threads / patch / 46412

patcht8008: rely on rev-parse'd HEAD instead of sha1 value

Subject: [PATCH] t8008: rely on rev-parse'd HEAD instead of sha1 value

## tl;dr

6 messages between Jul 18, 2017 and Jul 26, 2017. Diffs are folded; open one to read it.

replies: 5people: 2as markdown or json

Stefan Beller· Jul 18, 2017, 00:20 UTC · lore

Remove hard coded sha1 values, obtain the values using 'git rev-parse HEAD' which should be future proof regardless of the hash function used.

Signed-off-by: Stefan Beller <sbeller@google.com>
---
 t/t8008-blame-formats.sh | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

Show changes to t/t8008-blame-formats.sh +15 −13

diff --git a/t/t8008-blame-formats.sh b/t/t8008-blame-formats.sh
index 92c8e792d1..49cac4b9af 100755
--- a/t/t8008-blame-formats.sh
+++ b/t/t8008-blame-formats.sh
@@ -12,22 +12,25 @@ test_expect_success 'setup' '
 	echo c >>file &&
 	echo d >>file &&
 	test_tick &&
-	git commit -a -m two
+	git commit -a -m two &&
+	ID1=$(git rev-parse HEAD^) &&
+	shortID1="^$(git rev-parse HEAD^ |cut -c 1-7)" &&
+	ID2=$(git rev-parse HEAD) &&
+	shortID2="$(git rev-parse HEAD |cut -c 1-8)"
 '
 
-cat >expect <<'EOF'
-^baf5e0b (A U Thor 2005-04-07 15:13:13 -0700 1) a
-8825379d (A U Thor 2005-04-07 15:14:13 -0700 2) b
-8825379d (A U Thor 2005-04-07 15:14:13 -0700 3) c
-8825379d (A U Thor 2005-04-07 15:14:13 -0700 4) d
+cat >expect <<EOF
+$shortID1 (A U Thor 2005-04-07 15:13:13 -0700 1) a
+$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 2) b
+$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 3) c
+$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 4) d
 EOF
 test_expect_success 'normal blame output' '
 	git blame file >actual &&
 	test_cmp expect actual
 '
 
-ID1=baf5e0b3869e0b2b2beb395a3720c7b51eac94fc
-COMMIT1='author A U Thor
+COMMIT1="author A U Thor
 author-mail <author@example.com>
 author-time 1112911993
 author-tz -0700
@@ -37,9 +40,8 @@ committer-time 1112911993
 committer-tz -0700
 summary one
 boundary
-filename file'
-ID2=8825379dfb8a1267b58e8e5bcf69eec838f685ec
-COMMIT2='author A U Thor
+filename file"
+COMMIT2="author A U Thor
 author-mail <author@example.com>
 author-time 1112912053
 author-tz -0700
@@ -48,8 +50,8 @@ committer-mail <committer@example.com>
 committer-time 1112912053
 committer-tz -0700
 summary two
-previous baf5e0b3869e0b2b2beb395a3720c7b51eac94fc file
-filename file'
+previous $ID1 file
+filename file"
 
 cat >expect <<EOF
 $ID1 1 1 1

-- 
2.13.3.650.g5ebc568d5d

Junio C Hamano· Jul 18, 2017, 19:17 UTC · re: Stefan Beller · lore

Re: [PATCH] t8008: rely on rev-parse'd HEAD instead of sha1 value

Stefan Beller <sbeller@google.com> writes:

> Remove hard coded sha1 values, obtain the values using 'git rev-parse HEAD'
> which should be future proof regardless of the hash function used.

Don't hardcoded lengths of the hashes defeat this future-proofing effort, though? It shouldn't be too hard to do the equivalent of the auto computation of abbreviation in this script, which would be true future-proofing, I guess.

Show 66 quoted lines

> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  t/t8008-blame-formats.sh | 28 +++++++++++++++-------------
>  1 file changed, 15 insertions(+), 13 deletions(-)
>
> diff --git a/t/t8008-blame-formats.sh b/t/t8008-blame-formats.sh
> index 92c8e792d1..49cac4b9af 100755
> --- a/t/t8008-blame-formats.sh
> +++ b/t/t8008-blame-formats.sh
> @@ -12,22 +12,25 @@ test_expect_success 'setup' '
>  	echo c >>file &&
>  	echo d >>file &&
>  	test_tick &&
> -	git commit -a -m two
> +	git commit -a -m two &&
> +	ID1=$(git rev-parse HEAD^) &&
> +	shortID1="^$(git rev-parse HEAD^ |cut -c 1-7)" &&
> +	ID2=$(git rev-parse HEAD) &&
> +	shortID2="$(git rev-parse HEAD |cut -c 1-8)"
>  '
>  
> -cat >expect <<'EOF'
> -^baf5e0b (A U Thor 2005-04-07 15:13:13 -0700 1) a
> -8825379d (A U Thor 2005-04-07 15:14:13 -0700 2) b
> -8825379d (A U Thor 2005-04-07 15:14:13 -0700 3) c
> -8825379d (A U Thor 2005-04-07 15:14:13 -0700 4) d
> +cat >expect <<EOF
> +$shortID1 (A U Thor 2005-04-07 15:13:13 -0700 1) a
> +$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 2) b
> +$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 3) c
> +$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 4) d
>  EOF
>  test_expect_success 'normal blame output' '
>  	git blame file >actual &&
>  	test_cmp expect actual
>  '
>  
> -ID1=baf5e0b3869e0b2b2beb395a3720c7b51eac94fc
> -COMMIT1='author A U Thor
> +COMMIT1="author A U Thor
>  author-mail <author@example.com>
>  author-time 1112911993
>  author-tz -0700
> @@ -37,9 +40,8 @@ committer-time 1112911993
>  committer-tz -0700
>  summary one
>  boundary
> -filename file'
> -ID2=8825379dfb8a1267b58e8e5bcf69eec838f685ec
> -COMMIT2='author A U Thor
> +filename file"
> +COMMIT2="author A U Thor
>  author-mail <author@example.com>
>  author-time 1112912053
>  author-tz -0700
> @@ -48,8 +50,8 @@ committer-mail <committer@example.com>
>  committer-time 1112912053
>  committer-tz -0700
>  summary two
> -previous baf5e0b3869e0b2b2beb395a3720c7b51eac94fc file
> -filename file'
> +previous $ID1 file
> +filename file"
>  
>  cat >expect <<EOF
>  $ID1 1 1 1

Stefan Beller· Jul 18, 2017, 19:22 UTC · re: Junio C Hamano · lore

Re: [PATCH] t8008: rely on rev-parse'd HEAD instead of sha1 value

On Tue, Jul 18, 2017 at 12:17 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 9 quoted lines

> Stefan Beller <sbeller@google.com> writes:
>
>> Remove hard coded sha1 values, obtain the values using 'git rev-parse HEAD'
>> which should be future proof regardless of the hash function used.
>
> Don't hardcoded lengths of the hashes defeat this future-proofing
> effort, though?  It shouldn't be too hard to do the equivalent of
> the auto computation of abbreviation in this script, which would be
> true future-proofing, I guess.

It depends on the definition of future proofing. My definition here only included the change of the hash function, not the change of display length in git-blame for a small artificial repo with 2 commits . These seem to be unrelated, so in case we'd change the length of the abbreviated displayed hash, we'd still want to have a test to tell us?

Junio C Hamano· Jul 18, 2017, 19:38 UTC · re: Stefan Beller · lore

Re: [PATCH] t8008: rely on rev-parse'd HEAD instead of sha1 value

Stefan Beller <sbeller@google.com> writes:

Show 17 quoted lines

> On Tue, Jul 18, 2017 at 12:17 PM, Junio C Hamano <gitster@pobox.com> wrote:
>> Stefan Beller <sbeller@google.com> writes:
>>
>>> Remove hard coded sha1 values, obtain the values using 'git rev-parse HEAD'
>>> which should be future proof regardless of the hash function used.
>>
>> Don't hardcoded lengths of the hashes defeat this future-proofing
>> effort, though?  It shouldn't be too hard to do the equivalent of
>> the auto computation of abbreviation in this script, which would be
>> true future-proofing, I guess.
>
> It depends on the definition of future proofing.
> My definition here only included the change of the hash function,
> not the change of display length in git-blame for a small artificial repo
> with 2 commits . These seem to be unrelated, so in case we'd change
> the length of the abbreviated displayed hash, we'd still want to have
> a test to tell us?

The thing is that depending on how these 2 commits hash and share prefixes, the length needed to disambiguate changes.

Stefan Beller· Jul 26, 2017, 19:06 UTC · re: Junio C Hamano · lore

[PATCHv2] t8008: rely on rev-parse'd HEAD instead of sha1 value

Remove hard coded sha1 values, obtain the values using 'git rev-parse HEAD' which should be future proof regardless of the hash function used.

Additionally future-proof the test by hard coding the abbreviation length of the hash.

Signed-off-by: Stefan Beller <sbeller@google.com>
---

> Don't hardcoded lengths of the hashes defeat this future-proofing
> effort, though?  It shouldn't be too hard to do the equivalent of
> the auto computation of abbreviation in this script, which would be
> true future-proofing, I guess.

Added --abbrev=n to also hard code hash abbreviation. At first I had the impression of a off-by-one-error, but after reading the man page for both blame and rev-parse, I realize that blames abbrev notion is different than rev-parse precisely for the caret that may occur to indicate out-of-range.

 t/t8008-blame-formats.sh | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

Show changes to t/t8008-blame-formats.sh +16 −14

diff --git a/t/t8008-blame-formats.sh b/t/t8008-blame-formats.sh
index 92c8e792d1..ae4b579d24 100755
--- a/t/t8008-blame-formats.sh
+++ b/t/t8008-blame-formats.sh
@@ -12,22 +12,25 @@ test_expect_success 'setup' '
 	echo c >>file &&
 	echo d >>file &&
 	test_tick &&
-	git commit -a -m two
+	git commit -a -m two &&
+	ID1=$(git rev-parse HEAD^) &&
+	shortID1="^$(git rev-parse HEAD^ |cut -c 1-17)" &&
+	ID2=$(git rev-parse HEAD) &&
+	shortID2="$(git rev-parse HEAD |cut -c 1-18)"
 '
 
-cat >expect <<'EOF'
-^baf5e0b (A U Thor 2005-04-07 15:13:13 -0700 1) a
-8825379d (A U Thor 2005-04-07 15:14:13 -0700 2) b
-8825379d (A U Thor 2005-04-07 15:14:13 -0700 3) c
-8825379d (A U Thor 2005-04-07 15:14:13 -0700 4) d
+cat >expect <<EOF
+$shortID1 (A U Thor 2005-04-07 15:13:13 -0700 1) a
+$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 2) b
+$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 3) c
+$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 4) d
 EOF
 test_expect_success 'normal blame output' '
-	git blame file >actual &&
+	git blame --abbrev=17 file >actual &&
 	test_cmp expect actual
 '
 
-ID1=baf5e0b3869e0b2b2beb395a3720c7b51eac94fc
-COMMIT1='author A U Thor
+COMMIT1="author A U Thor
 author-mail <author@example.com>
 author-time 1112911993
 author-tz -0700
@@ -37,9 +40,8 @@ committer-time 1112911993
 committer-tz -0700
 summary one
 boundary
-filename file'
-ID2=8825379dfb8a1267b58e8e5bcf69eec838f685ec
-COMMIT2='author A U Thor
+filename file"
+COMMIT2="author A U Thor
 author-mail <author@example.com>
 author-time 1112912053
 author-tz -0700
@@ -48,8 +50,8 @@ committer-mail <committer@example.com>
 committer-time 1112912053
 committer-tz -0700
 summary two
-previous baf5e0b3869e0b2b2beb395a3720c7b51eac94fc file
-filename file'
+previous $ID1 file
+filename file"
 
 cat >expect <<EOF
 $ID1 1 1 1

-- 
2.14.0.rc0.3.g6c2e499285

Junio C Hamano· Jul 26, 2017, 20:32 UTC · re: Stefan Beller · lore

Re: [PATCHv2] t8008: rely on rev-parse'd HEAD instead of sha1 value

Stefan Beller <sbeller@google.com> writes:

Show 20 quoted lines

> Remove hard coded sha1 values, obtain the values using
> 'git rev-parse HEAD' which should be future proof regardless
> of the hash function used.
>
> Additionally future-proof the test by hard coding the
> abbreviation length of the hash.
>
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>
>> Don't hardcoded lengths of the hashes defeat this future-proofing
>> effort, though?  It shouldn't be too hard to do the equivalent of
>> the auto computation of abbreviation in this script, which would be
>> true future-proofing, I guess.
>
> Added --abbrev=n to also hard code hash abbreviation. At first
> I had the impression of a off-by-one-error, but after reading the
> man page for both blame and rev-parse, I realize that blames
> abbrev notion is different than rev-parse precisely for the
> caret that may occur to indicate out-of-range.

OK, and 17 hexdigits ought to be sufficient for a sample repository we create for the test---we shouldn't be picking a hash that would cause hash prefix collisions with such a small number of objects and reasonably long prefix anyway ;-)

Thanks, will queue.

Show 66 quoted lines

>
>  t/t8008-blame-formats.sh | 30 ++++++++++++++++--------------
>  1 file changed, 16 insertions(+), 14 deletions(-)
>
> diff --git a/t/t8008-blame-formats.sh b/t/t8008-blame-formats.sh
> index 92c8e792d1..ae4b579d24 100755
> --- a/t/t8008-blame-formats.sh
> +++ b/t/t8008-blame-formats.sh
> @@ -12,22 +12,25 @@ test_expect_success 'setup' '
>  	echo c >>file &&
>  	echo d >>file &&
>  	test_tick &&
> -	git commit -a -m two
> +	git commit -a -m two &&
> +	ID1=$(git rev-parse HEAD^) &&
> +	shortID1="^$(git rev-parse HEAD^ |cut -c 1-17)" &&
> +	ID2=$(git rev-parse HEAD) &&
> +	shortID2="$(git rev-parse HEAD |cut -c 1-18)"
>  '
>  
> -cat >expect <<'EOF'
> -^baf5e0b (A U Thor 2005-04-07 15:13:13 -0700 1) a
> -8825379d (A U Thor 2005-04-07 15:14:13 -0700 2) b
> -8825379d (A U Thor 2005-04-07 15:14:13 -0700 3) c
> -8825379d (A U Thor 2005-04-07 15:14:13 -0700 4) d
> +cat >expect <<EOF
> +$shortID1 (A U Thor 2005-04-07 15:13:13 -0700 1) a
> +$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 2) b
> +$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 3) c
> +$shortID2 (A U Thor 2005-04-07 15:14:13 -0700 4) d
>  EOF
>  test_expect_success 'normal blame output' '
> -	git blame file >actual &&
> +	git blame --abbrev=17 file >actual &&
>  	test_cmp expect actual
>  '
>  
> -ID1=baf5e0b3869e0b2b2beb395a3720c7b51eac94fc
> -COMMIT1='author A U Thor
> +COMMIT1="author A U Thor
>  author-mail <author@example.com>
>  author-time 1112911993
>  author-tz -0700
> @@ -37,9 +40,8 @@ committer-time 1112911993
>  committer-tz -0700
>  summary one
>  boundary
> -filename file'
> -ID2=8825379dfb8a1267b58e8e5bcf69eec838f685ec
> -COMMIT2='author A U Thor
> +filename file"
> +COMMIT2="author A U Thor
>  author-mail <author@example.com>
>  author-time 1112912053
>  author-tz -0700
> @@ -48,8 +50,8 @@ committer-mail <committer@example.com>
>  committer-time 1112912053
>  committer-tz -0700
>  summary two
> -previous baf5e0b3869e0b2b2beb395a3720c7b51eac94fc file
> -filename file'
> +previous $ID1 file
> +filename file"
>  
>  cat >expect <<EOF
>  $ID1 1 1 1