如何使用 Linq IndexedDB 插入对象

Question

我正在通过单元测试（通过Mocha）尝试使用 Linq2IndexedDB（v. 1.0.21），但我什至无法进行简单的插入工作。发生的情况（在 Google Chrome 下运行时）是在 Linq2IndexedDB.js 的第 1535 行引发内部异常：

Uncaught TypeError: Cannot read property 'version' of undefined

我的单元测试代码如下所示；基本上只有一个测试，“它可以添加对象”：

"use strict";

define(["db", "linq2indexeddb", "chai", "underscore", "stacktrace"], function (db, linq2indexeddb, chai, _,
    printStacktrace) {
    var should = chai.should();

    describe("db", function () {
        var _db;

        function fail(done, reason, err) {
            if (typeof reason === "string") {
                reason = new Error(reason);
            }
            if (!reason) {
                console.log(typeof done, typeof reason);
                reason = new Error("There's been an error, but no reason was supplied!");
                var st = printStacktrace({e: reason});
                console.log(st);
            }
            if (typeof done !== "function") {
                throw new Error("Was not supplied a function for 'done'!");
            }
            done(reason);
        }

        // Bind done as the first argument to the fail function
        function bindFail(done, reason) {
            if (typeof done !== "function") {
                throw new Error("done must be a function");
            }
            return _.partial(fail, done, reason);
        }

        beforeEach(function (done) {
            _db = linq2indexeddb("test", null, true);
            _db.deleteDatabase()
            .done(function () {
                _db.initialize()
                .done(done)
                .fail(bindFail(done, "Initializing database failed"));
            })
            .fail(bindFail(done, "Deleting database failed"));
        });

        it("can add objects", function (done) {
            console.log("Starting test");
            var refObj = {"key": "value"};
            _db.linq.from("store").insert(refObj, "Key")
            .done(function () {
                console.log("Added object successfully");
                done();
            })
            .fail(bindFail(done, "Inserting object failed"));
        });
    });
});

我在这里做错了什么，还是 Linq2IndexedDB 中的错误（或两者都有）？

我已经建立了一个相应的测试项目on Github，并配有Karma 配置，因此您可以轻松运行包含的测试。 Karma 配置假定您已安装 Chrome。

Answer 1

我发现了几个问题：

1. 我的 Linq2IndexedDB 工作位置错误，应该是：'/base/lib/Linq2IndexedDB.js'
2. 使用带外键的对象插入不起作用。

我最终在 IE 10 和 Chrome 上进行了插入工作，尽管我仍在为 PhantomJS 苦苦挣扎。为了让它在 Chrome 下工作，我必须明确指定我的模式，我怀疑这是由于 Linq2IndexedDB 中的一个错误。我的工作解决方案如下：

测试：

"use strict";

define(["db", "linq2indexeddb", "chai", "underscore", "stacktrace"], function (db, linq2indexeddb, chai, _,
    printStacktrace) {
    var should = chai.should();

    describe("db", function () {
        var _db;

        function fail(done, reason, err) {
            console.log("err:", err);
            if (typeof reason === "string") {
                reason = new Error(reason);
            }
            if (!reason) {
                console.log(typeof done, typeof reason);
                reason = new Error("There's been an error, but no reason was supplied!");
                var st = printStacktrace({e: reason});
                console.log(st);
            }
            if (typeof done !== "function") {
                throw new Error("Was not supplied a function for 'done'!");
            }
            done(reason);
        }

        // Bind done as the first argument to the fail function
        function bindFail(done, reason) {
            if (typeof done !== "function") {
                throw new Error("done must be a function");
            }
            return _.partial(fail, done, reason);
        }

        beforeEach(function (done) {
            // Linq2IndexedDB's web worker needs this URL
            linq2indexeddb.prototype.utilities.linq2indexedDBWorkerFileLocation = '/base/lib/Linq2IndexedDB.js'

            _db = new db.Database("test");

            console.log("Deleting database");
            _db.deleteDatabase()
            .done(function () {
                console.log("Initializing database");
                _db.initialize()
                .done(done)
                .fail(bindFail(done, "Initializing database failed"));
            })
            .fail(bindFail(done, "Deleting database failed"));
        });

        it("can add objects", function (done) {
            console.log("Starting test");
            var refObj = {"key": "value"};
            _db.insert(refObj)
            .done(function () {
                done();
            })
            .fail(bindFail(done, "Database insertion failed"));
        });
    });
});

实施：

define("db", ["linq2indexeddb"], function (linq2indexeddb) {
    function getDatabaseConfiguration() {
        var dbConfig = {
            version: 1
        };
        // NOTE: definition is an array of schemas, keyed by version;
        // this allows linq2indexedDb to do auto-schema-migrations, based upon the current dbConfig.version
        dbConfig.definition = [{
            version: 1,
            objectStores: [
            { name: "store", objectStoreOptions: { keyPath: 'key' } },
            ],
            defaultData: []
        },
        ];

        return dbConfig;
    }

    var module = {
        Database: function (name) {
            var self = this;

            self._db = linq2indexeddb(name, getDatabaseConfiguration());

            self.deleteDatabase = function () {
                return self._db.deleteDatabase();
            };

            self.initialize = function () {
                return self._db.initialize();
            };

            self.insert = function (data) {
                return self._db.linq.from("store").insert(data);
            };
        }
    };
    return module;
});

编辑： 它在 PhantomJS 下不起作用的原因是我在 Linq2IndexedDB 中启用了调试日志记录，出于某种原因，这似乎会在某些时候堵塞 Karma 的管道。关闭调试日志后，所有配置都有效。