[PATCH 0/3] t7004: cleanup and modernize brittle tests

[PATCH 0/3] t7004: cleanup and modernize brittle tests

[Siddharth Shrimali]

This patch series addresses some brittle testing patterns in t7004-tag.sh

The first patch follows a suggestion by Junio to remove redundant tag
counting in the invalid name test. The second and third patches extend
this cleanup to hardcoded global state and modernizing subshell patterns
that could otherwise suppress git exit codes.

---
This series is a follow-up to my previous patch "t7004: replace wc -l 
with modern test helpers". Thanks to Junio for the feedback on the last
patch. I have applied those changes here and have gone through the rest
of the file and fixed similar issues.

Siddharth Shrimali (3):
  t7004: drop hardcoded tag count in invalid name test
  t7004: dynamically grab expected state in tests
  t7004: avoid subshells to capture git exit codes

 t/t7004-tag.sh | 43 +++++++++++++++++++++----------------------
 1 file changed, 21 insertions(+), 22 deletions(-)

-- 
2.51.2

[PATCH 1/3] t7004: drop hardcoded tag count in invalid name test

[Siddharth Shrimali]

The test 'trying to create a tag with a non-valid name should fail',
checked that exactly one tag existed in the repository before and after
attempting to create invalid tags.

As pointed out by Junio, this makes the test brittle by relying on a
specific global tag count. If future tests are added or removed before
this test, the expected state changes and this test would break for
completely unrelated reasons.

Since we already use 'test_must_fail' to guarantee that the invalid
tags are rejected by Git, counting the tags before and after is redundant.

Drop the 'test_line_count = 1' checks so the test doesn't rely on the
exact number of tags left behind by earlier tests.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
---
 t/t7004-tag.sh | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index faf7d97fc4..6ca5c75b57 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -191,15 +191,11 @@ test_expect_success 'trying to create a tag with the name of one existing should
 '
 
 test_expect_success 'trying to create a tag with a non-valid name should fail' '
-	git tag -l >actual &&
-	test_line_count = 1 actual &&
 	test_must_fail git tag "" &&
 	test_must_fail git tag .othertag &&
 	test_must_fail git tag "other tag" &&
 	test_must_fail git tag "othertag^" &&
-	test_must_fail git tag "other~tag" &&
-	git tag -l >actual &&
-	test_line_count = 1 actual
+	test_must_fail git tag "other~tag"
 '
 
 test_expect_success 'creating a tag using HEAD directly should succeed' '
-- 
2.51.2

[PATCH 2/3] t7004: dynamically grab expected state in tests

[Siddharth Shrimali]

The tests for 'Multiple -l or --list options' and 'trying to delete
tags without params', hardcodes that exactly one or two specific tags
('myhead', 'mytag') exist in the repository.

If other tests are added, modified, or removed earlier in the script,
this expected global state will change, resulting in these tests to fail
for completely unrelated reasons.

Instead of hardcoding the expected tags, dynamically grab the state
of the repository before running the commands under test ('git tag -l'
and 'git tag -d'), and verify that the output matches or remains
unchanged afterward. This keeps the tests independent from the script's
overall state.

Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
---
 t/t7004-tag.sh | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 6ca5c75b57..4fdd47cd21 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -145,9 +145,7 @@ test_expect_success 'listing all tags if one exists should succeed' '
 '
 
 test_expect_success 'Multiple -l or --list options are equivalent to one -l option' '
-	cat >expect <<-\EOF &&
-	mytag
-	EOF
+	git tag -l >expect &&
 	git tag -l -l >actual &&
 	test_cmp expect actual &&
 	git tag --list --list >actual &&
@@ -223,12 +221,7 @@ test_expect_success 'trying to delete an unknown tag should fail' '
 '
 
 test_expect_success 'trying to delete tags without params should succeed and do nothing' '
-	cat >expect <<-\EOF &&
-	myhead
-	mytag
-	EOF
-	git tag -l >actual &&
-	test_cmp expect actual &&
+	git tag -l >expect &&
 	git tag -d &&
 	git tag -l >actual &&
 	test_cmp expect actual
-- 
2.51.2

[PATCH 3/3] t7004: avoid subshells to capture git exit codes

[Siddharth Shrimali]

Several tests in t7004 use the 'test$(git ...) = ...' or the '! (git ...)'
subshell pattern. This swallows git's exit code. If git crashes
(e.g. segmentation fault) the crash would go undetected, and the test
would fail due to a mismatch or an inverted exit code.

Modernize these tests by directly writing output to files(actual) and
verifying them with 'test_cmp' or 'test_grep'. Replace subshell
negations with 'test_must_fail'. This way, if git crashes, the test
fails immediately and clearly instead of hiding the error behind a
string mismatch.

Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
---
 t/t7004-tag.sh | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 4fdd47cd21..e8c59c9105 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -155,8 +155,10 @@ test_expect_success 'Multiple -l or --list options are equivalent to one -l opti
 '
 
 test_expect_success 'listing all tags if one exists should output that tag' '
-	test $(git tag -l) = mytag &&
-	test $(git tag) = mytag
+	git tag -l >actual &&
+	test_grep "^mytag$" actual &&
+	git tag >actual &&
+	test_grep "^mytag$" actual
 '
 
 # pattern matching:
@@ -166,11 +168,15 @@ test_expect_success 'listing a tag using a matching pattern should succeed' '
 '
 
 test_expect_success 'listing a tag with --ignore-case' '
-	test $(git tag -l --ignore-case MYTAG) = mytag
+	echo mytag >expect &&
+	git tag -l --ignore-case MYTAG >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'listing a tag using a matching pattern should output that tag' '
-	test $(git tag -l mytag) = mytag
+	echo mytag >expect &&
+	git tag -l mytag >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'listing tags using a non-matching pattern should succeed' '
@@ -427,8 +433,12 @@ test_expect_success 'listing tags -n in column with column.ui ignored' '
 
 test_expect_success 'a non-annotated tag created without parameters should point to HEAD' '
 	git tag non-annotated-tag &&
-	test $(git cat-file -t non-annotated-tag) = commit &&
-	test $(git rev-parse non-annotated-tag) = $(git rev-parse HEAD)
+	echo commit >expect &&
+	git cat-file -t non-annotated-tag >actual &&
+	test_cmp expect actual &&
+	git rev-parse HEAD >expect &&
+	git rev-parse non-annotated-tag >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'trying to verify an unknown tag should fail' '
@@ -1517,11 +1527,11 @@ test_expect_success GPG 'verify signed tag fails when public key is not present'
 '
 
 test_expect_success 'git tag -a fails if tag annotation is empty' '
-	! (GIT_EDITOR=cat git tag -a initial-comment)
+	test_must_fail env GIT_EDITOR=cat git tag -a initial-comment
 '
 
 test_expect_success 'message in editor has initial comment' '
-	! (GIT_EDITOR=cat git tag -a initial-comment >actual)
+	test_must_fail env GIT_EDITOR=cat git tag -a initial-comment >actual
 '
 
 test_expect_success 'message in editor has initial comment: first line' '
-- 
2.51.2

Re: [PATCH 1/3] t7004: drop hardcoded tag count in invalid name test

[Junio C Hamano]

Siddharth Shrimali <r.siddharth.shrimali@gmail.com> writes:

> The test 'trying to create a tag with a non-valid name should fail',
> checked that exactly one tag existed in the repository before and after
> attempting to create invalid tags.
>
> As pointed out by Junio, this makes the test brittle by relying on a
> specific global tag count. If future tests are added or removed before
> this test, the expected state changes and this test would break for
> completely unrelated reasons.
>
> Since we already use 'test_must_fail' to guarantee that the invalid
> tags are rejected by Git, counting the tags before and after is redundant.
>
> Drop the 'test_line_count = 1' checks so the test doesn't rely on the
> exact number of tags left behind by earlier tests.

The only thing I suggested was that relying on exact state before
this test makes this test brittle.  I do not necessarily think
"redundant" is bad.  Having belt-and-suspenders sometimes help.

Alternatively, if we wanted to catch a bug where "git tag" exits
with a non-zero status, satisfying test_must_fail, but still creates
the requested tag, then we could do

	git tag -l >tags-before &&
	test_must_fail git tag "" &&
	... random attempts to create with invalid names ...
	test_must_fail git tag "other~tag" &&
	git tag -l >tags-after &&
	test_cmp tags-before tags-after

instead.   And that is a belt-and-suspenders approach.

Having said that, the patch is already an improvement, so let's take
it as is.  Unless there are other things we may want to improve in
this or other patches in the series, that is.

Thanks.

> Suggested-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
> ---
>  t/t7004-tag.sh | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
> index faf7d97fc4..6ca5c75b57 100755
> --- a/t/t7004-tag.sh
> +++ b/t/t7004-tag.sh
> @@ -191,15 +191,11 @@ test_expect_success 'trying to create a tag with the name of one existing should
>  '
>  
>  test_expect_success 'trying to create a tag with a non-valid name should fail' '
> -	git tag -l >actual &&
> -	test_line_count = 1 actual &&
>  	test_must_fail git tag "" &&
>  	test_must_fail git tag .othertag &&
>  	test_must_fail git tag "other tag" &&
>  	test_must_fail git tag "othertag^" &&
> -	test_must_fail git tag "other~tag" &&
> -	git tag -l >actual &&
> -	test_line_count = 1 actual
> +	test_must_fail git tag "other~tag"
>  '
>  
>  test_expect_success 'creating a tag using HEAD directly should succeed' '

Re: [PATCH 2/3] t7004: dynamically grab expected state in tests

[Junio C Hamano]

Siddharth Shrimali <r.siddharth.shrimali@gmail.com> writes:

> The tests for 'Multiple -l or --list options' and 'trying to delete
> tags without params', hardcodes that exactly one or two specific tags
> ('myhead', 'mytag') exist in the repository.
>
> If other tests are added, modified, or removed earlier in the script,
> this expected global state will change, resulting in these tests to fail
> for completely unrelated reasons.
>
> Instead of hardcoding the expected tags, dynamically grab the state
> of the repository before running the commands under test ('git tag -l'
> and 'git tag -d'), and verify that the output matches or remains
> unchanged afterward. This keeps the tests independent from the script's
> overall state.
>
> Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
> ---
>  t/t7004-tag.sh | 11 ++---------
>  1 file changed, 2 insertions(+), 9 deletions(-)

Excellent.  I agree with both reasoning above and execution below.

>
> diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
> index 6ca5c75b57..4fdd47cd21 100755
> --- a/t/t7004-tag.sh
> +++ b/t/t7004-tag.sh
> @@ -145,9 +145,7 @@ test_expect_success 'listing all tags if one exists should succeed' '
>  '
>  
>  test_expect_success 'Multiple -l or --list options are equivalent to one -l option' '
> -	cat >expect <<-\EOF &&
> -	mytag
> -	EOF
> +	git tag -l >expect &&
>  	git tag -l -l >actual &&
>  	test_cmp expect actual &&
>  	git tag --list --list >actual &&
> @@ -223,12 +221,7 @@ test_expect_success 'trying to delete an unknown tag should fail' '
>  '
>  
>  test_expect_success 'trying to delete tags without params should succeed and do nothing' '
> -	cat >expect <<-\EOF &&
> -	myhead
> -	mytag
> -	EOF
> -	git tag -l >actual &&
> -	test_cmp expect actual &&
> +	git tag -l >expect &&
>  	git tag -d &&
>  	git tag -l >actual &&
>  	test_cmp expect actual

Re: [PATCH 1/3] t7004: drop hardcoded tag count in invalid name test

[Patrick Steinhardt]

On Tue, Apr 14, 2026 at 09:54:23AM -0700, Junio C Hamano wrote:
> Siddharth Shrimali <r.siddharth.shrimali@gmail.com> writes:
> 
> > The test 'trying to create a tag with a non-valid name should fail',
> > checked that exactly one tag existed in the repository before and after
> > attempting to create invalid tags.
> >
> > As pointed out by Junio, this makes the test brittle by relying on a
> > specific global tag count. If future tests are added or removed before
> > this test, the expected state changes and this test would break for
> > completely unrelated reasons.
> >
> > Since we already use 'test_must_fail' to guarantee that the invalid
> > tags are rejected by Git, counting the tags before and after is redundant.
> >
> > Drop the 'test_line_count = 1' checks so the test doesn't rely on the
> > exact number of tags left behind by earlier tests.
> 
> The only thing I suggested was that relying on exact state before
> this test makes this test brittle.  I do not necessarily think
> "redundant" is bad.  Having belt-and-suspenders sometimes help.
> 
> Alternatively, if we wanted to catch a bug where "git tag" exits
> with a non-zero status, satisfying test_must_fail, but still creates
> the requested tag, then we could do
> 
> 	git tag -l >tags-before &&
> 	test_must_fail git tag "" &&
> 	... random attempts to create with invalid names ...
> 	test_must_fail git tag "other~tag" &&
> 	git tag -l >tags-after &&
> 	test_cmp tags-before tags-after
> 
> instead.   And that is a belt-and-suspenders approach.
> 
> Having said that, the patch is already an improvement, so let's take
> it as is.  Unless there are other things we may want to improve in
> this or other patches in the series, that is.

Hm. We now rely on exit code alone, without verifying that the exit code
actually results in the expected behaviour. I'm a bit torn myself
whether this is sensible and a step into the right direction, and I
would have preferred the `test_cmp` piece above that you propose.

Patrick

[PATCH v2 0/3] t7004: cleanup and modernize brittle tests

[Siddharth Shrimali]

This patch series addresses brittle testing patterns in t7004-tag.sh. 

In this second version, the first patch has been updated to follow 
Junio's "belt-and-suspenders" suggestion. Instead of simply removing
the tag count check, it now uses 'test_cmp' to verify that the repository
state remains unchanged after failed tag creation attempts. This
maintains verification while removing the reliance on a hardcoded
global tag count.

Subsequent patches continue to modernize the script by removing 
hardcoded global state and replacing subshell patterns that could 
otherwise suppress Git exit codes, ensuring that crashes (like 
segmentation faults) are properly detected.

Thanks to Patrick and Junio for the feedback on v1 regarding
state verification.

---
Changes since v1:
- Updated patch 1 to use 'test_cmp' for state verification 
  instead of just dropping the count check.

Siddharth Shrimali (3):
  t7004: drop hardcoded tag count for state verification
  t7004: dynamically grab expected state in tests
  t7004: avoid subshells to capture git exit codes

 t/t7004-tag.sh | 44 +++++++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

-- 
2.51.2

[PATCH v2 1/3] t7004: drop hardcoded tag count for state verification

[Siddharth Shrimali]

The test 'trying to create a tag with a non-valid name should fail',
checked that exactly one tag existed in the repository before and after
attempting to create invalid tags.

As pointed out by Junio, this makes the test brittle by relying on a
specific global tag count. If future tests are added or removed before
this test, the expected state changes and this test would break for
completely unrelated reasons.

Modernize the test by taking a snapshot of the existing tags before the
failure attempts and comparing it to a snapshot taken after.
This provides a "belt-and-suspenders" approach: we verify that
'git tag' both exits with the expected error code and leaves the
repository state untouched, without being brittle to the specific
number of tags present.

This replaces the hardcoded 'test_line_count = 1' checks with 'test_cmp'
to ensure the tag list remains identical.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
---
 t/t7004-tag.sh | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index faf7d97fc4..77a7a9777d 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -191,15 +191,14 @@ test_expect_success 'trying to create a tag with the name of one existing should
 '
 
 test_expect_success 'trying to create a tag with a non-valid name should fail' '
-	git tag -l >actual &&
-	test_line_count = 1 actual &&
+	git tag -l >tags-before &&
 	test_must_fail git tag "" &&
 	test_must_fail git tag .othertag &&
 	test_must_fail git tag "other tag" &&
 	test_must_fail git tag "othertag^" &&
 	test_must_fail git tag "other~tag" &&
-	git tag -l >actual &&
-	test_line_count = 1 actual
+	git tag -l >tags-after &&
+	test_cmp tags-before tags-after
 '
 
 test_expect_success 'creating a tag using HEAD directly should succeed' '
-- 
2.51.2

[PATCH v2 2/3] t7004: dynamically grab expected state in tests

[Siddharth Shrimali]

The tests for 'Multiple -l or --list options' and 'trying to delete
tags without params', hardcodes that exactly one or two specific tags
('myhead', 'mytag') exist in the repository.

If other tests are added, modified, or removed earlier in the script,
this expected global state will change, resulting in these tests to fail
for completely unrelated reasons.

Instead of hardcoding the expected tags, dynamically grab the state
of the repository before running the commands under test ('git tag -l'
and 'git tag -d'), and verify that the output matches or remains
unchanged afterward. This keeps the tests independent from the script's
overall state.

Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
---
 t/t7004-tag.sh | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index 77a7a9777d..bef7618da2 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -145,9 +145,7 @@ test_expect_success 'listing all tags if one exists should succeed' '
 '
 
 test_expect_success 'Multiple -l or --list options are equivalent to one -l option' '
-	cat >expect <<-\EOF &&
-	mytag
-	EOF
+	git tag -l >expect &&
 	git tag -l -l >actual &&
 	test_cmp expect actual &&
 	git tag --list --list >actual &&
@@ -226,12 +224,7 @@ test_expect_success 'trying to delete an unknown tag should fail' '
 '
 
 test_expect_success 'trying to delete tags without params should succeed and do nothing' '
-	cat >expect <<-\EOF &&
-	myhead
-	mytag
-	EOF
-	git tag -l >actual &&
-	test_cmp expect actual &&
+	git tag -l >expect &&
 	git tag -d &&
 	git tag -l >actual &&
 	test_cmp expect actual
-- 
2.51.2

[PATCH v2 3/3] t7004: avoid subshells to capture git exit codes

[Siddharth Shrimali]

Several tests in t7004 use the 'test$(git ...) = ...' or the '! (git ...)'
subshell pattern. This swallows git's exit code. If git crashes
(e.g. segmentation fault) the crash would go undetected, and the test
would fail due to a mismatch or an inverted exit code.

Modernize these tests by directly writing output to files(actual) and
verifying them with 'test_cmp' or 'test_grep'. Replace subshell
negations with 'test_must_fail'. This way, if git crashes, the test
fails immediately and clearly instead of hiding the error behind a
string mismatch.

Signed-off-by: Siddharth Shrimali <r.siddharth.shrimali@gmail.com>
---
 t/t7004-tag.sh | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh
index bef7618da2..d918005dd9 100755
--- a/t/t7004-tag.sh
+++ b/t/t7004-tag.sh
@@ -155,8 +155,10 @@ test_expect_success 'Multiple -l or --list options are equivalent to one -l opti
 '
 
 test_expect_success 'listing all tags if one exists should output that tag' '
-	test $(git tag -l) = mytag &&
-	test $(git tag) = mytag
+	git tag -l >actual &&
+	test_grep "^mytag$" actual &&
+	git tag >actual &&
+	test_grep "^mytag$" actual
 '
 
 # pattern matching:
@@ -166,11 +168,15 @@ test_expect_success 'listing a tag using a matching pattern should succeed' '
 '
 
 test_expect_success 'listing a tag with --ignore-case' '
-	test $(git tag -l --ignore-case MYTAG) = mytag
+	echo mytag >expect &&
+	git tag -l --ignore-case MYTAG >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'listing a tag using a matching pattern should output that tag' '
-	test $(git tag -l mytag) = mytag
+	echo mytag >expect &&
+	git tag -l mytag >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'listing tags using a non-matching pattern should succeed' '
@@ -430,8 +436,12 @@ test_expect_success 'listing tags -n in column with column.ui ignored' '
 
 test_expect_success 'a non-annotated tag created without parameters should point to HEAD' '
 	git tag non-annotated-tag &&
-	test $(git cat-file -t non-annotated-tag) = commit &&
-	test $(git rev-parse non-annotated-tag) = $(git rev-parse HEAD)
+	echo commit >expect &&
+	git cat-file -t non-annotated-tag >actual &&
+	test_cmp expect actual &&
+	git rev-parse HEAD >expect &&
+	git rev-parse non-annotated-tag >actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'trying to verify an unknown tag should fail' '
@@ -1520,11 +1530,11 @@ test_expect_success GPG 'verify signed tag fails when public key is not present'
 '
 
 test_expect_success 'git tag -a fails if tag annotation is empty' '
-	! (GIT_EDITOR=cat git tag -a initial-comment)
+	test_must_fail env GIT_EDITOR=cat git tag -a initial-comment
 '
 
 test_expect_success 'message in editor has initial comment' '
-	! (GIT_EDITOR=cat git tag -a initial-comment >actual)
+	test_must_fail env GIT_EDITOR=cat git tag -a initial-comment >actual
 '
 
 test_expect_success 'message in editor has initial comment: first line' '
-- 
2.51.2

Re: [PATCH v2 0/3] t7004: cleanup and modernize brittle tests

[Patrick Steinhardt]

On Tue, Apr 21, 2026 at 11:03:31AM +0530, Siddharth Shrimali wrote:
> This patch series addresses brittle testing patterns in t7004-tag.sh. 
> 
> In this second version, the first patch has been updated to follow 
> Junio's "belt-and-suspenders" suggestion. Instead of simply removing
> the tag count check, it now uses 'test_cmp' to verify that the repository
> state remains unchanged after failed tag creation attempts. This
> maintains verification while removing the reliance on a hardcoded
> global tag count.
> 
> Subsequent patches continue to modernize the script by removing 
> hardcoded global state and replacing subshell patterns that could 
> otherwise suppress Git exit codes, ensuring that crashes (like 
> segmentation faults) are properly detected.
> 
> Thanks to Patrick and Junio for the feedback on v1 regarding
> state verification.

Thanks, this version looks good to me!

Patrick