| Message ID | 20180912183534.7486-1-wchargin@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v4] test_dir_is_empty: fix edge cases with newlines and hyphens | expand |
William Chargin <wchargin@gmail.com> writes: > While the `test_dir_is_empty` function appears correct in most normal > use cases, it can improperly pass if a directory contains a filename > with a newline, and can improperly fail if an empty directory looks like > an argument to `ls`. This patch changes the implementation to check that > the output of `ls -a` has at most two lines (for `.` and `..`), which > should be better behaved, and adds the `--` delimiter before the > directory name when invoking `ls`. AFIAK dot and dot-dot are allowed not to exist; "at most two" is not a good test. Quite honestly, our tests are still run inside a sort-of controlled environment, so if it _requires_ use of things we have avoided depending on, like "ls -A" and "xargs -0", or the fact that most filesystems always have "." and ".." even in an empty directory, in order to be resistant to funnily-named files like dot-LF-dot, I would say it is not worth worrying about these funny names--instead we can simply refrain from using such a pathological name, can't we? In other words, is there a real-world need in the context of our test suite for this change? Also, I find that its support for directories whose names begin with a dash red-herring. All the test scripts in our test suite knows that they can prefix "./" to avoid problems, i.e. test_dir_is_empty ./--wat So it appears that the only problematic case is when we create a directory, create a file or a directory whose name is dot-LF-dot and nothing else, and then do something that ought to cause that file to disappear, and make sure that the directory is empty, e.g. mkdir empty && echo foo >"empty/$dotLFdot" && git add "empty/$dotLFdot" && git reset --hard && test_dir_is_empty empty We do want to make sure funny names can be added with "git add" and "git reset --hard" to HEAD that lacked those paths with funny names to remove them correctly. But the funny names used in such a test do not have to be $dotLFdot; you can use "${dotLFdot}X" instead in the above and can ensure whatever the original test wanted to ensure. So...
diff --git a/t/t0000-basic.sh b/t/t0000-basic.sh index 850f651e4e..a5c57c6aa5 100755 --- a/t/t0000-basic.sh +++ b/t/t0000-basic.sh @@ -821,6 +821,49 @@ test_expect_success 'tests clean up even on failures' " EOF " +test_expect_success FUNNYNAMES \ + 'test_dir_is_empty behaves even in pathological cases' " + run_sub_test_lib_test \ + dir-empty 'behavior of test_dir_is_empty' <<-\\EOF && + test_expect_success 'should pass with actually empty directory' ' + mkdir empty_dir && + test_dir_is_empty empty_dir + ' + test_expect_success 'should fail with a normal filename' ' + mkdir nonempty_dir && + >nonempty_dir/some_file && + ! test_dir_is_empty nonempty_dir + ' + test_expect_success 'should fail with dot-newline-dot filename' ' + mkdir pathological_dir && + >\"pathological_dir/. + .\" && + ! test_dir_is_empty pathological_dir + ' + test_expect_success 'should pass with an empty directory \"-l\"' ' + mkdir -- -l && + test_dir_is_empty -l && + rmdir -- -l + ' + test_expect_success 'should pass with an empty directory \"--wat\"' ' + mkdir -- --wat && + test_dir_is_empty --wat && + rmdir -- --wat + ' + test_done + EOF + check_sub_test_lib_test dir-empty <<-\\EOF + > ok 1 - should pass with actually empty directory + > ok 2 - should fail with a normal filename + > ok 3 - should fail with dot-newline-dot filename + > ok 4 - should pass with an empty directory \"-l\" + > ok 5 - should pass with an empty directory \"--wat\" + > # passed all 5 test(s) + > 1..5 + EOF +" + + ################################################################ # Basics of the basics diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh index 4207af4077..3df6b8027f 100644 --- a/t/test-lib-functions.sh +++ b/t/test-lib-functions.sh @@ -576,7 +576,7 @@ test_path_exists () { # Check if the directory exists and is empty as expected, barf otherwise. test_dir_is_empty () { test_path_is_dir "$1" && - if test -n "$(ls -a1 "$1" | egrep -v '^\.\.?$')" + if test "$(ls -a1 -- "$1" | wc -l)" -gt 2 then echo "Directory '$1' is not empty, it contains:" ls -la "$1"
While the `test_dir_is_empty` function appears correct in most normal use cases, it can improperly pass if a directory contains a filename with a newline, and can improperly fail if an empty directory looks like an argument to `ls`. This patch changes the implementation to check that the output of `ls -a` has at most two lines (for `.` and `..`), which should be better behaved, and adds the `--` delimiter before the directory name when invoking `ls`. The newly added unit test fails before this change and passes after it. Signed-off-by: William Chargin <wchargin@gmail.com> --- This patch depends on "t: factor out FUNNYNAMES as shared lazy prereq" (2018-08-06), which is now in master. I originally wrote this patch for the standalone Sharness library, but that library advises that such patches be sent to the Git mailing list first. Tested on GNU/Linux (Mint 18.2) and macOS (10.13). t/t0000-basic.sh | 43 +++++++++++++++++++++++++++++++++++++++++ t/test-lib-functions.sh | 2 +- 2 files changed, 44 insertions(+), 1 deletion(-)