branch: add --dry-run for --delete-merged

"git branch --dry-run --delete-merged ..." prints one line per ref that
would be deleted without modifying refs or branch configuration.

--dry-run is only meaningful together with --delete-merged and is
rejected otherwise.

Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-branch.adoc b/Documentation/git-branch.adoc
index 2b206e8689ed3f5747b1c7bab925eaf761208301..51dda151142c66a49c506262372381535b65b92d 100644 (file)
--- a/Documentation/git-branch.adoc
+++ b/Documentation/git-branch.adoc
@@ -25,7 +25,7 @@ git branch (-m|-M) [<old-branch>] <new-branch>
 git branch (-c|-C) [<old-branch>] <new-branch>
 git branch (-d|-D) [-r] <branch-name>...
 git branch --edit-description [<branch-name>]
-git branch (--delete-merged <branch>)... [<pattern>...]
+git branch [--dry-run] (--delete-merged <branch>)... [<pattern>...]
 
 DESCRIPTION
 -----------
@@ -232,6 +232,12 @@ A branch that a surviving branch depends on through a chain of local
 upstreams is kept, so a branch is never deleted out from under stacked
 work.
 
+`--dry-run`::
+       With `--delete-merged`, print which branches would be
+       deleted and exit without touching any ref.  Useful for
+       sanity-checking a wide pattern like `'origin/*'` before
+       committing to the deletion.
+
 `-v`::
 `-vv`::
 `--verbose`::

diff --git a/builtin/branch.c b/builtin/branch.c
index 4644f061ea9b6e1a5da109bc3f1a652ad86503b5..fa8f3ee4dff90ee649524feffef53e761f07b0cd 100644 (file)
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -199,6 +199,7 @@ enum delete_branch_flags {
        DELETE_BRANCH_QUIET = (1 << 1),
        DELETE_BRANCH_SKIP_UNMERGED = (1 << 2),
        DELETE_BRANCH_NO_HEAD_FALLBACK = (1 << 3),
+       DELETE_BRANCH_DRY_RUN = (1 << 4),
 };
 
 static int check_branch_commit(const char *branchname, const char *refname,
@@ -340,13 +341,20 @@ static int delete_branches(int argc, const char **argv, int kinds,
                free(target);
        }
 
-       if (refs_delete_refs(get_main_ref_store(the_repository), NULL, &refs_to_delete, REF_NO_DEREF))
+       if (!(flags & DELETE_BRANCH_DRY_RUN) &&
+           refs_delete_refs(get_main_ref_store(the_repository), NULL, &refs_to_delete, REF_NO_DEREF))
                ret = 1;
 
        for_each_string_list_item(item, &refs_to_delete) {
                char *describe_ref = item->util;
                char *name = item->string;
-               if (!refs_ref_exists(get_main_ref_store(the_repository), name)) {
+               if (flags & DELETE_BRANCH_DRY_RUN) {
+                       if (!(flags & DELETE_BRANCH_QUIET))
+                               printf(remote_branch
+                                       ? _("Would delete remote-tracking branch %s (was %s).\n")
+                                       : _("Would delete branch %s (was %s).\n"),
+                                       name + branch_name_pos, describe_ref);
+               } else if (!refs_ref_exists(get_main_ref_store(the_repository), name)) {
                        char *refname = name + branch_name_pos;
                        if (!(flags & DELETE_BRANCH_QUIET))
                                printf(remote_branch
@@ -899,6 +907,7 @@ int cmd_branch(int argc,
        int delete = 0, rename = 0, copy = 0, list = 0,
            unset_upstream = 0, show_current = 0, edit_description = 0;
        struct strvec delete_merged = STRVEC_INIT;
+       int dry_run = 0;
        const char *new_upstream = NULL;
        int noncreate_actions = 0;
        /* possible options */
@@ -955,6 +964,8 @@ int cmd_branch(int argc,
                OPT_CALLBACK_F(0, "delete-merged", &delete_merged, N_("branch"),
                        N_("delete merged branches whose upstream matches <branch> (repeatable)"),
                        PARSE_OPT_NONEG, parse_opt_strvec),
+               OPT_BOOL(0, "dry-run", &dry_run,
+                       N_("with --delete-merged, only print which branches would be deleted")),
                OPT__FORCE(&force, N_("force creation, move/rename, deletion"), PARSE_OPT_NOCOMPLETE),
                OPT_MERGED(&filter, N_("print only branches that are merged")),
                OPT_NO_MERGED(&filter, N_("print only branches that are not merged")),
@@ -1017,6 +1028,9 @@ int cmd_branch(int argc,
        if (noncreate_actions > 1)
                usage_with_options(builtin_branch_usage, options);
 
+       if (dry_run && !delete_merged.nr)
+               die(_("--dry-run requires --delete-merged"));
+
        if (recurse_submodules_explicit) {
                if (!submodule_propagate_branches)
                        die(_("branch with --recurse-submodules can only be used if submodule.propagateBranches is enabled"));
@@ -1057,7 +1071,8 @@ int cmd_branch(int argc,
                goto out;
        } else if (delete_merged.nr) {
                ret = delete_merged_branches(&delete_merged, argv,
-                                            quiet ? DELETE_BRANCH_QUIET : 0);
+                                            (quiet ? DELETE_BRANCH_QUIET : 0) |
+                                            (dry_run ? DELETE_BRANCH_DRY_RUN : 0));
                goto out;
        } else if (show_current) {
                print_current_branch_name();

diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index e808e0dd09822b8843a8829212268eaffb6bc596..9327dbfbdd9616c66725de4029dca736cf4d93b1 100755 (executable)
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -1900,6 +1900,19 @@ test_expect_success '--delete-merged deletes only selected merged branches' '
                git checkout -b tracks-other other/main --track &&
                sha=$(git rev-parse --short merged) &&
 
+               git branch --dry-run --delete-merged origin/next merged >actual 2>&1 &&
+               echo "Would delete branch merged (was $sha)." >expect &&
+               test_cmp expect actual &&
+               git rev-parse --verify refs/heads/merged &&
+
+               check_branches <<-\EOF &&
+               also-merged
+               main
+               merged
+               tracks-other
+               unmerged
+               EOF
+
                git branch --delete-merged origin/next merged >actual 2>&1 &&
                echo "Deleted branch merged (was $sha)." >expect &&
                test_cmp expect actual &&
@@ -1948,9 +1961,12 @@ test_expect_success '--delete-merged keeps the upstream of a surviving branch' '
                git checkout -b topic feature --track &&
                git commit --allow-empty -m "topic work" &&
 
-               git branch --delete-merged origin/next 2>err &&
+               git branch --dry-run --delete-merged origin/next >out &&
+               test_grep ! "feature" out &&
 
+               git branch --delete-merged origin/next 2>err &&
                test_must_be_empty err &&
+
                check_branches <<-\EOF &&
                feature
                main
@@ -1978,6 +1994,21 @@ test_expect_success '--delete-merged keeps the upstream chain of a surviving bra
                git checkout -b tip mid --track &&
                git commit --allow-empty -m "tip work" &&
 
+               git branch --dry-run --delete-merged origin/next \
+                       --delete-merged lower >actual 2>&1 &&
+               test_must_be_empty actual &&
+
+               git config --local --get-regexp "branch\\.(lower|mid|tip)\\.(merge|remote)" >actual &&
+               cat >expect <<-\EOF &&
+               branch.lower.remote origin
+               branch.lower.merge refs/heads/next
+               branch.mid.remote .
+               branch.mid.merge refs/heads/lower
+               branch.tip.remote .
+               branch.tip.merge refs/heads/mid
+               EOF
+               test_cmp expect actual &&
+
                git branch --delete-merged origin/next \
                        --delete-merged lower >actual 2>&1 &&
                test_must_be_empty actual &&
@@ -2074,4 +2105,9 @@ test_expect_success "branch -d still deletes a deleteMerged=false branch" '
        )
 '
 
+test_expect_success '--dry-run without --delete-merged is rejected' '
+       test_must_fail git -C forked branch --dry-run 2>err &&
+       test_grep "requires --delete-merged" err
+'
+
 test_done