[PERF] validator: Lazy load dependencies

- Only require modules / dependencies when needed
- Create singleton validator instance only on first usage

lib/validation/validator.js

@@ -1,11 +1,7 @@
-const Ajv = require("ajv");
-const ajvErrors = require("ajv-errors");
 const path = require("path");
 const {promisify} = require("util");
 const readFile = promisify(require("fs").readFile);
 
-const ValidationError = require("./ValidationError");
-
 async function loadSchema(schemaPath) {
  const filePath = schemaPath.replace("http://ui5.sap/schema/", "");
  const schemaFile = await readFile(path.join(__dirname, "schema", filePath), {encoding: "utf8"});
@@ -18,11 +14,13 @@ async function loadSchema(schemaPath) {
  */
 class Validator {
  constructor() {
+ const Ajv = require("ajv");
  this.ajv = new Ajv({
  allErrors: true,
  jsonPointers: true,
  loadSchema
  });
+ const ajvErrors = require("ajv-errors");
  ajvErrors(this.ajv);
  }
 
@@ -41,6 +39,7 @@ class Validator {
  const fnValidate = await this._compileSchema();
  const valid = fnValidate(config);
  if (!valid) {
+ const ValidationError = require("./ValidationError");
  throw new ValidationError({
  errors: fnValidate.errors,
  schema: fnValidate.schema,
@@ -51,7 +50,7 @@ class Validator {
  }
 }
 
-const validator = new Validator();
+let validator;
 
 /**
  * @public
@@ -77,6 +76,9 @@ module.exports = {
  * @public
  */
  validate: async (options) => {
+ if (!validator) {
+ validator = new Validator();
+ }
  await validator.validate(options);
  },
  _Validator: Validator // For testing only