admin/git
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
65d33db48e5a2c6dbf3f33d6eaa987f55dabe26a
git/t/t4053-diff-no-index.sh
Jacob Keller 09fb155f11 diff --no-index: support limiting by pathspec 
The --no-index option of git-diff enables using the diff machinery from
git while operating outside of a repository. This mode of git diff is
able to compare directories and produce a diff of their contents.

When operating git diff in a repository, git has the notion of
"pathspecs" which can specify which files to compare. In particular,
when using git to diff two trees, you might invoke:

  $ git diff-tree -r <treeish1> <treeish2>.

where the treeish could point to a subdirectory of the repository.

When invoked this way, users can limit the selected paths of the tree by
using a pathspec. Either by providing some list of paths to accept, or
by removing paths via a negative refspec.

The git diff --no-index mode does not support pathspecs, and cannot
limit the diff output in this way. Other diff programs such as GNU
difftools have options for excluding paths based on a pattern match.
However, using git diff as a diff replacement has several advantages
over many popular diff tools, including coloring moved lines, rename
detections, and similar.

Teach git diff --no-index how to handle pathspecs to limit the
comparisons. This will only be supported if both provided paths are
directories.

For comparisons where one path isn't a directory, the --no-index mode
already has some DWIM shortcuts implemented in the fixup_paths()
function.

Modify the fixup_paths function to return 1 if both paths are
directories. If this is the case, interpret any extra arguments to git
diff as pathspecs via parse_pathspec.

Use parse_pathspec to load the remaining arguments (if any) to git diff
--no-index as pathspec items. Disable PATHSPEC_ATTR support since we do
not have a repository to do attribute lookup. Disable PATHSPEC_FROMTOP
since we do not have a repository root. All pathspecs are treated as
rooted at the provided comparison paths.

After loading the pathspec data, calculate skip offsets for skipping
past the root portion of the paths. This is required to ensure that
pathspecs start matching from the provided path, rather than matching
from the absolute path. We could instead pass the paths as prefix values
to parse_pathspec. This is slightly problematic because the paths come
from the command line and don't necessarily have the proper trailing
slash. Additionally, that would require parsing pathspecs multiple
times.

Pass the pathspec object and the skip offsets into queue_diff, which
in-turn must pass them along to read_directory_contents.

Modify read_directory_contents to check against the pathspecs when
scanning the directory. Use the skip offset to skip past the initial
root of the path, and only match against portions that are below the
intended directory structure being compared.

The search algorithm for finding paths is recursive with read_dir. To
make pathspec matching work properly, we must set both
DO_MATCH_DIRECTORY and DO_MATCH_LEADING_PATHSPEC.

Without DO_MATCH_DIRECTORY, paths like "a/b/c/d" will not match against
pathspecs like "a/b/c". This is usually achieved by setting the is_dir
parameter of match_pathspec.

Without DO_MATCH_LEADING_PATHSPEC, paths like "a/b/c" would not match
against pathspecs like "a/b/c/d". This is crucial because we recursively
iterate down the directories. We could simply avoid checking pathspecs
at subdirectories, but this would force recursion down directories
which would simply be skipped.

If we always passed DO_MATCH_LEADING_PATHSPEC, then we will
incorrectly match in certain cases such as matching 'a/c' against
':(glob)**/d'. The match logic will see that a matches the leading part
of the **/ and accept this even tho c doesn't match.

To avoid this, use the match_leading_pathspec() variant recently
introduced. This sets both flags when is_dir is set, but leaves them
both cleared when is_dir is 0.

Add test cases and documentation covering the new functionality. Note
for the documentation I opted not to move the placement of '--' which is
sometimes used to disambiguate arguments. The diff --no-index mode
requires exactly 2 arguments determining what to compare. Any additional
arguments are interpreted as pathspecs and must come afterwards. Use of
'--' would not actually disambiguate anything, since there will never be
ambiguity over which arguments represent paths or pathspecs.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-22 14:20:11 -07:00

374 lines
9.5 KiB
Bash
Executable File
Raw Blame History

#!/bin/sh
test_description='diff --no-index'
. ./test-lib.sh
test_expect_success 'setup' '
mkdir a &&
mkdir b &&
echo 1 >a/1 &&
echo 2 >a/2 &&
git init repo &&
echo 1 >repo/a &&
mkdir -p non/git &&
echo 1 >non/git/a &&
echo 1 >non/git/b
'
test_expect_success 'git diff --no-index --exit-code' '
git diff --no-index --exit-code a/1 non/git/a &&
test_expect_code 1 git diff --no-index --exit-code a/1 a/2
'
test_expect_success 'git diff --no-index directories' '
test_expect_code 1 git diff --no-index a b >cnt &&
test_line_count = 14 cnt
'
test_expect_success 'git diff --no-index relative path outside repo' '
(
cd repo &&
test_expect_code 0 git diff --no-index a ../non/git/a &&
test_expect_code 0 git diff --no-index ../non/git/a ../non/git/b
)
'
test_expect_success 'git diff --no-index with broken index' '
(
cd repo &&
echo broken >.git/index &&
git diff --no-index a ../non/git/a
)
'
test_expect_success 'git diff outside repo with broken index' '
(
cd repo &&
git diff ../non/git/a ../non/git/b
)
'
test_expect_success 'git diff --no-index executed outside repo gives correct error message' '
(
GIT_CEILING_DIRECTORIES=$TRASH_DIRECTORY/non &&
export GIT_CEILING_DIRECTORIES &&
cd non/git &&
test_must_fail git diff --no-index a 2>actual.err &&
test_grep "usage: git diff --no-index" actual.err
)
'
test_expect_success 'diff D F and diff F D' '
(
cd repo &&
echo in-repo >a &&
echo non-repo >../non/git/a &&
mkdir sub &&
echo sub-repo >sub/a &&
test_must_fail git diff --no-index sub/a ../non/git/a >expect &&
test_must_fail git diff --no-index sub/a ../non/git/ >actual &&
test_cmp expect actual &&
test_must_fail git diff --no-index a ../non/git/a >expect &&
test_must_fail git diff --no-index a ../non/git/ >actual &&
test_cmp expect actual &&
test_must_fail git diff --no-index ../non/git/a a >expect &&
test_must_fail git diff --no-index ../non/git a >actual &&
test_cmp expect actual
)
'
test_expect_success 'turning a file into a directory' '
(
cd non/git &&
mkdir d e e/sub &&
echo 1 >d/sub &&
echo 2 >e/sub/file &&
printf "D\td/sub\nA\te/sub/file\n" >expect &&
test_must_fail git diff --no-index --name-status d e >actual &&
test_cmp expect actual
)
'
test_expect_success 'diff from repo subdir shows real paths (explicit)' '
echo "diff --git a/../../non/git/a b/../../non/git/b" >expect &&
test_expect_code 1 \
git -C repo/sub \
diff --no-index ../../non/git/a ../../non/git/b >actual &&
head -n 1 <actual >actual.head &&
test_cmp expect actual.head
'
test_expect_success 'diff from repo subdir shows real paths (implicit)' '
echo "diff --git a/../../non/git/a b/../../non/git/b" >expect &&
test_expect_code 1 \
git -C repo/sub \
diff ../../non/git/a ../../non/git/b >actual &&
head -n 1 <actual >actual.head &&
test_cmp expect actual.head
'
test_expect_success 'diff --no-index from repo subdir respects config (explicit)' '
echo "diff --git ../../non/git/a ../../non/git/b" >expect &&
test_config -C repo diff.noprefix true &&
test_expect_code 1 \
git -C repo/sub \
diff --no-index ../../non/git/a ../../non/git/b >actual &&
head -n 1 <actual >actual.head &&
test_cmp expect actual.head
'
test_expect_success 'diff --no-index from repo subdir respects config (implicit)' '
echo "diff --git ../../non/git/a ../../non/git/b" >expect &&
test_config -C repo diff.noprefix true &&
test_expect_code 1 \
git -C repo/sub \
diff ../../non/git/a ../../non/git/b >actual &&
head -n 1 <actual >actual.head &&
test_cmp expect actual.head
'
test_expect_success 'diff --no-index from repo subdir with absolute paths' '
cat <<-EOF >expect &&
1 1 $(pwd)/non/git/{a => b}
EOF
test_expect_code 1 \
git -C repo/sub diff --numstat \
"$(pwd)/non/git/a" "$(pwd)/non/git/b" >actual &&
test_cmp expect actual
'
test_expect_success 'diff --no-index allows external diff' '
test_expect_code 1 \
env GIT_EXTERNAL_DIFF="echo external ;:" \
git diff --no-index non/git/a non/git/b >actual &&
echo external >expect &&
test_cmp expect actual
'
test_expect_success 'diff --no-index normalizes mode: no changes' '
echo foo >x &&
cp x y &&
git diff --no-index x y >out &&
test_must_be_empty out
'
test_expect_success POSIXPERM 'diff --no-index normalizes mode: chmod +x' '
chmod +x y &&
cat >expected <<-\EOF &&
diff --git a/x b/y
old mode 100644
new mode 100755
EOF
test_expect_code 1 git diff --no-index x y >actual &&
test_cmp expected actual
'
test_expect_success POSIXPERM 'diff --no-index normalizes: mode not like git mode' '
chmod 666 x &&
chmod 777 y &&
cat >expected <<-\EOF &&
diff --git a/x b/y
old mode 100644
new mode 100755
EOF
test_expect_code 1 git diff --no-index x y >actual &&
test_cmp expected actual
'
test_expect_success POSIXPERM,SYMLINKS 'diff --no-index normalizes: mode not like git mode (symlink)' '
ln -s y z &&
X_OID=$(git hash-object --stdin <x) &&
Z_OID=$(printf y | git hash-object --stdin) &&
cat >expected <<-EOF &&
diff --git a/x b/x
deleted file mode 100644
index $X_OID..$ZERO_OID
--- a/x
+++ /dev/null
@@ -1 +0,0 @@
-foo
diff --git a/z b/z
new file mode 120000
index $ZERO_OID..$Z_OID
--- /dev/null
+++ b/z
@@ -0,0 +1 @@
+y
\ No newline at end of file
EOF
test_expect_code 1 git -c core.abbrev=no diff --no-index x z >actual &&
test_cmp expected actual
'
test_expect_success POSIXPERM 'external diff with mode-only change' '
echo content >not-executable &&
echo content >executable &&
chmod +x executable &&
echo executable executable $(test_oid zero) 100755 \
not-executable $(test_oid zero) 100644 not-executable \
>expect &&
test_expect_code 1 git -c diff.external=echo diff \
--no-index executable not-executable >actual &&
test_cmp expect actual
'
test_expect_success "diff --no-index treats '-' as stdin" '
cat >expect <<-EOF &&
diff --git a/- b/a/1
index $ZERO_OID..$(git hash-object --stdin <a/1) 100644
--- a/-
+++ b/a/1
@@ -1 +1 @@
-x
+1
EOF
test_write_lines x | test_expect_code 1 \
git -c core.abbrev=no diff --no-index -- - a/1 >actual &&
test_cmp expect actual &&
test_write_lines 1 | git diff --no-index -- a/1 - >actual &&
test_must_be_empty actual
'
test_expect_success "diff --no-index -R treats '-' as stdin" '
cat >expect <<-EOF &&
diff --git b/a/1 a/-
index $(git hash-object --stdin <a/1)..$ZERO_OID 100644
--- b/a/1
+++ a/-
@@ -1 +1 @@
-1
+x
EOF
test_write_lines x | test_expect_code 1 \
git -c core.abbrev=no diff --no-index -R -- - a/1 >actual &&
test_cmp expect actual &&
test_write_lines 1 | git diff --no-index -R -- a/1 - >actual &&
test_must_be_empty actual
'
test_expect_success 'diff --no-index refuses to diff stdin and a directory' '
test_must_fail git diff --no-index -- - a </dev/null 2>err &&
grep "fatal: cannot compare stdin to a directory" err
'
test_expect_success PIPE 'diff --no-index refuses to diff a named pipe and a directory' '
test_when_finished "rm -f pipe" &&
mkfifo pipe &&
test_must_fail git diff --no-index -- pipe a 2>err &&
grep "fatal: cannot compare a named pipe to a directory" err
'
test_expect_success PIPE,SYMLINKS 'diff --no-index reads from pipes' '
test_when_finished "rm -f old new new-link" &&
mkfifo old &&
mkfifo new &&
ln -s new new-link &&
{
(test_write_lines a b c >old) &
} &&
test_when_finished "kill $! || :" &&
{
(test_write_lines a x c >new) &
} &&
test_when_finished "kill $! || :" &&
cat >expect <<-EOF &&
diff --git a/old b/new-link
--- a/old
+++ b/new-link
@@ -1,3 +1,3 @@
a
-b
+x
c
EOF
test_expect_code 1 git diff --no-index old new-link >actual &&
test_cmp expect actual
'
test_expect_success 'diff --no-index F F rejects pathspecs' '
test_must_fail git diff --no-index -- a/1 a/2 a 2>actual.err &&
test_grep "usage: git diff --no-index" actual.err
'
test_expect_success 'diff --no-index D F rejects pathspecs' '
test_must_fail git diff --no-index -- a a/2 a 2>actual.err &&
test_grep "usage: git diff --no-index" actual.err
'
test_expect_success 'diff --no-index F D rejects pathspecs' '
test_must_fail git diff --no-index -- a/1 b b 2>actual.err &&
test_grep "usage: git diff --no-index" actual.err
'
test_expect_success 'diff --no-index rejects absolute pathspec' '
test_must_fail git diff --no-index -- a b $(pwd)/a/1
'
test_expect_success 'diff --no-index with pathspec' '
test_expect_code 1 git diff --name-status --no-index a b 1 >actual &&
cat >expect <<-EOF &&
D a/1
EOF
test_cmp expect actual
'
test_expect_success 'diff --no-index with pathspec no matches' '
test_expect_code 0 git diff --name-status --no-index a b missing
'
test_expect_success 'diff --no-index with negative pathspec' '
test_expect_code 1 git diff --name-status --no-index a b ":!2" >actual &&
cat >expect <<-EOF &&
D a/1
EOF
test_cmp expect actual
'
test_expect_success 'setup nested' '
mkdir -p c/1/2 &&
mkdir -p d/1/2 &&
echo 1 >c/1/2/a &&
echo 2 >c/1/2/b
'
test_expect_success 'diff --no-index with pathspec nested negative pathspec' '
test_expect_code 0 git diff --no-index c d ":!1"
'
test_expect_success 'diff --no-index with pathspec nested pathspec' '
test_expect_code 1 git diff --name-status --no-index c d 1/2 >actual &&
cat >expect <<-EOF &&
D c/1/2/a
D c/1/2/b
EOF
test_cmp expect actual
'
test_expect_success 'diff --no-index with pathspec glob' '
test_expect_code 1 git diff --name-status --no-index c d ":(glob)**/a" >actual &&
cat >expect <<-EOF &&
D c/1/2/a
EOF
test_cmp expect actual
'
test_expect_success 'diff --no-index with pathspec glob and exclude' '
test_expect_code 1 git diff --name-status --no-index c d ":(glob,exclude)**/a" >actual &&
cat >expect <<-EOF &&
D c/1/2/b
EOF
test_cmp expect actual
'
test_done
Reference in New Issue View Git Blame Copy Permalink