The 'test_cmp_rev' helper is merely a wrapper around 'test_cmp' checking the output of two 'git rev-parse' commands, which means that its output on failure is not particularly informative, as it's basically two OIDs with a bit of extra clutter of the diff header, but without any indication of which two revisions have caused the failure: --- expect.rev 2018-11-17 14:02:11.569747033 +0000 +++ actual.rev 2018-11-17 14:02:11.569747033 +0000 @@ -1 +1 @@ -d79ce1670bdcb76e6d1da2ae095e890ccb326ae9 +139b20d8e6c5b496de61f033f642d0e3dbff528d It also pollutes the test repo with these two intermediate files, though that doesn't seem to cause any complications in our current tests (meaning that I couldn't find any tests that have to work around the presence of these files by explicitly removing or ignoring them). Enhance 'test_cmp_rev' to provide a more useful output on failure with less clutter: error: two revisions point to different objects: 'HEAD^': d79ce1670bdcb76e6d1da2ae095e890ccb326ae9 'extra': 139b20d8e6c5b496de61f033f642d0e3dbff528d Doing so is more convenient when storing the OIDs outputted by 'git rev-parse' in a local variable each, which, as a bonus, won't pollute the repository with intermediate files. While at it, also ensure that 'test_cmp_rev' is invoked with the right number of parameters, namely two. Signed-off-by: SZEDER Gábor <szeder.dev@xxxxxxxxx> --- t/test-lib-functions.sh | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh index d158c8d0bf..fc84db67a1 100644 --- a/t/test-lib-functions.sh +++ b/t/test-lib-functions.sh @@ -854,9 +854,23 @@ test_must_be_empty () { # Tests that its two parameters refer to the same revision test_cmp_rev () { - git rev-parse --verify "$1" >expect.rev && - git rev-parse --verify "$2" >actual.rev && - test_cmp expect.rev actual.rev + if test $# != 2 + then + error "bug in the test script: test_cmp_rev requires two revisions, but got $#" + else + local r1 r2 + r1=$(git rev-parse --verify "$1") && + r2=$(git rev-parse --verify "$2") && + if test "$r1" != "$r2" + then + cat >&4 <<-EOF + error: two revisions point to different objects: + '$1': $r1 + '$2': $r2 + EOF + return 1 + fi + fi } # Print a sequence of integers in increasing order, either with -- 2.20.0.rc0.134.gf0022f8e60