feat(string-utils): export looksLikeNumber helper

browser.js

@@ -2,7 +2,7 @@
 // specific libraries, such as "path".
 //
 // TODO: figure out reasonable web equivalents for "resolve", "normalize", etc.
-import { camelCase, decamelize } from './build/lib/string-utils.js'
+import { camelCase, decamelize, looksLikeNumber } from './build/lib/string-utils.js'
 import { YargsParser } from './build/lib/yargs-parser.js'
 const parser = new YargsParser({
   cwd: () => { return '' },
@@ -24,5 +24,6 @@ yargsParser.detailed = function (args, opts) {
 }
 yargsParser.camelCase = camelCase
 yargsParser.decamelize = decamelize
+yargsParser.looksLikeNumber = looksLikeNumber
 
 export default yargsParser

deno.ts

@@ -3,7 +3,7 @@
 //
 // TODO: find reasonable replacement for require logic.
 import * as path from 'https://deno.land/std/path/mod.ts'
-import { camelCase, decamelize } from './build/lib/string-utils.js'
+import { camelCase, decamelize, looksLikeNumber } from './build/lib/string-utils.js'
 import { YargsParser } from './build/lib/yargs-parser.js'
 import { Arguments, ArgsInput, Parser, Options, DetailedArguments } from './build/lib/yargs-parser-types.d.ts'
 
@@ -33,5 +33,6 @@ yargsParser.detailed = function (args: ArgsInput, opts?: Partial<Options>): Deta
 }
 yargsParser.camelCase = camelCase
 yargsParser.decamelize = decamelize
+yargsParser.looksLikeNumber = looksLikeNumber
 
 export default yargsParser

lib/index.ts

@@ -4,7 +4,7 @@ import { format } from 'util'
 import { readFileSync } from 'fs'
 import { normalize, resolve } from 'path'
 import { ArgsInput, Arguments, Parser, Options, DetailedArguments } from './yargs-parser-types.js'
-import { camelCase, decamelize } from './string-utils.js'
+import { camelCase, decamelize, looksLikeNumber } from './string-utils.js'
 import { YargsParser } from './yargs-parser.js'
 
 // See https://github.com/yargs/yargs-parser#supported-nodejs-versions for our
@@ -49,4 +49,5 @@ yargsParser.detailed = function (args: ArgsInput, opts?: Partial<Options>): Deta
 }
 yargsParser.camelCase = camelCase
 yargsParser.decamelize = decamelize
+yargsParser.looksLikeNumber = looksLikeNumber
 export default yargsParser

lib/string-utils.ts

@@ -38,3 +38,14 @@ export function decamelize (str: string, joinString?: string): string {
   }
   return notCamelcase
 }
+
+export function looksLikeNumber (x: null | undefined | number | string): boolean {
+  if (x === null || x === undefined) return false
+  // if loaded from config, may already be a number.
+  if (typeof x === 'number') return true
+  // hexadecimal.
+  if (/^0x[0-9a-f]+$/i.test(x)) return true
+  // don't treat 0123 as a number; as it drops the leading '0'.
+  if (x.length > 1 && x[0] === '0') return false
+  return /^[-]?(?:\d+(?:\.\d*)?|\.\d+)(e[-+]?\d+)?$/.test(x)
+}

lib/yargs-parser-types.ts

@@ -131,6 +131,7 @@ export interface Parser {
   detailed(args: ArgsInput, opts?: Partial<Options>): DetailedArguments;
   camelCase(str: string): string;
   decamelize(str: string, joinString?: string): string;
+  looksLikeNumber(x: null | undefined | number | string): boolean;
 }
 
 export type StringFlag = Dictionary<string[]>;

lib/yargs-parser.ts

@@ -22,7 +22,7 @@ import type {
   YargsParserMixin
 } from './yargs-parser-types.js'
 import type { Dictionary, ValueOf } from './common-types.js'
-import { camelCase, decamelize } from './string-utils.js'
+import { camelCase, decamelize, looksLikeNumber } from './string-utils.js'
 
 let mixin: YargsParserMixin
 export class YargsParser {
@@ -621,7 +621,7 @@ export class YargsParser {
     function maybeCoerceNumber (key: string, value: string | number | null | undefined) {
       if (!configuration['parse-positional-numbers'] && key === '_') return value
       if (!checkAllAliases(key, flags.strings) && !checkAllAliases(key, flags.bools) && !Array.isArray(value)) {
-        const shouldCoerceNumber = isNumber(value) && configuration['parse-numbers'] && (
+        const shouldCoerceNumber = looksLikeNumber(value) && configuration['parse-numbers'] && (
           Number.isSafeInteger(Math.floor(parseFloat(`${value}`)))
         )
         if (shouldCoerceNumber || (!isUndefined(value) && checkAllAliases(key, flags.numbers))) {
@@ -1004,17 +1004,6 @@ export class YargsParser {
       return type
     }
 
-    function isNumber (x: null | undefined | number | string): boolean {
-      if (x === null || x === undefined) return false
-      // if loaded from config, may already be a number.
-      if (typeof x === 'number') return true
-      // hexadecimal.
-      if (/^0x[0-9a-f]+$/i.test(x)) return true
-      // don't treat 0123 as a number; as it drops the leading '0'.
-      if (x.length > 1 && x[0] === '0') return false
-      return /^[-]?(?:\d+(?:\.\d*)?|\.\d+)(e[-+]?\d+)?$/.test(x)
-    }
-
     function isUndefined (num: any): num is undefined {
       return num === undefined
     }

test/deno/yargs-test.ts

@@ -54,3 +54,12 @@ Deno.test('convert hyphenated string to camelcase', () => {
 Deno.test('convert camelcase string to hyphenated', () => {
   assertEquals(parser.decamelize('helloWorld'), 'hello-world')
 })
+
+Deno.test('it detects strings that could be parsed as numbers', () => {
+  assertEquals(parser.looksLikeNumber('3293'), true)
+  assertEquals(parser.looksLikeNumber('0x10'), true)
+  assertEquals(parser.looksLikeNumber('0x10'), true)
+
+  assertEquals(parser.looksLikeNumber('0100'), false)
+  assertEquals(parser.looksLikeNumber('apple'), false)
+})

test/string-utils.cjs

@@ -1,20 +1,30 @@
 /* global describe, it */
 
-const { expect } = require('chai')
-const { camelCase, decamelize } = require('../build/index.cjs')
+const { strictEqual } = require('assert')
+const { camelCase, decamelize, looksLikeNumber } = require('../build/index.cjs')
 
 describe('string-utils', function () {
   describe('camelCase', () => {
     it('converts string with hypen in middle to camel case', () => {
-      expect(camelCase('hello-world')).to.equal('helloWorld')
+      strictEqual(camelCase('hello-world'), 'helloWorld')
     })
     it('removes leading hyphens', () => {
-      expect(camelCase('-goodnight-moon')).to.equal('goodnightMoon')
+      strictEqual(camelCase('-goodnight-moon'), 'goodnightMoon')
     })
   })
   describe('decamelize', () => {
     it('adds hyphens back to camelcase string', () => {
-      expect(decamelize('helloWorld')).to.equal('hello-world')
+      strictEqual(decamelize('helloWorld'), 'hello-world')
+    })
+  })
+  describe('looksLikeNumber', () => {
+    it('it detects strings that could be parsed as numbers', () => {
+      strictEqual(looksLikeNumber('3293'), true)
+      strictEqual(looksLikeNumber('0x10'), true)
+      strictEqual(looksLikeNumber('0x10'), true)
+
+      strictEqual(looksLikeNumber('0100'), false)
+      strictEqual(looksLikeNumber('apple'), false)
     })
   })
 })