Re: [PATCH 00/10] Add the Git Change command

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Chris

On 23/09/2022 19:55, Christophe Poucet via GitGitGadget wrote:
> I'm reviving the original git evolve work that was started by
> sxenos@google.com
> (https://public-inbox.org/git/20190215043105.163688-1-sxenos@google.com/)
> 
> This work is intended to make it easier to deal with stacked changes.
> 
> The following set of patches introduces the design doc on the evolve command
> as well as the basics of the git change command.

Our test suite can be a little tricky to get started with and I was impatient to
check the basic functionality of these patches so I've written some simple
example tests for the change command and a couple of fixups to make them pass.

Best Wishes

Phillip

---- >8 ----

 From a7c38d0f388e4d8a1f3debcc3069a7fb43084eda Mon Sep 17 00:00:00 2001
From: Phillip Wood <phillip.wood@dunelm.org.uk>
Date: Tue, 4 Oct 2022 15:12:36 +0100
Subject: [PATCH 1/3] fixup! evolve: add support for writing metacommits

---
  metacommit.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/metacommit.c b/metacommit.c
index d2b859a4d3..8f970fa104 100644
--- a/metacommit.c
+++ b/metacommit.c
@@ -296,7 +296,7 @@ int record_metacommit_withresult(
         if (override_change) {
                 string_list_clear(changes, 0);
                 overridden_head = get_change_head(chtable, override_change);
-               if (!overridden_head) {
+               if (overridden_head) {
                         /* This is an existing change */
                         old_head = &overridden_head->head;
                         if (!force) {
-- 
2.37.3.947.g1b8ba4da7f.dirty


 From cc7e8ba0b1a90268ced85d3f0c91aed49f2246d6 Mon Sep 17 00:00:00 2001
From: Phillip Wood <phillip.wood@dunelm.org.uk>
Date: Tue, 4 Oct 2022 15:15:32 +0100
Subject: [PATCH 2/3] fixup! evolve: implement the git change command

---
  t/t9999-changes.sh | 126 +++++++++++++++++++++++++++++++++++++++++++++
  1 file changed, 126 insertions(+)
  create mode 100755 t/t9999-changes.sh

diff --git a/t/t9999-changes.sh b/t/t9999-changes.sh
new file mode 100755
index 0000000000..9e58925b23
--- /dev/null
+++ b/t/t9999-changes.sh
@@ -0,0 +1,126 @@
+#!/bin/sh
+
+test_description='git change - low level meta-commit management'
+
+. ./test-lib.sh
+
+. "$TEST_DIRECTORY"/lib-rebase.sh
+
+test_expect_success 'setup commits and meta-commits' '
+       for c in one two three
+       do
+               test_commit $c &&
+               git change update --content $c >actual 2>err &&
+               echo "Created change metas/$c" >expect &&
+               test_cmp expect actual &&
+               test_must_be_empty err &&
+               test_cmp_rev refs/metas/$c $c || return 1
+       done
+'
+
+# Check a meta-commit has the correct parents Call with the object
+# name of the meta-commit followed by pairs of type and parent
+check_meta_commit () {
+       name=$1
+       shift
+       while test $# -gt 0
+       do
+               printf '%s %s\n' $1 $(git rev-parse --verify $2)
+               shift
+               shift
+       done | sort >expect
+       git cat-file commit $name >metacommit &&
+       # commit body should consist of parent-type
+           types="$(sed -n '/^$/ {
+                       :loop
+                       n
+                       s/^parent-type //
+                       p
+                       b loop
+                   }' metacommit)" &&
+       while read key value
+       do
+               # TODO: don't sort the first parent
+               if test "$key" = "parent"
+               then
+                       type="${types%% *}"
+                       test -n "$type" || return 1
+                       printf '%s %s\n' $type $value
+                       types="${types#?}"
+                       types="${types# }"
+               elif test "$key" = "tree"
+               then
+                       test_cmp_rev "$value" $EMPTY_TREE || return 1
+               elif test -z "$key"
+               then
+                       # only parse commit headers
+                       break
+               fi
+       done <metacommit >actual-unsorted &&
+       test -z "$types" &&
+       sort >actual <actual-unsorted &&
+       test_cmp expect actual
+}
+
+test_expect_success 'update meta-commits after rebase' '
+       (
+               set_fake_editor &&
+               FAKE_AMEND=edited &&
+               FAKE_LINES="reword 1 pick 2 fixup 3" &&
+               export FAKE_AMEND FAKE_LINES &&
+               git rebase -i --root
+       ) &&
+
+       # update meta-commits
+       git change update --replace tags/one --content HEAD~1 >out 2>err &&
+       echo "Updated change metas/one" >expect &&
+       test_cmp expect out &&
+       test_must_be_empty err &&
+       git change update --replace tags/two --content HEAD@{2} &&
+       oid=$(git rev-parse --verify metas/two) &&
+       git change update --replace HEAD@{2} --replace tags/three \
+               --content HEAD &&
+
+       # check meta-commits
+       check_meta_commit metas/one c HEAD~1 r tags/one &&
+       check_meta_commit $oid c HEAD@{2} r tags/two &&
+       # NB this checks that "git change update" uses the meta-commit ($oid)
+       #    corresponding to the replaces commit (HEAD@2 above) given on the
+       #    commandline.
+       check_meta_commit metas/two c HEAD r $oid r tags/three &&
+       check_meta_commit metas/three c HEAD r $oid r tags/three
+'
+
+reset_meta_commits () {
+    for c in one two three
+    do
+       echo "update refs/metas/$c refs/tags/$c^0"
+    done | git update-ref --stdin
+}
+
+test_expect_success 'override change name' '
+       # TODO: builtin/change.c expects --change to be the full refname,
+       #       ideally it would prepend refs/metas to the string given by the
+       #       user.
+       git change update --change refs/metas/another-one --content one &&
+       test_cmp_rev metas/another-one one
+'
+
+test_expect_success 'non-fast forward meta-commit update refused' '
+       test_must_fail git change update --change refs/metas/one --content two \
+               >out 2>err &&
+       echo "error: non-fast-forward update to ${SQ}refs/metas/one${SQ}" \
+               >expect &&
+       test_cmp expect err &&
+       test_must_be_empty out
+'
+
+test_expect_success 'forced non-fast forward update succeeds' '
+       git change update --change refs/metas/one --content two --force \
+               >out 2>err &&
+       echo "Updated change metas/one" >expect &&
+       test_cmp expect out &&
+       test_must_be_empty err
+'
+
+test_done
-- 
2.37.3.947.g1b8ba4da7f.dirty


 From 7784f253fa799dd11fcbc81fe815fb387af52d97 Mon Sep 17 00:00:00 2001
From: Phillip Wood <phillip.wood@dunelm.org.uk>
Date: Tue, 4 Oct 2022 15:16:05 +0100
Subject: [PATCH 3/3] fixup! evolve: add the git change list command

---
  builtin/change.c   | 16 +++++-----------
  t/t9999-changes.sh | 11 +++++++++++
  2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/builtin/change.c b/builtin/change.c
index 07d029d82d..888ef648fa 100644
--- a/builtin/change.c
+++ b/builtin/change.c
@@ -34,9 +34,8 @@ static int change_list(int argc, const char **argv, const char* prefix)
                 OPT_END()
         };
         struct ref_filter filter;
-       /* TODO: See below
         struct ref_sorting *sorting;
-       struct string_list sorting_options = STRING_LIST_INIT_DUP; */
+       struct string_list sorting_options = STRING_LIST_INIT_DUP;
         struct ref_format format = REF_FORMAT_INIT;
         struct ref_array array;
         int i;
@@ -53,19 +52,15 @@ static int change_list(int argc, const char **argv, const char* prefix)
  
         filter_refs(&array, &filter, FILTER_REFS_CHANGES);
  
-       /* TODO: This causes a crash. It sets one of the atom_value handlers to
-        * something invalid, which causes a crash later when we call
-        * show_ref_array_item. Figure out why this happens and put back the sorting.
-        *
-        * sorting = ref_sorting_options(&sorting_options);
-        * ref_array_sort(sorting, &array); */
-
         if (!format.format)
                 format.format = "%(refname:lstrip=1)";
  
         if (verify_ref_format(&format))
                 die(_("unable to parse format string"));
  
+       sorting = ref_sorting_options(&sorting_options);
+       ref_array_sort(sorting, &array);
+
         for (i = 0; i < array.nr; i++) {
                 struct strbuf output = STRBUF_INIT;
                 struct strbuf err = STRBUF_INIT;
@@ -79,8 +74,7 @@ static int change_list(int argc, const char **argv, const char* prefix)
         }
  
         ref_array_clear(&array);
-       /* TODO: see above
-       ref_sorting_release(sorting); */
+       ref_sorting_release(sorting);
  
         return 0;
  }
diff --git a/t/t9999-changes.sh b/t/t9999-changes.sh
index 9e58925b23..9312eba86d 100755
--- a/t/t9999-changes.sh
+++ b/t/t9999-changes.sh
@@ -123,4 +123,15 @@ test_expect_success 'forced non-fast forward update succeeds' '
         test_must_be_empty err
  '
  
+test_expect_success 'list changes' '
+       cat >expect <<-\EOF &&
+       metas/another-one
+       metas/one
+       metas/three
+       metas/two
+       EOF
+       git change list >actual &&
+       test_cmp expect actual
+'
+
  test_done
-- 
2.37.3.947.g1b8ba4da7f.dirty