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>

1 files changed, 12 insertions, 12 deletions

diff --git a/tests/binary-cache.sh b/tests/binary-cache.sh
index b38db8a15..7c64a115c 100644
--- a/tests/binary-cache.sh
+++ b/tests/binary-cache.sh
@@ -15,11 +15,11 @@ outPath=$(nix-build dependencies.nix --no-out-link)
 nix copy --to file://$cacheDir $outPath
 
 # Test copying build logs to the binary cache.
-nix log --store file://$cacheDir $outPath 2>&1 | grep 'is not available'
+expect 1 nix log --store file://$cacheDir $outPath 2>&1 | grep 'is not available'
 nix store copy-log --to file://$cacheDir $outPath
 nix log --store file://$cacheDir $outPath | grep FOO
 rm -rf $TEST_ROOT/var/log/nix
-nix log $outPath 2>&1 | grep 'is not available'
+expect 1 nix log $outPath 2>&1 | grep 'is not available'
 nix log --substituters file://$cacheDir $outPath | grep FOO
 
 # Test copying build logs from the binary cache.
@@ -78,8 +78,8 @@ mv $nar $nar.good
 mkdir -p $TEST_ROOT/empty
 nix-store --dump $TEST_ROOT/empty | xz > $nar
 
-nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result 2>&1 | tee $TEST_ROOT/log
-grep -q "hash mismatch" $TEST_ROOT/log
+expect 1 nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result 2>&1 | tee $TEST_ROOT/log
+grepQuiet "hash mismatch" $TEST_ROOT/log
 
 mv $nar.good $nar
 
@@ -126,9 +126,9 @@ clearStore
 rm -v $(grep -l "StorePath:.*dependencies-input-2" $cacheDir/*.narinfo)
 
 nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result 2>&1 | tee $TEST_ROOT/log
-grep -q "copying path.*input-0" $TEST_ROOT/log
-grep -q "copying path.*input-2" $TEST_ROOT/log
-grep -q "copying path.*top" $TEST_ROOT/log
+grepQuiet "copying path.*input-0" $TEST_ROOT/log
+grepQuiet "copying path.*input-2" $TEST_ROOT/log
+grepQuiet "copying path.*top" $TEST_ROOT/log
 
 
 # Idem, but without cached .narinfo.
@@ -136,11 +136,11 @@ clearStore
 clearCacheCache
 
 nix-build --substituters "file://$cacheDir" --no-require-sigs dependencies.nix -o $TEST_ROOT/result 2>&1 | tee $TEST_ROOT/log
-grep -q "don't know how to build" $TEST_ROOT/log
-grep -q "building.*input-1" $TEST_ROOT/log
-grep -q "building.*input-2" $TEST_ROOT/log
-grep -q "copying path.*input-0" $TEST_ROOT/log
-grep -q "copying path.*top" $TEST_ROOT/log
+grepQuiet "don't know how to build" $TEST_ROOT/log
+grepQuiet "building.*input-1" $TEST_ROOT/log
+grepQuiet "building.*input-2" $TEST_ROOT/log
+grepQuiet "copying path.*input-0" $TEST_ROOT/log
+grepQuiet "copying path.*top" $TEST_ROOT/log
 
 
 # Create a signed binary cache.