cli: extract option splitter and use it for --compiler (#958)

resolves #746

src/cli/configuration_builder.js

@@ -3,6 +3,7 @@ import ArgvParser from './argv_parser'
 import fs from 'mz/fs'
 import path from 'path'
 import PathExpander from './path_expander'
+import OptionSplitter from './option_splitter'
 import Promise from 'bluebird'
 
 export default class ConfigurationBuilder {
@@ -95,17 +96,9 @@ export default class ConfigurationBuilder {
 
   getFormats() {
     const mapping = { '': 'progress' }
-    this.options.format.forEach(function(format) {
-      let type = format
-      let outputTo = ''
-      const parts = format.split(/([^A-Z]):([^\\])/)
-
-      if (parts.length > 1) {
-        type = parts.slice(0, 2).join('')
-        outputTo = parts.slice(2).join('')
-      }
-
-      mapping[outputTo] = type
+    this.options.format.forEach(format => {
+      const [type, outputTo] = OptionSplitter.split(format)
+      mapping[outputTo || ''] = type
     })
     return _.map(mapping, function(type, outputTo) {
       return { outputTo, type }
@@ -139,9 +132,9 @@ export default class ConfigurationBuilder {
   async expandSupportCodePaths(supportCodePaths) {
     const extensions = ['js']
     this.options.compiler.forEach(compiler => {
-      const parts = compiler.split(':')
-      extensions.push(parts[0])
-      require(parts[1])
+      const [extension, module] = OptionSplitter.split(compiler)
+      extensions.push(extension)
+      require(module)
     })
     return await this.pathExpander.expandPathsWithExtensions(
       supportCodePaths,

src/cli/option_splitter.js

@@ -0,0 +1,17 @@
+export default class OptionSplitter {
+  static split(option) {
+    const parts = option.split(/([^A-Z]):(?!\\)/)
+
+    return parts.reduce((memo, part, i) => {
+      if (partNeedsRecombined(i)) {
+        memo.push(parts.slice(i, i + 2).join(''))
+      }
+
+      return memo
+    }, [])
+  }
+}
+
+function partNeedsRecombined(i) {
+  return i % 2 === 0
+}

src/cli/option_splitter_spec.js

@@ -0,0 +1,52 @@
+import OptionSplitter from './option_splitter'
+
+describe('OptionSplitter', function() {
+  const examples = [
+    {
+      description: "doesn't split when nothing to split on",
+      input: '../custom/formatter',
+      output: ['../custom/formatter']
+    },
+    {
+      description: 'splits relative unix paths',
+      input: '../custom/formatter:../formatter/output.txt',
+      output: ['../custom/formatter', '../formatter/output.txt']
+    },
+    {
+      description: 'splits absolute unix paths',
+      input: '/custom/formatter:/formatter/output.txt',
+      output: ['/custom/formatter', '/formatter/output.txt']
+    },
+    {
+      description: 'splits absolute windows paths',
+      input: 'C:\\custom\\formatter:C:\\formatter\\output.txt',
+      output: ['C:\\custom\\formatter', 'C:\\formatter\\output.txt']
+    },
+    {
+      description: 'does not split a single absolute windows paths',
+      input: 'C:\\custom\\formatter',
+      output: ['C:\\custom\\formatter']
+    },
+    {
+      description: 'splits extensions and modules',
+      input: 'ts:typescript',
+      output: ['ts', 'typescript']
+    },
+    {
+      description: 'splits extension and module with an absolute windows path',
+      input: 'ts:C:/typescript',
+      output: ['ts', 'C:/typescript']
+    },
+    {
+      description: 'splits more than 2 parts',
+      input: 'part1:part2:part3',
+      output: ['part1', 'part2', 'part3']
+    }
+  ]
+
+  examples.forEach(({ description, input, output }) => {
+    it(description, function() {
+      expect(OptionSplitter.split(input)).to.eql(output)
+    })
+  })
+})