Initial work on parseArgs (#1)

* starting with dash dash

* arg work

* use strict in test file

Author: joesepi

index.js

@@ -0,0 +1,60 @@
+'use strict';
+
+const parseArgs = (
+  argv = process.argv.slice(require.main ? 2 : 1),
+  options = {}
+) => {
+  if (typeof options !== 'object' || options === null) {
+    throw new Error('Whoops!')
+  }
+
+  let result = {
+    args: {},
+    values: {},
+    positionals: []
+  }
+
+  let pos = 0
+  while (pos < argv.length) {
+    let arg = argv[pos]
+
+    if (arg.startsWith('-')) {
+      // Everything after a bare '--' is considered a positional argument
+      // and is returned verbatim
+      if (arg === '--') {
+        result.positionals.push(...argv.slice(++pos))
+
+        return result
+      }
+      // look for shortcodes: -fXzy
+      else if (arg.charAt(1) !== '-') {
+        throw new Error('What are we doing with shortcodes!?!')
+      }
+
+      // Any number of leading dashes are allowed
+      // remove all leading dashes
+      arg = arg.replace(/^-+/, '')
+
+      if (arg.includes('=')) {
+        const argParts = arg.split('=')
+
+        result.args[argParts[0]] = true
+        if (options.withValue) {
+          result.values[argParts[0]] = argParts[1]
+        }
+      }
+      else {
+        result.args[arg] = true
+
+      }
+    }
+
+    pos++
+  }
+
+  return result
+}
+
+module.exports = {
+  parseArgs
+}