Inaccurate test coverage might be caused by emojis

[eibens]

Hi, I am having an issue where the output of deno coverage appears inaccurate. I was able to narrow it down to a minimal example; instructions below. I hope it is reproducible. The problem goes away if the emojis or the unused function h are removed. Removing a single emoji removes line 2 from the coverage report, but still inaccurately keeps line 3. I have not tested it with other emojis ☺️

This is the mod.ts file:

export default function () {
  return "📣❓";
}

function h() {}

This is the mod_test.ts file:

import f from "./mod.ts";

Deno.test("test", () => {
  f()
});

These are the shell commands:

deno test --coverage=.cov
deno coverage .cov
rm -rf .cov

This is the output of deno coverage. As far as I understand it, line 2 and 3 should be covered:

 cover file:///home/mod.ts ... 25.000% (1/4)
   2 |   return "📣❓";
   3 | }
-----|-----
   5 | function h() {}

This is the output of deno --version:

deno 1.11.0 (release, x86_64-unknown-linux-gnu)
v8 9.1.269.35
typescript 4.3.2

[cdaringe]

I get a rust panic.

thread 'main' panicked at 'byte index 1090 is not a char boundary; it is inside '💣' (bytes 1088..1092) of `export class RadError extends Error {
    static message;
    static code;
    static emoji;
    reason;
}
RadError.code = "ERADERROR";
RadError.emoji = "🚨";
export class RadMissingRadFile extends RadError {
}
RadMissingRadFile.message = "unable to find`[...]', cli/tools/coverage.rs:230:25
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Seems pretty clear that the coverage checker is doing char mapping expecting byte chars, vs graphemes

[bartlomieju]

I got a panic as well:

============================================================
Deno has panicked. This is a bug in Deno. Please report this
at https://github.com/denoland/deno/issues/new.
If you can reliably reproduce this panic, include the
reproduction steps and re-run with the RUST_BACKTRACE=1 env
var set and include the backtrace in your report.

Platform: macos x86_64
Version: 1.17.2+1fb5858
Args: ["deno", "coverage", "./cov/", "--lcov", "--exclude=test\\.(ts|js)|wasm\\.js|testdata|node/_tools|node/_module/cjs|node_modules"]

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: BadJson(Error("invalid unicode code point", line: 1, column: 39318))', cli/tools/coverage.rs:202:57
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: Process completed with exit code 1.

[bartlomieju]

Reported an upstream issue, waiting for response.

[bartlomieju]

This should be soon fixed by denoland/deno_ast#88