1437377 - Use dedicated error message when using "in" operator on non-string/non-object

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement, P3)

Description

[Tooru Fujisawa [:arai]]

The error message for `string in string` case is improved in bug 1352429,
but now it's a bit mis-leading for `string in undefined` or `string in null` case,
that should happen more in practice.

we should use more descriptive message for those cases.

Comment 1

[Tooru Fujisawa [:arai]]

Attachment: Use dedicated error message when using "in" operator on non-string/non-object.

non-string/non-object cases:

  js> "foo" in undefined
  typein:1:1 TypeError: right-hand side of 'in' should be an object, got undefined
  js> "foo" in null
  typein:2:1 TypeError: right-hand side of 'in' should be an object, got null
  js> "foo" in 10
  typein:3:1 TypeError: right-hand side of 'in' should be an object, got number
  js> "foo" in true
  typein:4:1 TypeError: right-hand side of 'in' should be an object, got boolean
  js> "foo" in Symbol.iterator
  typein:5:1 TypeError: right-hand side of 'in' should be an object, got symbol

string case:

  js> "foo" in "bar"
  typein:6:1 TypeError: cannot use 'in' operator to search for 'foo' in 'bar'

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/ca314f76eb1c
Use dedicated error message when using "in" operator on non-string/non-object. r=jwalden

Comment 3

[Tooru Fujisawa [:arai]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/ca314f76eb1cea65c3999a42960d57ef0eb3e78f
Bug 1437377 - Use dedicated error message when using "in" operator on non-string/non-object. r=jwalden

Comment 4

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/ca314f76eb1c

Comment 5

[Florian Scholz (Open Web Docs)]

Updated https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/in_operator_no_object to talk about the new messages.