implemented /help route

src/routes/validate/help.ts

@@ -0,0 +1,34 @@
+import Joi from 'joi';
+import globals from '../../globals';
+
+export default class HelpValidate {
+  private static help = {
+    text: Joi.string()
+      .allow('')
+      .max(8192),
+
+    level: Joi.string()
+      .valid('none', ...Object.values(globals.levels))
+  }
+
+  static input (data) {
+    return Joi.object({
+      text: this.help.text.required(),
+      level: this.help.level.required()
+    }).validate(data);
+  }
+
+  static output (data) {
+    const {value, error} = Joi.object({
+      text: this.help.text,
+      level: this.help.level
+    }).validate(data, {stripUnknown: true});
+    return error !== undefined? null : value;
+  }
+
+  static params(data) {
+    return Joi.object({
+      key: Joi.string().min(1).max(128)
+    }).validate(data);
+  }
+}