Hi Michał,

On Mon, 12 Oct 2020, Michał Kępień wrote:

> Exercise the new -I<regex> diff option in various scenarios to ensure it
> behaves as expected.

Excellent. I was actually looking for a test in patch 2/3 and almost
commented about that.

>
> Signed-off-by: Michał Kępień <michal@isc.org>
> ---
>  t/t4069-diff-ignore-regex.sh | 426 +++++++++++++++++++++++++++++++++++

Hmm. I wonder whether we could do with a much more concise test script.
The test suite already takes a quite long time to run, which is not a
laughing matter: we had issues in the past where contributors would skip
running it because it took too long, and this test is sure to exacerbate
that problem.

I could imagine, for example, that it would be plenty enough to do
something like this instead:

-- snip --
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 5c7b0122b4f..bf158be137f 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -6,6 +6,7 @@
 test_description='Various diff formatting options'

 . ./test-lib.sh
+. "$TEST_DIRECTORY"/diff-lib.sh

 test_expect_success setup '

@@ -473,4 +474,24 @@ test_expect_success 'diff-tree --stdin with log formatting' '
 	test_cmp expect actual
 '

+test_expect_success '-I<regex>' '
+	seq 50 >I.txt &&
+	sed -e "s/13/ten and three/" -e "/7\$/d" <I.txt >J.txt &&
+	test_must_fail git diff --no-index -I"ten.*e" -I"^[124-9]" I.txt J.txt >actual &&
+	cat >expect <<-\EOF &&
+	diff --git a/I.txt b/J.txt
+	--- a/I.txt
+	+++ b/J.txt
+	@@ -34,7 +31,6 @@
+	 34
+	 35
+	 36
+	-37
+	 38
+	 39
+	 40
+	EOF
+	compare_diff_patch expect actual
+'
+
 test_done
-- snap --

Note how it tests various things in one go?

Thanks,
Dscho

P.S.: My main interest in the `-I` option is its use case for `git
range-diff` in Git's own context: if you want to compare your patches to
what entered the `seen` branch, there will _always_ be a difference
because Junio adds their DCO. Something like this can help that:

git range-diff \
	-I'^    Signed-off-by: Junio C Hamano <gitster@pobox.com>$' \
	<my-patch-range> <the-equivalent-in-seen>

>  1 file changed, 426 insertions(+)
>  create mode 100755 t/t4069-diff-ignore-regex.sh
>
> diff --git a/t/t4069-diff-ignore-regex.sh b/t/t4069-diff-ignore-regex.sh
> new file mode 100755
> index 0000000000..4ddf5c67ae
> --- /dev/null
> +++ b/t/t4069-diff-ignore-regex.sh
> @@ -0,0 +1,426 @@
> +#!/bin/sh
> +
> +test_description='Test diff -I<regex>'
> +
> +. ./test-lib.sh
> +. "$TEST_DIRECTORY"/diff-lib.sh
> +
> +test_expect_success setup '
> +	test_seq 20 >x &&
> +	git update-index --add x
> +'
> +
> +test_expect_success 'one line changed' '
> +	test_seq 20 | sed "s/10/100/" >x &&
> +
> +	# Get plain diff
> +	git diff >plain &&
> +	cat >expected <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -7,7 +7,7 @@
> +	 7
> +	 8
> +	 9
> +	-10
> +	+100
> +	 11
> +	 12
> +	 13
> +	EOF
> +	compare_diff_patch expected plain &&
> +
> +	# Both old and new line match regex - ignore change
> +	git diff -I "^10" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Both old and new line match some regex - ignore change
> +	git diff -I "^10\$" -I "^100" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Only old line matches regex - do not ignore change
> +	git diff -I "^10\$" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# Only new line matches regex - do not ignore change
> +	git diff -I "^100" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# Only old line matches some regex - do not ignore change
> +	git diff -I "^10\$" -I "^101" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# Only new line matches some regex - do not ignore change
> +	git diff -I "^11\$" -I "^100" >actual &&
> +	compare_diff_patch plain actual
> +'
> +
> +test_expect_success 'one line removed' '
> +	test_seq 20 | sed "10d" >x &&
> +
> +	# Get plain diff
> +	git diff >plain &&
> +	cat >expected <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -7,7 +7,6 @@
> +	 7
> +	 8
> +	 9
> +	-10
> +	 11
> +	 12
> +	 13
> +	EOF
> +	compare_diff_patch expected plain &&
> +
> +	# Removed line matches regex - ignore change
> +	git diff -I "^10" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Removed line matches some regex - ignore change
> +	git diff -I "^10" -I "^100" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Removed line does not match regex - do not ignore change
> +	git diff -I "^101" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# Removed line does not match any regex - do not ignore change
> +	git diff -I "^100" -I "^101" >actual &&
> +	compare_diff_patch plain actual
> +'
> +
> +test_expect_success 'one line added' '
> +	test_seq 21 >x &&
> +
> +	# Get plain diff
> +	git diff >plain &&
> +	cat >expected <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -18,3 +18,4 @@
> +	 18
> +	 19
> +	 20
> +	+21
> +	EOF
> +	compare_diff_patch expected plain &&
> +
> +	# Added line matches regex - ignore change
> +	git diff -I "^21" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Added line matches some regex - ignore change
> +	git diff -I "^21" -I "^22" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Added line does not match regex - do not ignore change
> +	git diff -I "^212" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# Added line does not match any regex - do not ignore change
> +	git diff -I "^211" -I "^212" >actual &&
> +	compare_diff_patch plain actual
> +'
> +
> +test_expect_success 'last two lines changed' '
> +	test_seq 20 | sed "s/19/21/; s/20/22/" >x &&
> +
> +	# Get plain diff
> +	git diff >plain &&
> +	cat >expected <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -16,5 +16,5 @@
> +	 16
> +	 17
> +	 18
> +	-19
> +	-20
> +	+21
> +	+22
> +	EOF
> +	compare_diff_patch expected plain &&
> +
> +	# All changed lines match regex - ignore change
> +	git diff -I "^[12]" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# All changed lines match some regex - ignore change
> +	git diff -I "^1" -I "^2" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Not all changed lines match regex - do not ignore change
> +	git diff -I "^2" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# Not all changed lines match some regex - do not ignore change
> +	git diff -I "^2" -I "^3" >actual &&
> +	compare_diff_patch plain actual
> +'
> +
> +test_expect_success 'two non-adjacent lines removed in the same hunk' '
> +	test_seq 20 | sed "1d; 3d" >x &&
> +
> +	# Get plain diff
> +	git diff >plain &&
> +	cat >expected <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -1,6 +1,4 @@
> +	-1
> +	 2
> +	-3
> +	 4
> +	 5
> +	 6
> +	EOF
> +	compare_diff_patch expected plain &&
> +
> +	# Both removed lines match regex - ignore hunk
> +	git diff -I "^[1-3]" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Both removed lines match some regex - ignore hunk
> +	git diff -I "^1" -I "^3" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# First removed line does not match regex - do not ignore hunk
> +	git diff -I "^[2-3]" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# First removed line does not match any regex - do not ignore hunk
> +	git diff -I "^2" -I "^3" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# Second removed line does not match regex - do not ignore hunk
> +	git diff -I "^[1-2]" >actual &&
> +	compare_diff_patch plain actual &&
> +
> +	# Second removed line does not match any regex - do not ignore hunk
> +	git diff -I "^1" -I "^2" >actual &&
> +	compare_diff_patch plain actual
> +'
> +
> +test_expect_success 'two non-adjacent lines removed in the same hunk, with -U1' '
> +	test_seq 20 | sed "1d; 3d" >x &&
> +
> +	# Get plain diff
> +	git diff -U1 >plain &&
> +	cat >expected <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -1,4 +1,2 @@
> +	-1
> +	 2
> +	-3
> +	 4
> +	EOF
> +	compare_diff_patch expected plain &&
> +
> +	# Both removed lines match regex - ignore hunk
> +	git diff -U1 -I "^[1-3]" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Both removed lines match some regex - ignore hunk
> +	git diff -U1 -I "^1" -I "^3" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# First removed line does not match regex, but is out of context - ignore second change
> +	git diff -U1 -I "^[2-3]" >actual &&
> +	cat >second-change-ignored <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -1,2 +1 @@
> +	-1
> +	 2
> +	EOF
> +	compare_diff_patch second-change-ignored actual &&
> +
> +	# First removed line does not match any regex, but is out of context - ignore second change
> +	git diff -U1 -I "^2" -I "^3" >actual &&
> +	compare_diff_patch second-change-ignored actual &&
> +
> +	# Second removed line does not match regex, but is out of context - ignore first change
> +	git diff -U1 -I "^[1-2]" >actual &&
> +	cat >first-change-ignored <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -2,3 +1,2 @@
> +	 2
> +	-3
> +	 4
> +	EOF
> +	compare_diff_patch first-change-ignored actual &&
> +
> +	# Second removed line does not match any regex, but is out of context - ignore first change
> +	git diff -U1 -I "^1" -I "^2" >actual &&
> +	compare_diff_patch first-change-ignored actual
> +'
> +
> +test_expect_success 'multiple hunks' '
> +	test_seq 20 | sed "1d; 20d" >x &&
> +
> +	# Get plain diff
> +	git diff >plain &&
> +	cat >expected <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -1,4 +1,3 @@
> +	-1
> +	 2
> +	 3
> +	 4
> +	@@ -17,4 +16,3 @@
> +	 17
> +	 18
> +	 19
> +	-20
> +	EOF
> +	compare_diff_patch expected plain &&
> +
> +	# Ignore both hunks (single regex)
> +	git diff -I "^[12]" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Ignore both hunks (multiple regexes)
> +	git diff -I "^1" -I "^2" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Only ignore first hunk (single regex)
> +	git diff -I "^1" >actual &&
> +	cat >first-hunk-ignored <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -17,4 +16,3 @@
> +	 17
> +	 18
> +	 19
> +	-20
> +	EOF
> +	compare_diff_patch first-hunk-ignored actual &&
> +
> +	# Only ignore first hunk (multiple regexes)
> +	git diff -I "^0" -I "^1" >actual &&
> +	compare_diff_patch first-hunk-ignored actual &&
> +
> +	# Only ignore second hunk (single regex)
> +	git diff -I "^2" >actual &&
> +	cat >second-hunk-ignored <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -1,4 +1,3 @@
> +	-1
> +	 2
> +	 3
> +	 4
> +	EOF
> +	compare_diff_patch second-hunk-ignored actual &&
> +
> +	# Only ignore second hunk (multiple regexes)
> +	git diff -I "^2" -I "^3" >actual &&
> +	compare_diff_patch second-hunk-ignored actual
> +'
> +
> +test_expect_success 'multiple hunks, with --ignore-blank-lines' '
> +	echo >x &&
> +	test_seq 21 >>x &&
> +
> +	# Get plain diff
> +	git diff >plain &&
> +	cat >expected <<-EOF &&
> +	diff --git a/x b/x
> +	--- a/x
> +	+++ b/x
> +	@@ -1,3 +1,4 @@
> +	+
> +	 1
> +	 2
> +	 3
> +	@@ -18,3 +19,4 @@
> +	 18
> +	 19
> +	 20
> +	+21
> +	EOF
> +	compare_diff_patch expected plain &&
> +
> +	# -I does not override --ignore-blank-lines - ignore both hunks (single regex)
> +	git diff --ignore-blank-lines -I "^21" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# -I does not override --ignore-blank-lines - ignore both hunks (multiple regexes)
> +	git diff --ignore-blank-lines -I "^21" -I "^12" >actual &&
> +	test_must_be_empty actual
> +'
> +
> +test_expect_success 'diffstat' '
> +	test_seq 20 | sed "s/^5/0/p; s/^15/10/; 16d" >x &&
> +
> +	# Get plain diffstat
> +	git diff --stat >actual &&
> +	cat >expected <<-EOF &&
> +	 x | 6 +++---
> +	 1 file changed, 3 insertions(+), 3 deletions(-)
> +	EOF
> +	test_cmp expected actual &&
> +
> +	# Ignore both hunks (single regex)
> +	git diff --stat -I "^[0-5]" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Ignore both hunks (multiple regexes)
> +	git diff --stat -I "^0" -I "^1" -I "^5" >actual &&
> +	test_must_be_empty actual &&
> +
> +	# Only ignore first hunk (single regex)
> +	git diff --stat -I "^[05]" >actual &&
> +	cat >expected <<-EOF &&
> +	 x | 3 +--
> +	 1 file changed, 1 insertion(+), 2 deletions(-)
> +	EOF
> +	test_cmp expected actual &&
> +
> +	# Only ignore first hunk (multiple regexes)
> +	git diff --stat -I "^0" -I "^5" >actual &&
> +	test_cmp expected actual &&
> +
> +	# Only ignore second hunk (single regex)
> +	git diff --stat -I "^1" >actual &&
> +	cat >expected <<-EOF &&
> +	 x | 3 ++-
> +	 1 file changed, 2 insertions(+), 1 deletion(-)
> +	EOF
> +	test_cmp expected actual &&
> +
> +	# Only ignore second hunk (multiple regexes)
> +	git diff --stat -I "^1" -I "^2" >actual &&
> +	test_cmp expected actual
> +'
> +
> +test_expect_success 'invalid regexes' '
> +	>x &&
> +
> +	# Single invalid regex
> +	git diff -I "^[1" 2>&1 | grep "invalid regex: " &&
> +
> +	# Two regexes: first invalid, second valid
> +	git diff -I "^[1" -I "^1" 2>&1 | grep "invalid regex: " &&
> +
> +	# Two invalid regexes
> +	git diff -I "^[1" -I "^[2" 2>&1 | grep "invalid regex: "
> +'
> +
> +test_done
> --
> 2.28.0
>
>