nix/tests/pure-eval.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

35 lines
1.4 KiB
Bash

source common.sh
clearStore
nix eval --expr 'assert 1 + 2 == 3; true'
[[ $(nix eval --impure --expr 'builtins.readFile ./pure-eval.sh') =~ clearStore ]]
missingImpureErrorMsg=$(! nix eval --expr 'builtins.readFile ./pure-eval.sh' 2>&1)
echo "$missingImpureErrorMsg" | grepQuiet -- --impure || \
fail "The error message should mention the “--impure” flag to unblock users"
[[ $(nix eval --expr 'builtins.pathExists ./pure-eval.sh') == false ]] || \
fail "Calling 'pathExists' on a non-authorised path should return false"
(! nix eval --expr builtins.currentTime)
(! nix eval --expr builtins.currentSystem)
(! nix-instantiate --pure-eval ./simple.nix)
[[ $(nix eval --impure --expr "(import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; })).x") == 123 ]]
(! nix eval --expr "(import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; })).x")
nix eval --expr "(import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; sha256 = \"$(nix hash file pure-eval.nix --type sha256)\"; })).x"
rm -rf $TEST_ROOT/eval-out
nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ x = "foo" + "bar"; y = { z = "bla"; }; }'
[[ $(cat $TEST_ROOT/eval-out/x) = foobar ]]
[[ $(cat $TEST_ROOT/eval-out/y/z) = bla ]]
rm -rf $TEST_ROOT/eval-out
(! nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ "." = "bla"; }')
(! nix eval --expr '~/foo')