Discussion on: What's Wrong This Time? Part II: Electric Bugaloo

[peerreynders]

but comparison functions are just one of those things that I've always had to test every time

If you need to rely on memorization:

• compare(a,b) > 0 then b before a

knowing that

function comparison(t1: T, t2: T): number {
  return t1.charCodeAt(0) - t2.charCodeAt(0)
}

• t1 = "cherry", t2 = "apple"
• 'c' - 'a' > 0 i.e. "apple" before "cherry"
• ascending order

function comparison(t1: T, t2: T): number {
  return t2 - t1
}

• note the "reversed" order in the operation
• t1 = 42, t2 = 2112
• so t2 - t1 > 0 i.e. 2112 before 42
• descending order

Is this painful?

Sure, hence

function byFirstCuAscending(t1: T, t2: T): number {
  return t1.charCodeAt(0) - t2.charCodeAt(0)
}

newArray.sort(byFirstCuAscending)

function byNumberDescending(t1: T, t2: T): number {
  return t2 - t1
}

newArray.sort(byNumberDescending)

i.e. state the intent.
One reason to steer clear of inline anonymous functions.

So What Happened?

I'm not convinced this has anything to do with sorting.

I could be wrong but I think there's some ambiguity when it comes to Simple Git's API (TypeScript or not). It mostly defers to the git log documentation (and Pretty Formats).

So given the amended code:

    const postCommits: RichCommit[] = await env.git.log([ 'master', `blog/${slug}.md` ]).
      then(commits => commits.all.filter(commit => commit.message != "Merge branch 'development'"));

it seems to be more a misunderstanding of the data that is being returned by the API.

Also given the way Simple Git depends on the Git documentation the date property name is tricky.

Commit Formatting

When =<format> part is omitted, it defaults to medium.

If Simple Git follows the Git convention then date would be "Author date". The "commit date" is only available with the fuller format as CommitDate or committer date.
(edit: it is the author date; the "commit date" requires a custom format option with Simple Git).

Viewing the Commit History

You may be wondering what the difference is between author and committer. The author is the person who originally wrote the work, whereas the committer is the person who last applied the work

So date may actually be the "Author Date" which may be good enough for your purposes as it refers to the time of git commit. But the actual "commit date" can be altered by other operations.

So if you need sorting by "author date" then perhaps an explicit sort may be the "safer" route.

This seems to be more related to (mis)understanding the data being manipulated/relied on. If anything, it demonstrated again how "naming things is hard".

[Andrew (he/him)]

There are definitely some quirks here re: author vs. committer, and the potential for commits to change due to cherry-picking, etc. Hopefully I don't make that much of a mess of the repo, though, as it's just me committing to it. But if I do, you can bet there'll be another blog post about what I learned from fixing it!

[peerreynders]

My biggest concern would be having to put the date back into the frontmatter to implement drafts (with a future date) - i.e. the oldest "author date" would no longer imply "publish date".

[Andrew (he/him)]

The way I'm doing drafts right now is prepending wip- to the filename, and .gitignore-ing blog/wip-*. That means that drafts aren't under version control. This is fine for me (for now) because usually I have zero or one drafts at any given time.

Bringing drafts into version control is an interesting problem. As you say, it would require basically throwing out the idea that first commit == published date. Maybe a drafts directory is the easiest way to go? git log <filename> doesn't follow file renames by default (see --follow), so moving a file from drafts/ to blog/ could essentially be the "trigger" for publication.

Interesting stuff. Thanks for pointing this out!