ctx.query is not a plain object while ctx.params and ctx.request.body is

[raphaelsoul]

As screenshot shows that ctx.query has no method hasOwnProperty from prototype

Which causes some package depends on ctx.query.hasOwnProperty calling an undefined method.

I am using koa@2.11.0

[cmidkiff87]

(Not a koajs dev, but had the same issue)

This is intended behavior as of node 6.
To get around it, you can use this instead

Object.hasOwnProperty.call(ctx.query, 'prop_name_here');

If you can't do that (such as using a library), you can shim it instead

app.use(async (ctx, next) => {

  ctx.query.hasOwnProperty = function(key) {
    // `this` === `ctx.query`
    return Object.hasOwnProperty.call(this, key);
  }
});

If that causes issues with object enumeration (let key of ctx.query erroring on 'hasOwnProperty'), you can make it unenumerable

app.use(async (ctx, next) => {

  function hasOwnPropertyShim(key) {
    // `this` === `ctx.query`
    return Object.hasOwnProperty.call(this, key);
  }

  Object.defineProperty(ctx.query, 'hasOwnProperty', {
    value: hasOwnPropertyShim,
    enumerable: false,
  });
});

[raphaelsoul]

(Not a koajs dev, but had the same issue)

This is intended behavior as of node 6.
To get around it, you can use this instead

Object.hasOwnProperty.call(ctx.query, 'prop_name_here');

If you can't do that (such as using a library), you can shim it instead

app.use(async (ctx, next) => {

  ctx.query.hasOwnProperty = function(key) {
    // `this` === `ctx.query`
    return Object.hasOwnProperty.call(this, key);
  }
});

If that causes issues with object enumeration (let key of ctx.query erroring on 'hasOwnProperty'), you can make it unenumerable

app.use(async (ctx, next) => {

  function hasOwnPropertyShim(key) {
    // `this` === `ctx.query`
    return Object.hasOwnProperty.call(this, key);
  }

  Object.defineProperty(ctx.query, 'hasOwnProperty', {
    value: hasOwnPropertyShim,
    enumerable: false,
  });
});

hmmm indeed. But I am running in node v10.20.1.
Currently i did like this validate({ ...ctx.query }) as a workaround

[cmidkiff87]

Node 10 has the same behavior.

Specifically

The object returned by the querystring.parse() method does not prototypically inherit from the JavaScript Object. This means that typical Object methods such as obj.toString(), obj.hasOwnProperty(), and others are not defined and will not work.

[dead-horse]

This behavior is by design to avoid some security problems.

https://stackoverflow.com/questions/52366192/why-does-node-js-querystring-parse-returns-an-object-that-does-not-inherit-fro

[dead-horse]

Close for now. If you have any other doubts you can continue the discussion. :)