Typescript error for builtins.ts

[willemneal]

I'm in the process of updating visitor-as to use the newest version of the compiler. For some reason I get the following error:

../assemblyscript/src/builtins.ts:1544:9 - error TS2367: This condition will always return 'true' since the types 'BinaryOp' and '-1' have no overlap.

1544     if (op != -1) {
             ~~~~~~~~

../assemblyscript/src/builtins.ts:1623:9 - error TS2367: This condition will always return 'true' since the types 'BinaryOp' and '-1' have no overlap.

1623     if (op != -1) {
             ~~~~~~~~


Found 2 errors.

This is strange because the IDE will report this error, but when compiling tsc -p src there were no errors. Clearly the fix is to add as i32 to make tsc not mad, but I'm wondering if I'm missing something.

The weirdest part is that I was able to get visitor-as working by doing the same compile strategy as this repo. That is placing the tsconfig.json into the src directory and then compiling with tsc -p src.

I can't figure out why typescript behaves differently, but regardless should we considering fixing this if there are future projects that have a different setup?