WIP pass the failed tests.

server/src/lib/KnexFactory/index.js

@@ -0,0 +1,55 @@
+const { extend, isFunction, isObject } = require('lodash');
+
+export default class KnexFactory {
+
+  constructor(knex) {
+    this.knex = knex;
+
+    this.factories = [];
+  }
+
+  define(name, tableName, defaultAttributes) {
+    this.factories[name] = { tableName, defaultAttributes };
+  }
+
+  async build(factoryName, attributes) {
+    const factory = this.factories[factoryName];
+
+    if (!factory) {
+      throw `Unkown factory: ${factoryName}`;
+    }
+    let { defaultAttributes } = factory;
+    const insertData = {};
+    
+    if( 'function' === typeof defaultAttributes) {
+      defaultAttributes = await defaultAttributes();
+    }
+    extend(insertData, defaultAttributes, attributes);
+
+    for (let k in insertData) {
+      const v = insertData[k];
+
+      if (isFunction(v)) {
+        insertData[k] = await v();
+      } else {
+        insertData[k] = await v;
+      }
+      if (isObject(insertData[k]) && insertData[k].id) {
+        insertData[k] = insertData[k].id;
+      }
+    };
+
+    return insertData;
+  }
+
+  async create(factoryName, attributes) {
+    const factory = this.factories[factoryName];
+    const insertData = await this.build(factoryName, attributes);
+    const { tableName } = factory;
+
+    const [id] = await this.knex(tableName).insert(insertData);
+    const record = await this.knex(tableName).where({ id }).first();
+
+    return record;
+  }
+}