流星启动不了。ejson.js中的“在严格模式之外尚不支持块范围的声明(let、const、function、class)”

Question

我是Meteor的新手，只想安装和运行一个新的应用程序。上周五我的工作正常，但今天不得不重新安装，不能再运行应用程序了。

安装一直是一个挑战。尝试在Windows上安装，但发现安装程序不起作用。已求助于提取tar.gz文件。此外，由于公司限制，必须将其安装到备用位置( %LocalAppData%中的默认值由策略锁定)。但是，正如我所说的，这在上周是有效的，但今天无法使其正常工作。团队中的其他人也在本周开始看到这一点。当第一次运行meteor时，它会更新到meteor-tool到1.5.2.2，然后更新各种包。ejson包就是其中之一，并被更新到1.0.14。如果我运行meteor update，它会告诉我项目已经是1.5.2.2了。(最新)和顶级依赖项的最新兼容版本。我该如何解决这个问题？谢谢!

控制台输出：

C:\dev\R&D\meteor\meteor-test>meteor
[[[[[ C:\dev\R&D\meteor\meteor-test ]]]]]

=> Started proxy.
=> Started MongoDB.
W20171020-14:19:35.920(-5)? (STDERR) C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\packages\ejson.js:749
W20171020-14:19:36.013(-5)? (STDERR)       for (let i = 0; i < length; i += 1) {
W20171020-14:19:36.016(-5)? (STDERR)            ^^^
W20171020-14:19:36.018(-5)? (STDERR)
W20171020-14:19:36.019(-5)? (STDERR) SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode
W20171020-14:19:36.021(-5)? (STDERR)     at Object.exports.runInThisContext (vm.js:53:16)
W20171020-14:19:36.022(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:332:30
W20171020-14:19:36.023(-5)? (STDERR)     at Array.forEach (native)
W20171020-14:19:36.025(-5)? (STDERR)     at Function._.each._.forEach (C:\dev\programs\.meteor\packages\meteor-tool\1.5.2_2\mt-os.windows.x86_32\dev_b
undle\server-lib\node_modules\underscore\underscore.js:79:11)
W20171020-14:19:36.026(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:158:5
W20171020-14:19:36.028(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:388:5
W20171020-14:19:36.029(-5)? (STDERR)     at Function.run (C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\profile.js:510:12)
W20171020-14:19:36.031(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:387:11
=> Exited with code: 1
W20171020-14:19:40.739(-5)? (STDERR) C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\packages\ejson.js:749
W20171020-14:19:40.741(-5)? (STDERR)       for (let i = 0; i < length; i += 1) {
W20171020-14:19:40.745(-5)? (STDERR)            ^^^
W20171020-14:19:40.752(-5)? (STDERR)
W20171020-14:19:40.754(-5)? (STDERR) SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode
W20171020-14:19:40.756(-5)? (STDERR)     at Object.exports.runInThisContext (vm.js:53:16)
W20171020-14:19:40.757(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:332:30
W20171020-14:19:40.759(-5)? (STDERR)     at Array.forEach (native)
W20171020-14:19:40.762(-5)? (STDERR)     at Function._.each._.forEach (C:\dev\programs\.meteor\packages\meteor-tool\1.5.2_2\mt-os.windows.x86_32\dev_b
undle\server-lib\node_modules\underscore\underscore.js:79:11)
W20171020-14:19:40.765(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:158:5
W20171020-14:19:40.767(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:388:5
W20171020-14:19:40.769(-5)? (STDERR)     at Function.run (C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\profile.js:510:12)
W20171020-14:19:40.771(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:387:11
=> Exited with code: 1
W20171020-14:19:45.026(-5)? (STDERR) C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\packages\ejson.js:749
W20171020-14:19:45.028(-5)? (STDERR)       for (let i = 0; i < length; i += 1) {
W20171020-14:19:45.030(-5)? (STDERR)            ^^^
W20171020-14:19:45.031(-5)? (STDERR)
W20171020-14:19:45.033(-5)? (STDERR) SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode
W20171020-14:19:45.034(-5)? (STDERR)     at Object.exports.runInThisContext (vm.js:53:16)
W20171020-14:19:45.036(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:332:30
W20171020-14:19:45.037(-5)? (STDERR)     at Array.forEach (native)
W20171020-14:19:45.039(-5)? (STDERR)     at Function._.each._.forEach (C:\dev\programs\.meteor\packages\meteor-tool\1.5.2_2\mt-os.windows.x86_32\dev_b
undle\server-lib\node_modules\underscore\underscore.js:79:11)
W20171020-14:19:45.042(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:158:5
W20171020-14:19:45.043(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:388:5
W20171020-14:19:45.045(-5)? (STDERR)     at Function.run (C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\profile.js:510:12)
W20171020-14:19:45.047(-5)? (STDERR)     at C:\dev\R&D\meteor\meteor-test\.meteor\local\build\programs\server\boot.js:387:11
=> Exited with code: 1
=> Your application is crashing. Waiting for file change.

Answer 1

在Meteor中编写代码时，您必须注意语法。虽然流星运行在Node.JS之上，但它运行在比大多数NodeJs项目( NodeJS 6.x被认为是LTS)更老的版本上(例如，流星1.5与NodeJS v4.8.x捆绑在一起)。

在您的例子中，看起来像是在for循环中使用let。在NodeJS 7.x (source)之前，似乎不支持此语法。相反，请使用var (这是较旧的Javascript标准)。

在使用流星时，我强烈建议使用预编译语言(如Typescript)，因为它使您能够使用现代语法，这些语法将与流星的后续版本兼容(Node 8.x将成为流星1.6的一部分)。