z4h's implementation of the direnv hook causes direnv's watch_file to not work

[hab25]

I.e. in .zshrc, using

zstyle ':z4h:direnv'         enable 'yes'
# Show "loading" and "unloading" notifications from direnv.
zstyle ':z4h:direnv:success' notify 'yes'

instead of

eval "$(direnv hook zsh)"

will cause direnv to not reload when a file watched by watch_file changes. Example:

---

.envrc contents:

#!/bin/bash
direnv_version 2.29.0
watch_file foo.txt

changing the contents of foo.txt does not cause direnv to reload the environment.

---

The reload does occur if using eval "$(direnv hook zsh)" instead, in .zshrc.
This is happening on Pop!_OS 21.10 .

[romkatv]

Thanks for the bug report. I'll take a look when I get a chunk of free time.

In the interim you can disable the built-in direnv integration in zsh4humans and enable direnv via the usual means.

[mawwwrk]

Hi,

first, thank you for sharing your creations, i've been using p10k from for a long time, and z4h since i discovered it. i've also learned a lot from reading your explanations on why some things are done the way they are.

i did some digging in the z4h/fn folder, to see if i could do something about this issue, and it looks like the problem was already identified, because the code for getting and decoding $DIRENV_WATCHES is already there, just commented out.

zsh4humans/fn/-z4h-direnv-hook

Line 17 in 6905da0

# { print -n '\x1f\x8b\x08\x00\x00\x00\x00\x00'; base64 -d <<<${${DIRENV_WATCHES//-/+}//_//} } | zcat 2>/dev/null

the code for getting the timestamp is also already in the code:

zsh4humans/fn/-z4h-direnv-hook

Line 34 in 6905da0

if zstat -A stat +mtime -- $envrc $files 2>/dev/null; then

i'm attempting to expand on this - i'm using tr and cut to extract lines from json, then i was thinking of using awk to run through each line and check for changes, but before i proceed i thought i'd ask: it looks to me like this is something someone with more experience would be able to easily solve, and it looks like a solution was partially done already, so is there some gotcha i'm not seeing?

also, if i'm on the right track, are there any zsh functions (builtins? i'm not sure of the terminology) i can look at to make script better?

some_seq='\x1f\x8b\x08\x00\x00\x00\x00\x00'

json_string=$({
    print -n "${some_seq}" ;
    base64 -d <<<${${DIRENV_WATCHES//-/+}//_//}
} | zcat 2>/dev/null )

# returns the original json string as comma-delimited lines
tr_cut(){
    local lines
    lines=$(echo "${json_string}" | tr '}' '\n' | cut -c 3- )

    local values
    values=$(echo "${lines}" | tr -d '"' | tr ':' ',' | cut -d ',' -f 2,4,6 )

    echo "${values}"
}

[romkatv]

The comments you've found is my unfinished solution. In order to finish it, three things are necessary:

1. Implement base64 decoding in pure zsh. This is necessary because base64 utility is not part of POSIX and currently z4h doesn't depend on it.
2. Replace zcat with a function that checks which commands are available and uses those. All commands that do the trick are here:

   zsh4humans/fn/-z4h-direnv-hook

   Lines 19 to 23 in 6905da0

   	# zcat
   	# gzcat
   	# uncompress -c
   	# gunzip -c
   	# gzip -cd

3. Implement a json parser in pure zsh. I already have one in powerlevel10k, so it's a matter of copying and adapting that code.

All of these are doable and aren't particularly difficult. I didn't do it because lazy.

[mawwwrk]

had a go at this. working as expected, so far.

Implement base64 decoding in pure zsh.

https://github.com/mawwwrk/zsh4humans/blob/05cc36cf1c22b68fc8b83acfad0fad6754d7dc72/fn/-z4h-direnv-hook#L32-L47

i think this is pure zsh. slightly concerned that it builds the hex->binary lookup array every time.

Replace zcat with a function that checks which commands are available and uses those.

https://github.com/mawwwrk/zsh4humans/blob/05cc36cf1c22b68fc8b83acfad0fad6754d7dc72/fn/-z4h-direnv-hook#L49-L55

returns the first value from the first available command that resembles a json array. it seems to work for all the apps except uncompress -c

Implement a json parser in pure zsh.

https://github.com/mawwwrk/zsh4humans/blob/05cc36cf1c22b68fc8b83acfad0fad6754d7dc72/fn/-z4h-direnv-hook#L57-L101

i grabbed your p10k json parser and mangled it a little, as it seems i really only need the file paths - then throw that back into the existing test for sig here:

https://github.com/mawwwrk/zsh4humans/blob/05cc36cf1c22b68fc8b83acfad0fad6754d7dc72/fn/-z4h-direnv-hook#L105-L106

thoughts?

also, a couple of questions:

https://github.com/romkatv/powerlevel10k/blob/406e6aa9e46429872c211d0c37517238ce9da3db/internal/p10k.zsh#L2249
field=${s:-x}
is this x here just an integer? i thought it might be a flag but upon closer inspection, there is a local -i x way up in the file.

zsh4humans/fn/-z4h-direnv-hook

Line 32 in fd101ce

local files=($^deps(N))

local files=($^deps(N))
i can't find this syntax $^ in the zsh guide. i assume its negation ^ and setting null_glob (N) ? how does it remove empty files/dirs?

[romkatv]

Wow, this looks great! I should have time to take a look at this in the next few days and merge it in.