feat: start re-working stress testing

tests/stress/cli.js

@@ -0,0 +1,59 @@
+const trimStart = (s, c) => {
+  let idx = 0
+  while (idx < s.length && s[idx] === c)
+    idx++
+  return idx > 0 ? s.substring(idx) : s
+}
+
+const optkey = (opt) => trimStart(opt, '-')
+
+const parse = (default_options, option_arities) => (args) => {
+  const positional = []
+  const parsed_options = {}
+
+  for (let i = 0; i < args.length;) {
+    const arg = args[i]
+    i++
+
+    const arity = option_arities[arg]
+    if (typeof(arity) === 'number') {
+      if (arity+i > args.length)
+        return [`${arg}: not enough arguments.`, parsed_options, positional]
+
+      const opt = optkey(arg)
+      switch (arity) {
+        case 0: parsed_options[opt] = true; break
+        case 1: parsed_options[opt] = args[i]; break
+        default: parsed_options[opt] = args.slice(i, i+arity); break
+      }
+      i += arity
+    } else {
+      positional.push(arg)
+    }
+  }
+
+  const options = Object.assign({}, default_options, parsed_options)
+  return [null, options, positional]
+}
+
+const help = ({ grammar, usage }) => () => {
+  if (usage) console.log(usage)
+  grammar.forEach(
+    ([optargs, optdesc, def]) => {
+      const deftext = def ? ` (default: ${def})` : ""
+      console.log(`\t${optargs.join(' ')}\t${optdesc}${deftext}`)
+    }
+  )
+}
+
+const CLI = ({ grammar, usage }) => {
+  const details = grammar.map(([[opt, ...optargs], optdesc, def]) => [opt, optargs.length, def])
+  const option_arities = Object.fromEntries(details.map(([opt, arity, _def]) => [opt, arity]))
+  const default_options = Object.fromEntries(details.map(([opt, _arity, def]) => [optkey(opt), def]))
+  return {
+    parse: parse(default_options, option_arities),
+    help: help({ grammar, usage }),
+  }
+}
+
+module.exports = CLI