Property 'includes' does not exist on type 'string[]'.

[monad98]

• I'm submitting a ...
  [*] bug report
  [ ] feature request
  [ ] question about the decisions made in the repository
• Do you want to request a feature or report a bug?
  report a bug
• What is the current behavior?
  I got following error.
  Property 'includes' does not exist on type 'string[]'.
• If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem
  After this commit, when I use 'Array.prototype.includes()' I got above error.
• What is the expected behavior?
  No errors.
• Please tell us about your environment:
  Angular version: 2.0.0-rc5
  Node v6.2.2
  NPM v 3.9.5

[rvalimaki]

I can confirm this problem. Obviously this affects to all Arrays, eg. "Property 'includes' does not exist on type 'number[]'."

I tried to change the ES target to ES6 with no success.

[rvalimaki]

Okay, to overcome the issue, I needed to set tsconfig.json compilerOptions.lib from "es6" to "es7" as follows:

"lib": [
  "dom",
  "es7"
],

I'm not sure if this causes other problems, though. "includes" is implemented for 'string' (not Array) in ES6, and for arrays only in ES7.

[KhaledElAnsari]

any updates on this?

btw I did a different approach to do what includes() do

let targetClasses: Array<string> = ["open_time", "close_time"];
let isThere: boolean = targetClasses.some(cls => (<HTMLElement>event.target).classList.contains(cls));
...

[rvalimaki]

@KhaledElAnsari

I don't think any updates are needed for this, since if you want to use ES7 features on your code, you have to set the "lib" version in tsconfig.json (and tsconfig.webpack.json) to "es7".

So I can't see any issues on Angular2 webpack starter or Angular2 itself regarding this. Just set the library version you want, and you are good to go.

This issue should be closed, or maybe the default library setting should be changed to ES7.

[karkokat]

What worked for me was just declare array with also its datatype like as: let array = []; instead of just let array; where is its datatype undefined.

[leotm]

@rvalimaki 's suggestion worked for me, just had to remember to Reload Window for the changes to take effect.