feat: add user-defined schema and migrations (#7418)

src/SchemaMigrations/Migrations.js

@@ -0,0 +1,95 @@
+// @flow
+
+export type FieldValueType =
+  | 'String'
+  | 'Boolean'
+  | 'File'
+  | 'Number'
+  | 'Relation'
+  | 'Pointer'
+  | 'Date'
+  | 'GeoPoint'
+  | 'Polygon'
+  | 'Array'
+  | 'Object'
+  | 'ACL';
+
+export interface FieldType {
+  type: FieldValueType;
+  required?: boolean;
+  defaultValue?: mixed;
+  targetClass?: string;
+}
+
+type ClassNameType = '_User' | '_Role' | string;
+
+export interface ProtectedFieldsInterface {
+  [key: string]: string[];
+}
+
+export interface IndexInterface {
+  [key: string]: number;
+}
+
+export interface IndexesInterface {
+  [key: string]: IndexInterface;
+}
+
+export interface SchemaOptions {
+  definitions: JSONSchema[];
+  strict: ?boolean;
+  deleteExtraFields: ?boolean;
+  recreateModifiedFields: ?boolean;
+  lockSchemas: ?boolean;
+  /* Callback when server has started and before running schemas migration operations if schemas key provided */
+  beforeMigration: ?() => void | Promise<void>;
+  afterMigration: ?() => void | Promise<void>;
+}
+
+export type CLPOperation = 'find' | 'count' | 'get' | 'update' | 'create' | 'delete';
+// @Typescript 4.1+ // type CLPPermission = 'requiresAuthentication' | '*' |  `user:${string}` | `role:${string}`
+
+type CLPValue = { [key: string]: boolean };
+type CLPData = { [key: string]: CLPOperation[] };
+type CLPInterface = { [key: string]: CLPValue };
+
+export interface JSONSchema {
+  className: ClassNameType;
+  fields?: { [key: string]: FieldType };
+  indexes?: IndexesInterface;
+  classLevelPermissions?: {
+    find?: CLPValue,
+    count?: CLPValue,
+    get?: CLPValue,
+    update?: CLPValue,
+    create?: CLPValue,
+    delete?: CLPValue,
+    addField?: CLPValue,
+    protectedFields?: ProtectedFieldsInterface,
+  };
+}
+
+export class CLP {
+  static allow(perms: { [key: string]: CLPData }): CLPInterface {
+    const out = {};
+
+    for (const [perm, ops] of Object.entries(perms)) {
+      // @flow-disable-next Property `@@iterator` is missing in mixed [1] but exists in `$Iterable` [2].
+      for (const op of ops) {
+        out[op] = out[op] || {};
+        out[op][perm] = true;
+      }
+    }
+
+    return out;
+  }
+}
+
+export function makeSchema(className: ClassNameType, schema: JSONSchema): JSONSchema {
+  // This function solve two things:
+  // 1. It provides auto-completion to the users who are implementing schemas
+  // 2. It allows forward-compatible point in order to allow future changes to the internal structure of JSONSchema without affecting all the users
+  schema.className = className;
+
+  return schema;
+}