CLI for parse-live-query-server (#2765)

* adds CLI for parse-live-query-server, adds ability to start parse-server with live-query server

* Don't crash when the message is badly formatted

src/cli/utils/parsers.js

@@ -0,0 +1,59 @@
+export function numberParser(key) {
+  return function(opt) {
+    opt = parseInt(opt);
+    if (!Number.isInteger(opt)) {
+      throw new Error(`The ${key} is invalid`);
+    }
+    return opt;
+  }
+}
+
+export function numberOrBoolParser(key) {
+  return function(opt) {
+    if (typeof opt === 'boolean') {
+      return opt;
+    }
+    return numberParser(key)(opt);
+  }
+}
+
+export function objectParser(opt) {
+  if (typeof opt == 'object') {
+    return opt;
+  }
+  return JSON.parse(opt)
+}
+
+export function arrayParser(opt) {
+  if (Array.isArray(opt)) {
+    return opt;
+  } else if (typeof opt === 'string') {
+    return opt.split(',');
+  } else {
+    throw new Error(`${opt} should be a comma separated string or an array`);
+  }
+}
+
+export function moduleOrObjectParser(opt) {
+  if (typeof opt == 'object')  {
+    return opt;
+  }
+  try {
+    return JSON.parse(opt);
+  } catch(e) {}
+  return opt;
+}
+
+export function booleanParser(opt) {
+  if (opt == true || opt == "true" || opt == "1") {
+    return true;
+  }
+  return false;
+}
+
+export function nullParser(opt) {
+  if (opt == 'null') {
+    return null;
+  }
+  return opt;
+}