Add ability to specify command description to argparse

packages/argparse/src/argparse.test.ts

@@ -159,7 +159,7 @@ describe('argparse', () => {
           type: 'string[]',
         },
         help: arg('boolean'),
-      }, exit, log)
+      }, '', exit, log)
       expect(parse([CMD]).value).toEqual([])
       expect(parse([CMD, '--value', 'one']).value).toEqual(['one'])
       parse([CMD, '--help'])
@@ -182,7 +182,7 @@ describe('argparse', () => {
           alias: 'o',
         },
         help: arg('boolean'),
-      }, exit, log)
+      }, '', exit, log)
       expect(parse([CMD]).value).toEqual([])
       expect(parse([CMD, '--value', 'a', 'b', '--other', '-o', '3'])).toEqual({
         value: ['a', 'b', '--other'],
@@ -204,7 +204,7 @@ describe('argparse', () => {
         value: arg('string[]', {n: '+', required: true}),
         other: arg('number'),
         help: arg('boolean'),
-      }, exit, log)
+      }, '', exit, log)
       expect(() => parse([CMD])).toThrowError(/Missing required args: value/)
       expect(parse([CMD, '--value', 'a', '--other', '3'])).toEqual({
         value: ['a', '--other', '3'],
@@ -232,7 +232,7 @@ describe('argparse', () => {
         value: arg('string[]', {n: '*', required: true, positional: true}),
         other: arg('number'),
         help: arg('boolean'),
-      }, exit, log)
+      }, '', exit, log)
       expect(parse([CMD, 'a', 'b']).value).toEqual(['a', 'b'])
       expect(() => parse([CMD, '--other', '3']).value)
       .toThrowError(/Missing.*: value/)
@@ -272,7 +272,7 @@ describe('argparse', () => {
           type: 'number',
           positional: true,
         },
-      }, exit, log)
+      }, '', exit, log)
       expect(parse([CMD]).a).toBe(NaN)
       expect(parse([CMD, '12']).a).toBe(12)
       parse([CMD, '--help'])
@@ -352,13 +352,15 @@ Positional arguments:
         two: arg('number'),
         three: arg('boolean'),
         help: arg('boolean'),
-      }, exit, log)
+      }, 'This command does something', exit, log)
       expect(exit.mock.calls.length).toBe(0)
       parse([CMD, '--help'])
       expect(exit.mock.calls.length).toBe(1)
       expect(log.mock.calls[0][0]).toEqual([
         `${CMD} [OPTIONS]`,
         '',
+        'This command does something',
+        '',
         'Options:',
         '      --one string',
         '      --two number',
@@ -383,7 +385,7 @@ Positional arguments:
           positional: true,
         }),
         help: arg('boolean'),
-      }, exit, log)
+      }, '', exit, log)
       expect(exit.mock.calls.length).toBe(0)
       parse([CMD, '--help'])
       expect(exit.mock.calls.length).toBe(1)

packages/argparse/src/argparse.ts

@@ -150,14 +150,14 @@ function checkChoice<T>(argument: string, choice: T, choices?: T[]) {
   }
 }
 
-export function padRight(str: string, chars: number) {
+function padRight(str: string, chars: number) {
   while (str.length < chars) {
     str += ' '
   }
   return str
 }
 
-export function help(command: string, config: IArgsConfig) {
+function help(command: string, config: IArgsConfig, desc: string = '') {
   const keys = Object.keys(config)
 
   function getArrayHelp(
@@ -257,7 +257,7 @@ export function help(command: string, config: IArgsConfig) {
   .filter(k => k.length)
   .join(' ')
 
-  return [commandHelp, positionalHelp, optionsHelp]
+  return [commandHelp, desc, positionalHelp, optionsHelp]
   .filter(h => h.length)
   .join('\n\n')
 }
@@ -274,6 +274,7 @@ export function arg<T extends TArgTypeName>(
 
 export function argparse<T extends IArgsConfig>(
   config: T,
+  description: string = '',
   exit: () => void = () => process.exit(),
   /* tslint:disable-next-line */
   log: (message: string) => void = console.log.bind(console),
@@ -360,7 +361,7 @@ export function argparse<T extends IArgsConfig>(
           : getNextPositional(argument)
         const argConfig = config[argName]
         if (!isPositional && argName === 'help') {
-          log(help(command, config))
+          log(help(command, config, description))
           exit()
           // should never reach this in real life
           return null as any