Compiling TS-Files with Special-Character in filename prints escaped filename as sourceMappingURL

[viyaha]

TypeScript Version: 4.2.0-dev.20201201 and 4.1.2

Search Terms: source map, sourcemap, escaping

Code

console.log("just testing... doesn't matter what we use here");

Expected behavior: (works in 4.0.5)
Compile-Output:

• {index}.js
• {index}.js.map

Content of {index}.js:

console.log("just testing... doesn't matter what we use here");
//# sourceMappingURL={index}.js.map

Actual behavior:
Compile-Output:

• {index}.js
• {index}.js.map

Content of {index}.js:

console.log("just testing... doesn't matter what we use here");
//# sourceMappingURL=%7Bindex%7D.js.map

Playground Link: Couldn't find a possibility to active sourceMap-Generation in Playground

[a-tarasyuk]

I suppose this is expected behavior, isn't it? #40951, #41102

/cc @RyanCavanaugh

[RyanCavanaugh]

@a-tarasyuk yep, you're right. Good catch.