Adds deprecator (#7303)

* adds deprecator

* un-fit

* added changelog entry

* some fixes

* un-fit

* removed deprecation definition

* changed deprecation log syntax according to Nodejs

src/Deprecator/Deprecations.js

@@ -0,0 +1,14 @@
+/**
+ * The deprecations.
+ *
+ * Add deprecations to the array using the following keys:
+ * - `optionKey`: The option key incl. its path, e.g. `security.enableCheck`.
+ * - `envKey`: The environment key, e.g. `PARSE_SERVER_SECURITY`.
+ * - `changeNewKey`: Set the new key name if the current key will be replaced,
+ * or set to an empty string if the current key will be removed without replacement.
+ * - `changeNewDefault`: Set the new default value if the key's default value
+ * will change in a future version.
+ *
+ * If there are no deprecations this must return an empty array anyway.
+ */
+module.exports = [];

src/Deprecator/Deprecator.js

@@ -0,0 +1,71 @@
+import logger from '../logger';
+import Deprecations from './Deprecations';
+
+/**
+ * The deprecator class.
+ */
+class Deprecator {
+  /**
+   * Scans the Parse Server for deprecated options.
+   * This needs to be called before setting option defaults, otherwise it
+   * becomes indistinguishable whether an option has been set manually or
+   * by default.
+   * @param {any} options The Parse Server options.
+   */
+  static scanParseServerOptions(options) {
+    // Scan for deprecations
+    for (const deprecation of Deprecator._getDeprecations()) {
+      // Get deprecation properties
+      const optionKey = deprecation.optionKey;
+      const changeNewDefault = deprecation.changeNewDefault;
+
+      // If default will change, only throw a warning if option is not set
+      if (changeNewDefault != null && options[optionKey] == null) {
+        Deprecator._log({ optionKey, changeNewDefault });
+      }
+    }
+  }
+
+  /**
+   * Returns the deprecation definitions.
+   * @returns {Array<Object>} The deprecations.
+   */
+  static _getDeprecations() {
+    return Deprecations;
+  }
+
+  /**
+   * Logs a deprecation warning for a Parse Server option.
+   * @param {String} optionKey The option key incl. its path, e.g. `security.enableCheck`.
+   * @param {String} envKey The environment key, e.g. `PARSE_SERVER_SECURITY`.
+   * @param {String} changeNewKey Set the new key name if the current key will be replaced,
+   * or set to an empty string if the current key will be removed without replacement.
+   * @param {String} changeNewDefault Set the new default value if the key's default value
+   * will change in a future version.
+   * @param {String} [solution] The instruction to resolve this deprecation warning. This
+   * message must not include the warning that the parameter is deprecated, that is
+   * automatically added to the message. It should only contain the instruction on how
+   * to resolve this warning.
+   */
+  static _log({ optionKey, envKey, changeNewKey, changeNewDefault, solution }) {
+    const type = optionKey ? 'option' : 'environment key';
+    const key = optionKey ? optionKey : envKey;
+    const keyAction =
+      changeNewKey == null
+        ? undefined
+        : changeNewKey.length > 0
+          ? `renamed to '${changeNewKey}'`
+          : `removed`;
+
+    // Compose message
+    let output = `DeprecationWarning: The Parse Server ${type} '${key}' `;
+    output += changeNewKey ? `is deprecated and will be ${keyAction} in a future version.` : '';
+    output += changeNewDefault
+      ? `default will change to '${changeNewDefault}' in a future version.`
+      : '';
+    output += solution ? ` ${solution}` : '';
+    logger.warn(output);
+  }
+}
+
+module.exports = Deprecator;

src/ParseServer.js

@@ -43,6 +43,7 @@ import * as controllers from './Controllers';
 import { ParseGraphQLServer } from './GraphQL/ParseGraphQLServer';
 import { SecurityRouter } from './Routers/SecurityRouter';
 import CheckRunner from './Security/CheckRunner';
+import Deprecator from './Deprecator/Deprecator';
 
 // Mutate the Parse object to add the Cloud Code handlers
 addParseCloud();
@@ -55,6 +56,9 @@ class ParseServer {
    * @param {ParseServerOptions} options the parse server initialization options
    */
   constructor(options: ParseServerOptions) {
+    // Scan for deprecated Parse Server options
+    Deprecator.scanParseServerOptions(options);
+    // Set option defaults
     injectDefaults(options);
     const {
       appId = requiredParameter('You must provide an appId!'),

src/cli/utils/commander.js

@@ -1,6 +1,8 @@
 /* eslint-disable no-console */
 import { Command } from 'commander';
 import path from 'path';
+import Deprecator from '../../Deprecator/Deprecator';
+
 let _definitions;
 let _reverseDefinitions;
 let _defaults;
@@ -40,7 +42,7 @@ Command.prototype.loadDefinitions = function (definitions) {
   }, {});
 
   _defaults = Object.keys(definitions).reduce((defs, opt) => {
-    if (_definitions[opt].default) {
+    if (_definitions[opt].default !== undefined) {
       defs[opt] = _definitions[opt].default;
     }
     return defs;
@@ -119,6 +121,8 @@ Command.prototype.parse = function (args, env) {
   this.setValuesIfNeeded(envOptions);
   // Load from file to override
   this.setValuesIfNeeded(fromFile);
+  // Scan for deprecated Parse Server options
+  Deprecator.scanParseServerOptions(this);
   // Last set the defaults
   this.setValuesIfNeeded(_defaults);
 };