .exitOverride()
+      .helpOption('-c,--custom-help', 'custom help output');
+    expect(() => {
+      program.parse(['-c'], { from: 'user' });
+    }).toThrow('(outputHelp)');
+  });
+
+  test('when helpOption has custom flags then custom long flag invokes help', () => {
+    const program = new commander.Command();
+    program
+      .exitOverride()
+      .helpOption('-c,--custom-help', 'custom help output');
+    expect(() => {
+      program.parse(['--custom-help'], { from: 'user' });
+    }).toThrow('(outputHelp)');
+  });
+
+  test('when helpOption has just custom short flag then custom short flag invokes help', () => {
+    const program = new commander.Command();
+    program
+      .exitOverride()
+      .helpOption('-c', 'custom help output');
+    expect(() => {
+      program.parse(['-c'], { from: 'user' });
+    }).toThrow('(outputHelp)');
+  });
+
+  test('when helpOption has just custom long flag then custom long flag invokes help', () => {
+    const program = new commander.Command();
+    program
+      .exitOverride()
+      .helpOption('--custom-help', 'custom help output');
+    expect(() => {
+      program.parse(['--custom-help'], { from: 'user' });
+    }).toThrow('(outputHelp)');
+  });
 
-test('when helpOption has custom description then helpInformation include custom description', () => {
-  const program = new commander.Command();
-  program
-    .helpOption('-C,--custom-help', 'custom help output');
-  const helpInformation = program.helpInformation();
-  expect(helpInformation).toMatch(/-C,--custom-help +custom help output/);
+  test('when helpOption has custom description then helpInformation include custom description', () => {
+    const program = new commander.Command();
+    program
+      .helpOption('-C,--custom-help', 'custom help output');
+    const helpInformation = program.helpInformation();
+    expect(helpInformation).toMatch(/-C,--custom-help +custom help output/);
+  });
 });

tests/helpwrap.test.js

@@ -8,16 +8,16 @@ test('when long option description then wrap and indent', () => {
   process.stdout.columns = 80;
   const program = new commander.Command();
   program
-    .option('-x -extra-long-option-switch', 'kjsahdkajshkahd kajhsd akhds kashd kajhs dkha dkh aksd ka dkha kdh kasd ka kahs dkh sdkh askdh aksd kashdk ahsd kahs dkha skdh');
+    .option('-x --extra-long-option-switch', 'kjsahdkajshkahd kajhsd akhds kashd kajhs dkha dkh aksd ka dkha kdh kasd ka kahs dkh sdkh askdh aksd kashdk ahsd kahs dkha skdh');
 
   const expectedOutput =
 `Usage:  [options]
 
 Options:
-  -x -extra-long-option-switch  kjsahdkajshkahd kajhsd akhds kashd kajhs dkha
-                                dkh aksd ka dkha kdh kasd ka kahs dkh sdkh
-                                askdh aksd kashdk ahsd kahs dkha skdh
-  -h, --help                    display help for command
+  -x --extra-long-option-switch  kjsahdkajshkahd kajhsd akhds kashd kajhs dkha
+                                 dkh aksd ka dkha kdh kasd ka kahs dkh sdkh
+                                 askdh aksd kashdk ahsd kahs dkha skdh
+  -h, --help                     display help for command
 `;
 
   expect(program.helpInformation()).toBe(expectedOutput);
@@ -29,15 +29,15 @@ test('when long option description and default then wrap and indent', () => {
   process.stdout.columns = 80;
   const program = new commander.Command();
   program
-    .option('-x -extra-long-option <value>', 'kjsahdkajshkahd kajhsd akhds', 'aaa bbb ccc ddd eee fff ggg');
+    .option('-x --extra-long-option <value>', 'kjsahdkajshkahd kajhsd akhds', 'aaa bbb ccc ddd eee fff ggg');
 
   const expectedOutput =
 `Usage:  [options]
 
 Options:
-  -x -extra-long-option <value>  kjsahdkajshkahd kajhsd akhds (default: "aaa
-                                 bbb ccc ddd eee fff ggg")
-  -h, --help                     display help for command
+  -x --extra-long-option <value>  kjsahdkajshkahd kajhsd akhds (default: "aaa
+                                  bbb ccc ddd eee fff ggg")
+  -h, --help                      display help for command
 `;
 
   expect(program.helpInformation()).toBe(expectedOutput);
@@ -49,20 +49,20 @@ test('when long command description then wrap and indent', () => {
   process.stdout.columns = 80;
   const program = new commander.Command();
   program
-    .option('-x -extra-long-option-switch', 'x')
+    .option('-x --extra-long-option-switch', 'x')
     .command('alpha', 'Lorem mollit quis dolor ex do eu quis ad insa a commodo esse.');
 
   const expectedOutput =
 `Usage:  [options] [command]
 
 Options:
-  -x -extra-long-option-switch  x
-  -h, --help                    display help for command
+  -x --extra-long-option-switch  x
+  -h, --help                     display help for command
 
 Commands:
-  alpha                         Lorem mollit quis dolor ex do eu quis ad insa
-                                a commodo esse.
-  help [command]                display help for command
+  alpha                          Lorem mollit quis dolor ex do eu quis ad
+                                 insa a commodo esse.
+  help [command]                 display help for command
 `;
 
   expect(program.helpInformation()).toBe(expectedOutput);

tests/options.flags.test.js

@@ -2,15 +2,23 @@ const commander = require('../');
 
 // Test the various ways flags can be specified in the first parameter to `.option`
 
+test('when only short flag defined and not specified then value is undefined', () => {
+  const program = new commander.Command();
+  program
+    .option('-p', 'add pepper');
+  program.parse(['node', 'test']);
+  expect(program.p).toBeUndefined();
+});
+
+// Sanity check that pepper is not true normally, as otherwise all the following tests would pass for thr wrong reasons!
 test('when only short flag defined and specified then value is true', () => {
   const program = new commander.Command();
   program
     .option('-p', 'add pepper');
   program.parse(['node', 'test', '-p']);
-  expect(program.P).toBe(true);
+  expect(program.p).toBe(true);
 });
 
-// Sanity check that pepper is not true normally, as otherwise all the following tests would pass for thr wrong reasons!
 test('when only long flag defined and not specified then value is undefined', () => {
   const program = new commander.Command();
   program

tests/options.version.test.js

@@ -89,6 +89,18 @@ describe('.version', () => {
     }).toThrow(myVersion);
   });
 
+  test('when specify just custom short flag then display version', () => {
+    const myVersion = '1.2.3';
+    const program = new commander.Command();
+    program
+      .exitOverride()
+      .version(myVersion, '-r');
+
+    expect(() => {
+      program.parse(['node', 'test', '-r']);
+    }).toThrow(myVersion);
+  });
+
   test('when specify custom long flag then display version', () => {
     const myVersion = '1.2.3';
     const program = new commander.Command();
@@ -101,6 +113,18 @@ describe('.version', () => {
     }).toThrow(myVersion);
   });
 
+  test('when specify just custom long flag then display version', () => {
+    const myVersion = '1.2.3';
+    const program = new commander.Command();
+    program
+      .exitOverride()
+      .version(myVersion, '--revision');
+
+    expect(() => {
+      program.parse(['node', 'test', '--revision']);
+    }).toThrow(myVersion);
+  });
+
   test('when custom .version then helpInformation includes custom version help', () => {
     const myVersion = '1.2.3';
     const myVersionFlags = '-r, --revision';