Add relationsChecker

server/utils/relationsChecker.js

@@ -0,0 +1,73 @@
+const _ = require('lodash');
+const Promise = require('bluebird');
+const db = require('../db');
+
+module.exports = {
+  hierarchy: ['users', 'boards', 'lists', 'cards'],
+
+  check(data) {
+    const entities = _.keys(data);
+    const higherEntity = this._getHigherEntity(entities);
+    const lowerEntity = _.without(entities, higherEntity)[0];
+    const sql = this._getSql(higherEntity, lowerEntity, _.values(data));
+    return db.result(sql)
+      .then(result => result.rowCount >= 1);
+  },
+
+  _getSql(higherEntity, lowerEntity, values) {
+    const joinSql = this._getJoinSql(higherEntity, lowerEntity);
+    const idsNames = this._getIdsNames([higherEntity, lowerEntity]);
+    const higherEntityChild = this._getChildEntity(higherEntity);
+    const table = `${higherEntity}_${higherEntityChild}`;
+    return `SELECT * FROM ${table} AS p ${joinSql}` +
+    `WHERE ${idsNames[0]} = '${values[0]}' AND ${idsNames[1]} = '${values[1]}'`;
+  },
+
+  _getJoinSql(higherEntity, lowerEntity) {
+    const innerEntities = this._getInnerEntities(higherEntity, lowerEntity);
+    const idsNames = this._getIdsNames(innerEntities);
+    return _.reduce(innerEntities, (acc, entity, i) => {
+      const nextEntity = innerEntities[i + 1] || lowerEntity;
+      const t0 = i === 0 ? 'p' : `t${i}`;
+      const t = `t${i + 1}`;
+      const idName = idsNames[i];
+      return acc + `JOIN ${entity}_${nextEntity} AS ${t} ON (${t0}.${idName} = ${t}.${idName})`;
+    }, '');
+  },
+
+  _getIdsNames(entities) {
+    return entities.map(entity => {
+      return entity.slice(0, -1) + '_id';
+    });
+  },
+
+  _getHigherEntity(entities) {
+    if (entities.filter(e => typeof e !== 'string').length) {
+      throw new Error('All entities must be a strings');
+    }
+
+    const i0 = this._getIndexInHierarchy(entities[0]);
+    const i1 = this._getIndexInHierarchy(entities[1]);
+
+    return i0 < i1 ? entities[0] : entities[1];
+  },
+
+  _getInnerEntities(higherEntity, lowerEntity) {
+    const highInd = this._getIndexInHierarchy(higherEntity);
+    const lowInd = this._getIndexInHierarchy(lowerEntity);
+
+    return this.hierarchy.filter((entity, i) => {
+      return i > highInd && i < lowInd;
+    });
+  },
+
+  _getChildEntity(entity) {
+    const index = this._getIndexInHierarchy(entity);
+    const child = this.hierarchy[index + 1];
+    return child || null;
+  },
+
+  _getIndexInHierarchy(entity) {
+    return this.hierarchy.indexOf(entity);
+  },
+};

test/server/utils/relationsChecker.spec.js

@@ -0,0 +1,155 @@
+import { assert } from 'chai';
+import { recreateTables } from '../helpers';
+import db from 'server/db';
+import relationsChecker from 'server/utils/relationsChecker';
+
+const initialHierarchy = relationsChecker.hierarchy;
+
+describe('relationsChecker', () => {
+  before(() => {
+    relationsChecker.hierarchy = ['users', 'boards', 'lists', 'cards'];
+  });
+
+  after(() => {
+    relationsChecker.hierarchy = initialHierarchy;
+  });
+
+  describe('check', () => {
+    beforeEach(() => {
+      return recreateTables()
+      .then(() => {
+        return db.none(`
+          INSERT INTO users (id, username, email, hash, salt)
+          VALUES ('1', 'test', '[email protected]', 'hash', 'salt');
+          INSERT INTO boards (id, title)
+          VALUES ('7', 'board 7'), ('10', 'board 10'), ('15', 'board 15');
+          INSERT INTO users_boards
+          VALUES ('1', '10'), ('1', '15');
+          INSERT INTO lists (id, title)
+          VALUES ('4', 'list 4'), ('5', 'list 5');
+          INSERT INTO boards_lists
+          VALUES ('15', '4');
+          `);
+        });
+      });
+
+      it('should resolve true if entries are related', () => {
+        return relationsChecker.check({
+          users: '1',
+          lists: '4'
+        }).then(result => assert.isTrue(result));
+      });
+
+      it('should resolve false if entries are not related', () => {
+        return relationsChecker.check({
+          users: '1',
+          lists: '5'
+        }).then(result => assert.isFalse(result));
+      });
+
+      it('should resolve false if higher entry does not exist', () => {
+        return relationsChecker.check({
+          users: '27',
+          lists: '5'
+        }).then(result => assert.isFalse(result));
+      });
+
+      it('should resolve false if lower entry does not exist', () => {
+        return relationsChecker.check({
+          users: '1',
+          lists: '50'
+        }).then(result => assert.isFalse(result));
+      });
+    });
+
+    describe('_getHigherEntity', () => {
+      it('should return higher entity name', () => {
+        const higher1 = relationsChecker._getHigherEntity(['cards', 'users']);
+        assert.equal(higher1, 'users');
+        const higher2 = relationsChecker._getHigherEntity(['cards', 'boards']);
+        assert.equal(higher2, 'boards');
+      });
+    });
+
+    describe('_getIndexInHierarchy', () => {
+      it('should return index of entity in hierarchy', () => {
+        const index = relationsChecker._getIndexInHierarchy('lists');
+        assert.equal(index, 2);
+      });
+    });
+
+    describe('_getChildEntity', () => {
+      it('should return next entity in hierarchy', () => {
+        const childEntity = relationsChecker._getChildEntity('lists');
+        assert.equal(childEntity, 'cards');
+      });
+
+      it('should return null, if entity has no children', () => {
+        const childEntity = relationsChecker._getChildEntity('cards');
+        assert.isNull(childEntity);
+      });
+    });
+
+    describe('_getInnerEntities', () => {
+      it('should return array entities between two given entities', () => {
+        const insideEntities = relationsChecker._getInnerEntities('users', 'cards');
+        assert.deepEqual(insideEntities, ['boards', 'lists']);
+      });
+
+      it('should return [], if entities are siblings', () => {
+        const insideEntities = relationsChecker._getInnerEntities('lists', 'cards');
+        assert.deepEqual(insideEntities, []);
+      });
+    });
+
+    describe('_getIdsNames', () => {
+      it('should return ids columns names in relations table', () => {
+        const idsNames = relationsChecker._getIdsNames(['boards', 'lists', 'cards']);
+        assert.deepEqual(idsNames, ['board_id', 'list_id', 'card_id']);
+      });
+    });
+
+    describe('_getJoinSql', () => {
+      it('should return sql with join', () => {
+        const sql = relationsChecker._getJoinSql('users', 'cards', ['user_id', 'card_id']);
+        assert.equal(sql,
+          'JOIN boards_lists AS t1 ON (p.board_id = t1.board_id)' +
+          'JOIN lists_cards AS t2 ON (t1.list_id = t2.list_id)'
+        );
+      });
+
+      it('should return empty string, when given entities are siblings', () => {
+        const sql = relationsChecker._getJoinSql('users', 'boards', ['user_id', 'board_id']);
+        assert.equal(sql, '');
+      });
+    });
+
+    describe('_getSql', () => {
+      it('should return sql for checking relations where between entities are 2 or more entities', () => {
+        const sql = relationsChecker._getSql('users', 'cards', [10, 5]);
+        assert.equal(sql,
+          "SELECT * FROM users_boards AS p " +
+          "JOIN boards_lists AS t1 ON (p.board_id = t1.board_id)" +
+          "JOIN lists_cards AS t2 ON (t1.list_id = t2.list_id)" +
+          "WHERE user_id = '10' AND card_id = '5'"
+        );
+      });
+
+      it('should return sql for checking relations where between entities 1 entity', () => {
+        const sql = relationsChecker._getSql('users', 'lists', [10, 5]);
+        assert.equal(sql,
+          "SELECT * FROM users_boards AS p " +
+          "JOIN boards_lists AS t1 ON (p.board_id = t1.board_id)" +
+          "WHERE user_id = '10' AND list_id = '5'"
+        );
+      });
+
+      it('should return sql for checking relations where entities are siblings', () => {
+        const sql = relationsChecker._getSql('users', 'boards', [10, 5]);
+        assert.equal(sql,
+          "SELECT * FROM users_boards AS p " +
+          "WHERE user_id = '10' AND board_id = '5'"
+        );
+      });
+    });
+  });