refactor!: upgrade deps drop Node 6/8 (#71)

Author: Benjamin E. Coe

.github/workflows/ci.yaml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [6, 8, 10, 14]
+        node: [10, 12, 14]
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-node@v1

README.md

@@ -75,6 +75,11 @@ If you `coerce` in weird ways, things might not work correctly.
 `$ npm test`   
 `$ npm test -- --watch` during development
 
+## Supported Node.js Versions
+
+Libraries in this ecosystem make a best effort to track
+[Node.js' release schedule](https://nodejs.org/en/about/releases/). Here's [a
+post on why we think this is important](https://medium.com/the-node-js-collection/maintainers-should-consider-following-node-js-release-schedule-ab08ed4de71a).
 
 ## License
 

index.js

@@ -1,6 +1,5 @@
 'use strict';
 
-const yargs = require('yargs/yargs');
 const flatten = require('flat');
 const camelcase = require('camelcase');
 const decamelize = require('decamelize');
@@ -24,6 +23,40 @@ function keyToFlag(key) {
     return key.length === 1 ? `-${key}` : `--${key}`;
 }
 
+function parseCommand(cmd) {
+    const extraSpacesStrippedCommand = cmd.replace(/\s{2,}/g, ' ');
+    const splitCommand = extraSpacesStrippedCommand.split(/\s+(?![^[]*]|[^<]*>)/);
+    const bregex = /\.*[\][<>]/g;
+    const firstCommand = splitCommand.shift();
+
+    if (!firstCommand) { throw new Error(`No command found in: ${cmd}`); }
+    const parsedCommand = {
+        cmd: firstCommand.replace(bregex, ''),
+        demanded: [],
+        optional: [],
+    };
+
+    splitCommand.forEach((cmd, i) => {
+        let variadic = false;
+
+        cmd = cmd.replace(/\s/g, '');
+        if (/\.+[\]>]/.test(cmd) && i === splitCommand.length - 1) { variadic = true; }
+        if (/^\[/.test(cmd)) {
+            parsedCommand.optional.push({
+                cmd: cmd.replace(bregex, '').split('|'),
+                variadic,
+            });
+        } else {
+            parsedCommand.demanded.push({
+                cmd: cmd.replace(bregex, '').split('|'),
+                variadic,
+            });
+        }
+    });
+
+    return parsedCommand;
+}
+
 function unparseOption(key, value, unparsed) {
     if (typeof value === 'string') {
         unparsed.push(keyToFlag(key), value);
@@ -54,9 +87,7 @@ function unparsePositional(argv, options, unparsed) {
     // e.g.: build <first> <second> <rest...>
     if (options.command) {
         const { 0: cmd, index } = options.command.match(/[^<[]*/);
-        const { demanded, optional } = yargs()
-        .getCommandInstance()
-        .parseCommand(`foo ${options.command.substr(index + cmd.length)}`);
+        const { demanded, optional } = parseCommand(`foo ${options.command.substr(index + cmd.length)}`);
 
         // Push command (can be a deep command)
         unparsed.push(...cmd.trim().split(/\s+/));