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lix/tests/test-infra.sh
John Ericson c11836126b Harden tests' bash
Use `set -u` and `set -o pipefail` to catch accidental mistakes and
failures more strongly.

 - `set -u` catches the use of undefined variables
 - `set -o pipefail` catches failures (like `set -e`) earlier in the
   pipeline.

This makes the tests a bit more robust. It is nice to read code not
worrying about these spurious success paths (via uncaught) errors
undermining the tests. Indeed, I caught some bugs doing this.

There are a few tests where we run a command that should fail, and then
search its output to make sure the failure message is one that we
expect. Before, since the `grep` was the last command in the pipeline
the exit code of those failing programs was silently ignored. Now with
`set -o pipefail` it won't be, and we have to do something so the
expected failure doesn't accidentally fail the test.

To do that we use `expect` and a new `expectStderr` to check for the
exact failing exit code. See the comments on each for why.

`grep -q` is replaced with `grepQuiet`, see the comments on that
function for why.

`grep -v` when we just want the exit code is replaced with `grepInverse,
see the comments on that function for why.

`grep -q -v` together is, surprise surprise, replaced with
`grepQuietInverse`, which is both combined.

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-03-08 10:26:30 -05:00

86 lines
1.9 KiB
Bash

# Test the functions for testing themselves!
# Also test some assumptions on how bash works that they rely on.
source common.sh
# `true` should exit with 0
expect 0 true
# `false` should exit with 1
expect 1 false
# `expect` will fail when we get it wrong
expect 1 expect 0 false
noisyTrue () {
echo YAY! >&2
true
}
noisyFalse () {
echo NAY! >&2
false
}
# These should redirect standard error to standard output
expectStderr 0 noisyTrue | grepQuiet YAY
expectStderr 1 noisyFalse | grepQuiet NAY
# `set -o pipefile` is enabled
pipefailure () {
# shellcheck disable=SC2216
true | false | true
}
expect 1 pipefailure
unset pipefailure
pipefailure () {
# shellcheck disable=SC2216
false | true | true
}
expect 1 pipefailure
unset pipefailure
commandSubstitutionPipeFailure () {
# shellcheck disable=SC2216
res=$(set -eu -o pipefail; false | true | echo 0)
}
expect 1 commandSubstitutionPipeFailure
# `set -u` is enabled
# note (...), making function use subshell, as unbound variable errors
# in the outer shell are *rightly* not recoverable.
useUnbound () (
set -eu
# shellcheck disable=SC2154
echo "$thisVariableIsNotBound"
)
expect 1 useUnbound
# ! alone unfortunately negates `set -e`, but it works in functions:
# shellcheck disable=SC2251
! true
funBang () {
! true
}
expect 1 funBang
unset funBang
# `grep -v -q` is not what we want for exit codes, but `grepInverse` is
# Avoid `grep -v -q`. The following line proves the point, and if it fails,
# we'll know that `grep` had a breaking change or `-v -q` may not be portable.
{ echo foo; echo bar; } | grep -v -q foo
{ echo foo; echo bar; } | expect 1 grepInverse foo
# `grepQuiet` is quiet
res=$(set -eu -o pipefail; echo foo | grepQuiet foo | wc -c)
(( res == 0 ))
unset res
# `greqQietInverse` is both
{ echo foo; echo bar; } | expect 1 grepQuietInverse foo
res=$(set -eu -o pipefail; echo foo | expect 1 grepQuietInverse foo | wc -c)
(( res == 0 ))
unset res