小编Mar*_*arc的帖子

在 Haskell 中，我们可以声明允许我们隐藏对底层数据类型的访问的新类型。这允许我们通过不暴露底层数组之类的东西（使库的用户不可能越界）来在模块中创建更安全的 API。

打字稿中是否有类似于 newtypes 的东西？

我使用Firebase云功能为QR文件上传编写了以下代码

const functions = require('firebase-functions');
const qrcode = require('qrcode')
const admin = require('firebase-admin');
const spawn = require('child-process-promise').spawn;
const serviceAccount = require("./secret.json");
const gcs = require('@google-cloud/storage')();

admin.initializeApp(functions.config({
  credential: admin.credential.cert(serviceAccount),
  storageBucket: "https://SECRET.firebaseio.com"
}));


exports.qrcode = functions.https.onRequest((req, res) => {
  const storage = admin.storage().bucket();
  const dummyFile = storage.file('dummy.png')
  new Promise ((resolve, reject) => qrcode.toFileStream(
    dummyFile.createWriteStream()
      .on('finish', resolve)
      .on('error', reject),
    'DummyQR'))
    .then(console.log("success")) //Doing stuff here later
    .catch(console.log)
  res.send("<script>window.close();</script>")
});

根据文档，我应该能够通过简单地调用admin.storage().bucket();（https://firebase.google.com/docs/storage/admin/start）连接到存储桶，但是出现以下错误：

Error: Error occurred while parsing your function triggers.

Error: Bucket …

我正在尝试将精力放在基于属性的测试和国际象棋上。目前，我将我的国际象棋游戏表示为2D数组，而我实现的唯一部件是用来作怪的典当和骑士。

典当和骑士代表他们的动作allMoves(x,y) \ invalidMoves(board,x,y)。因此，我可以想到的一项性能就是对其进行测试allMoves(x,y) ? invalidMoves(board,x,y) === allMoves。但是除此之外，我不确定还需要测试什么。我假设我需要为国际象棋棋盘建立一个简化的Oracle模型，但是我不确定这样的模型是什么。

I want to check if a type is nullable or not, and if it has a conditional type on the value.

I tried implementing

type IsNullable<T> = T extends null ? true : false;

However, it does not seem to work

type test = IsNullable<number> // Returns false as it should
type test = IsNullable<number | null> // Returns false when it should be true

What's the proper way of checking if a type is nullable? I tried with T …

我正在尝试在 Terraform 中设置 S3 存储桶策略。我在模块中编写了以下代码core/main.tf：

resource "aws_s3_bucket_policy" "access_to_bucket" {\n\n  bucket = aws_s3_bucket.some_bucket.id\n\n  policy = jsonencode({\n    Version = "2012-10-17"\n    Statement = [\n      {\n        Action    = ["s3:GetObject", "s3:GetObjectAcl", "s3:ListBucket"]\n        Effect    = "Allow"\n        Principal = "${var.some_variable_name}"\n        Resource = [\n          "${aws_s3_bucket.some_bucket.arn}",\n          "${aws_s3_bucket.some_bucket.arn}/*"\n        ]\n      },\n    ]\n  })\n}\n\n

然后在本地模块中实例化，该模块使用 localstack 在本地运行。

这是生成的计划：

Terraform will perform the following actions:\n\n  # module.local.aws_s3_bucket_policy.access_to_bucket will be created\n  + resource "aws_s3_bucket_policy" "access_to_bucket" {\n      + bucket = "some_bucket"\n      + id     = (known after apply)\n      + policy …