Do not use mtime comparision to determine file task execution

[srackham]

Timestamp-only file task dependency checking is fraught with problems, see mtime comparison
considered harmful.

This is further complicated by the fact that Deno.utime and Deno.utimeSync APIs have been marked
"unstable" in Deno 1.0.0-rc1 and they have resolution limitations.

Drake's file task dependency check mechanism should not rely on target and prerequisite file
timestamp comparisions.

[srackham]

Resolved with the introduction of file history caching in Drake v1.0.0-rc2.

[duncanmak]

@srackham I'm using Drake 1.5.2 and I noticed that on Windows, the mtime check in isOutOfDate is returning true all the time.

isOutOfDate: build\index.html: true: build\index.html
from: {"size":532,"mtime":"2022-06-07T21:29:05.186Z"}
to:   {"size":532,"mtime":"2022-06-07T23:21:29.811Z"}

I was scanning the same article you referred to, mtime comparison considered harmful, and I wonder if a better check could be implemented instead of checking that the result of Date.toISOString is !==.

An interesting note, I only see this error when running in Windows - on Linux (in WSL, no less), isOutOfDate returns false as expected after running the same target a second time.

[srackham]

Thanks for this, very interesting. I'll look into it when I get some free time.

[srackham]

@duncanmak The only possibilities I can think of are that somehow the Drake cache file is not being updated after a sucessful task execution (if the task action is executed sucessfully then the Drake cache should be updated) or the information returned by the Deno.statSync API is stale.

Try cloning the Drake repo and running the Drake tests on WSL with deno run -A Drakefile.ts test command (I don't have WSL installed).