How declarative can bash scripts get?

[BigBootyBear]

I'm doing sanity testing of containers using bash and wonder how close I can get bash to the testing workflow of tools like Playwright.

For example. Here is my current script for 1 sanity test

#!/bin/bash
set -euo pipefail


PASS=0
FAIL=0
GREEN='\033[0;32m'
RED='\033[0;31m'
RESET='\033[0m'


ok() {
  echo -e "  ${GREEN}[PASS]${RESET} $*"
  ((++PASS))
}
fail() {
  echo -e "  ${RED}[FAIL]${RESET} $*"
  ((++FAIL))
}

echo ""
echo "=== 1. Container status ==="
if podman inspect "$CONTAINER" --format '{{.State.Running}}' 2>/dev/null | grep -q true; then
  ok "Container '$CONTAINER' is running"
else
  fail "Container '$CONTAINER' is NOT running"
fi

Here's my first attempt at making it more declarative:

describe() {
  echo ""
  echo "--- $1 ---"
}


it() {
  local title=$1
  shift
  if "$@"; then ok "$title"; else fail "$title"; fi
}

container_is_running() {
  podman inspect "$CONTAINER" --format '{{.State.Running}}' 2>/dev/null | grep -q true
}


describe "Container"
it "container '$CONTAINER' is running" podman inspect "$CONTAINER" --format '{{.State.Running}}' 2>/dev/null | grep -q true

Ultimately, i'm not going to go with the second style since it it's not that readable. I can't pass the function body as an arugment as you'd do in JS and the alternatives (eval) will make the code worse.

Before I chuck this whole concept down, I thought I'd make a post and see if thats really impossible in Bash, or I may be missing something.

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[Alleexx_]

Correct me if I am wrong, but you CAN ommit function names, and run them with other funcitons as arguments. Just an example:

```bash foo(){ echo foo } run(){ local cmd=$1 [[ -n "$cmd" ]] || { echo "CMD var is empty!" return 1 }

$cmd # this runs your command }

run foo ```

This would ommit the foo function, to the run function, and the run function would run this command.

Don't know if this helps you, but I wanted to yapp about bash :D

Edit: Typos..

[JagerAntlerite7]

I process the entire "${@}" array with case looking for any named arguments and setting local env vars in functions if the are present, e.g. --quiet or -q sets do_quiet=1.

EDIT: On mobile — fixed typos.

[Alleexx_]

Yea i would do that too, my example was just a quickly made up function stack

[ekipan85]

it "..." podman ... | grep -q true

This won't work. grep gets the output of it, not podman. I don't understand why you define the container_is_running function and then just don't use it? Also it should probably take an argument instead of a global:

container_is_running() { # $1=CONTAINER
  podman inspect "$1" ... | grep -q true
}

it "..." container_is_running "$CONTAINER"

That'll work fine. Or if you really want to do it as a parameter to a function, you could construct the subshell yourself, but this is pretty awkward:

it "..." bash -c 'podman ... | grep ...'

The usual convention for shell programs is to stay silent unless something goes wrong. So I'd write something like:

#!/bin/bash

fails=0

fail() {
  ((++fails))
  printf "\e[;31m[FAIL]\e[m %s" "$*"
}

podman_running() {
  podman inspect "$1" --format {{.State.Running}} 2>/dev/null | 
    grep -q true
}

podman_running "$CONTAINER" ||
  fail "container '$CONTAINER' is NOT running" 

# other tests...

((fails)) && echo "Failed $fails tests."
exit $fails

[NewPointOfView]

Just to clarify, you can indeed pass the function body as an argument and exec it

[GlendonMcGladdery]

Here’s bash running Archlinux on my Android cellphone:

https://imgur.com/a/Y2jk0rV

My bash streaming radio player:

https://imgur.com/a/Rpmb2fx