TypeScript Bot (@typescript-bot) run dt.
TypeScript Bot (@typescript-bot) pack this.

The TypeScript team has xxyy

Heya Wenlu Wang (@Kingwl), I've started to run the tarball bundle task on this PR at 37ada55. You can monitor the build here.

Heya Wenlu Wang (@Kingwl), I've started to run the parallelized Definitely Typed test suite on this PR at 37ada55. You can monitor the build here.

Hey Wenlu Wang (@Kingwl), I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/80234/artifacts?artifactName=tgz&fileId=24EB196251C0700ECE50C8E4EF36FFE41ECC147DC5822099E673D2E05A67AFE302&fileName=/typescript-4.0.0-insiders.20200720.tgz"
    }
}

and then running npm install.

There is also a playground for this build.

Emmmm.... Need review and feedback

TypeScript Bot (@typescript-bot) pack this.

Heya Wenlu Wang (@Kingwl), I've started to run the tarball bundle task on this PR at 2fd560a. You can monitor the build here.

Hey Wenlu Wang (@Kingwl), I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/82712/artifacts?artifactName=tgz&fileId=F20A5C267D30CCAF558DD8B90945444BF1ECAF2C9D1D3EF7D1AECB09BA31230402&fileName=/typescript-4.1.0-insiders.20200819.tgz"
    }
}

and then running npm install.

There is also a playground for this build.

TypeScript Bot (@typescript-bot) pack this.

Yeah, I doubt we'll see anything significant, and I will likely merge if it's not too crazy seeing as we can optimize later.

Daniel Rosenwasser (@DanielRosenwasser)
The results of the perf run you requested are in!

Comparison Report - master..39669

Download Benchmark

The benchmark looks good, at least with the option off.

Daniel Rosenwasser (@DanielRosenwasser)
The results of the perf run you requested are in!

Comparison Report - master..39669

Download Benchmark

https://www.typescriptlang.org/play?ts=4.3.0-dev.20210406#code/MYGwhgzhAECK0G8CwAoa7oE8AUBKRAvqkSqJDACrQCmAHgC7UB2AJjPMmhgPYBu1AJwEBLFtSx5CxVEA

Is this expected? For code

class Q {
    y() {}
}
class T extends Q {
    override y() {}
}

The nightly playground emits the following JS code

"use strict";
class Q {
    y() { }
}
class T extends Q {
    override y() { }
}

which IMO is invalid. Is override y() {} a valid JS class member?

Jack Works (@Jack-Works) Nope. Fixed in #43536.

The compiler is complaining about the missing override keyword for constructor declared properties but it doesn't allow using the modifier on the constructor too.

Daniel Ferreira Monteiro Alves (@danfma) can you give an example?

Yes.

On the left side, it's the original code. So, I tried to put the override in the constructor like protected override readonly context... the compiler will complain.

We had to use like in the right side to force the compiler to accept the code.

Would we consider to add quickfix for parameter property or allow override in parameter property as Daniel Ferreira Monteiro Alves (@danfma) said.😂

By the way, this language feature fits me very well because I'm using an AST transformer to apply some Mobx decorators, and one of these modifiers is the “override” decorator! So, I can read the modifier and translate the code to what Mobx needs!

Thus, thank you! 😬

Wenlu Wang (@Kingwl) I think we’re going to allow override in the parameter property, but I’m going to run it by the design meeting on Wednesday.

Okay. Looking forward for the good news :XP

I've problems with static fields and override: #43916

What about methods that implement interface (as opposed to base class) members?

What about methods that implement interface (as opposed to base class) members?

No plan yet.

Is there a way to apply this to my entire project except to classes that inherit from a particular class (like React.Component, for example)?

Same question/need as Guilherme Simoes (@guilhermesimoes) - getting errors on state and render inside a React.Component is not helpful, but this flag would be very helpful outside of React (class) components.

without a way to exclude these (either by name, e.g. state, render, componentDidMount, etc.), or specifically for known React class properties (exceptReact or something), or even maybe include/exclude by directory or file extension (e.g. *.ts but not *.tsx), i can't use --noImplicitOverride in my project, but I have lots of non-React classes I'd love to have this protection apply to.

I realize that the TS team is not likely to want to have React-specific things in its codebase, but I just wanted to bring more attention to a common pain point with this feature for a subset of your users :)

Example errors for reference:

ERROR in src/SomeComponent/index.tsx:22:3
TS4114: This member must have an 'override' modifier because it overrides a member in the base class 'Component<IProps, IState, any>'.
    20 |   IState
    21 | > {
  > 22 |   state: IState = {}
       |   ^^^^^
    23 |
    24 |   render() {

ERROR in src/SomeComponent/index.tsx:24:3
TS4114: This member must have an 'override' modifier because it overrides a member in the base class 'Component<IProps, IState, any>'.
    22 |   state: IState = {}
    23 |
  > 24 |   render() {
       |   ^^^^^^
    25 |     return (