Static keyword on function being removed from JS in minification

[vera-fied]

Are you using the latest verion of NUglify, especially if used through BunderMinifier? Update before raising a bug as your issue is probably already fixed.
Using latest 1.21.17

Describe the bug
When uglifying javascript the static keyword on functions can be removed, causing code to not execute properly.

To Reproduce
The minimal repro I've created is to have this base TS code:
namespace Test { export class TestElement extends HTMLElement { public static readonly tagName = "test" as const; public static override [Symbol.hasInstance](instance: unknown) { return instance instanceof Element && instance.tagName.toLowerCase() === this.tagName.toLowerCase(); } } }

Compile it however you want, module/target version doesn't seem to change the end result of uglifying. But my repro is using tsconfig:
{ "compilerOptions": { "module": "ES2020", "target": "ES2019", } }

Then put that through Uglify.Js and receive the output with static keyword removed from the Symbol.hasInstance override. This dotnetfiddle has the example: https://dotnetfiddle.net/0ow2Qa

Minified output or stack trace
var Test;(function(n){class t extends HTMLElement{[Symbol.hasInstance](n){return n instanceof Element&&n.tagName.toLowerCase()===this.tagName.toLowerCase()}}t.tagName="test";n.TestElement=t})(Test||(Test={}))

Excepted output code
var Test;(function(n){class t extends HTMLElement{static [Symbol.hasInstance](n){return n instanceof Element&&n.tagName.toLowerCase()===this.tagName.toLowerCase()}}t.tagName="test";n.TestElement=t})(Test||(Test={}))

[trullock]

Can you please provide input JS, TS has nothing to do with this :)

[vera-fied]

Ah sorry, input js was in the dotnetfiddle. Input js is:

(function (Test) {
    class TestElement extends HTMLElement {
        static [Symbol.hasInstance](instance) {
            return instance instanceof Element && instance.tagName.toLowerCase() === this.tagName.toLowerCase();
        }
    }    TestElement.tagName = "test"; 
   Test.TestElement = TestElement;})(Test || (Test = {}));""");```
		

[trullock]

Can you simplify that down please, you almost certainly dont need most of that to repro the issue

[vera-fied]

Yeah, here's more simplified down input js:

class TestElement extends HTMLElement { static [Symbol.hasInstance](instance) { return true; } }

It returns class TestElement extends HTMLElement{[Symbol.hasInstance](){return!0}} which is missing the static

It seems to be related to the [Symbol.hasInstance] piece as it only seems to fail when that exists, maybe something related to the square bracket processing for this scenario?

[trullock]

Can you create a test for this, and use RunErrorTest and see what error its spitting out?

Or otherwise consult the minification output for errors

[vera-fied]

Yeah, looks like it's trying to read Symbol as a variable

Standard Output: 
INPUT FILE: C:\src\NUglify\src\NUglify.Tests\bin\Debug\TestData\JS\Input\FunctionCreation\StaticFunction.js
class TestElement extends HTMLElement { static [Symbol.hasInstance](instance) { return true; } }

---ERRORS---
UndeclaredVariable
ArgumentNotReferenced

    
    Error JS1135 at Line 1, Column 49: Variable has not been declared: Symbol
        Variable has not been declared: Symbol
        UNEXPECTED
    
    Error JS1270 at Line 1, Column 69: Argument defined but not referenced: instance
        Argument defined but not referenced: instance
        UNEXPECTED

UNEXPECTED ERROR RESULTS

odd "C:\src\NUglify\src\NUglify.Tests\bin\Debug\TestData\JS\Expected\FunctionCreation\StaticFunction.js" "C:\src\NUglify\src\NUglify.Tests\bin\Debug\TestData\JS\Output\FunctionCreation\StaticFunction.js"

---Expected Code---
C:\src\NUglify\src\NUglify.Tests\bin\Debug\TestData\JS\Expected\FunctionCreation\StaticFunction.js
class TestElement extends HTMLElement { static [Symbol.hasInstance]() { return !0 } }


---Resulting Code---
C:\src\NUglify\src\NUglify.Tests\bin\Debug\TestData\JS\Output\FunctionCreation\StaticFunction.js
class TestElement extends HTMLElement{[Symbol.hasInstance](){return!0}}

[trullock]

there was a PR for fixing another static bug recently, take a peek and see if you can mirror the fix for this case

[SquGus]

I believe the PR @trullock is referring to is #418 . Please confirm.