nix/tests/function-trace.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

68 lines
1.6 KiB
Bash
Executable File

source common.sh
set +x
expect_trace() {
expr="$1"
expect="$2"
actual=$(
nix-instantiate \
--trace-function-calls \
--expr "$expr" 2>&1 \
| grep "function-trace" \
| sed -e 's/ [0-9]*$//' \
|| true
)
echo -n "Tracing expression '$expr'"
msg=$(diff -swB \
<(echo "$expect") \
<(echo "$actual")
) && result=0 || result=$?
if [ $result -eq 0 ]; then
echo " ok."
else
echo " failed. difference:"
echo "$msg"
return $result
fi
}
# failure inside a tryEval
expect_trace 'builtins.tryEval (throw "example")' "
function-trace entered «string»:1:1 at
function-trace entered «string»:1:19 at
function-trace exited «string»:1:19 at
function-trace exited «string»:1:1 at
"
# Missing argument to a formal function
expect_trace '({ x }: x) { }' "
function-trace entered «string»:1:1 at
function-trace exited «string»:1:1 at
"
# Too many arguments to a formal function
expect_trace '({ x }: x) { x = "x"; y = "y"; }' "
function-trace entered «string»:1:1 at
function-trace exited «string»:1:1 at
"
# Not enough arguments to a lambda
expect_trace '(x: y: x + y) 1' "
function-trace entered «string»:1:1 at
function-trace exited «string»:1:1 at
"
# Too many arguments to a lambda
expect_trace '(x: x) 1 2' "
function-trace entered «string»:1:1 at
function-trace exited «string»:1:1 at
"
# Not a function
expect_trace '1 2' "
function-trace entered «string»:1:1 at
function-trace exited «string»:1:1 at
"