[GSoC][RFC PATCH v5 3/6] builtin/for-each-ref: factor out core logic into a helper

From: Meet Soni <meetsoni3017@gmail.com>
Date: Aug 4, 2025, 09:22 UTC
Message-ID: <20250804092255.1092973-4-meetsoni3017@gmail.com>
In-Reply-To: <20250804092255.1092973-1-meetsoni3017@gmail.com>

The implementation of `git for-each-ref` is monolithic within `cmd_for_each_ref()`, making it impossible to share its logic with other commands. To enable code reuse for the upcoming `git refs list` subcommand, refactor the core logic into a shared helper function.

Introduce a new `for-each-ref.h` header to define the public interface for this shared logic. It contains the declaration for a new helper function, `for_each_ref_core()`, and a macro for the common usage options.

Move the option parsing, filtering, and formatting logic from `cmd_for_each_ref()` into a new helper function named `for_each_ref_core()`. This helper is made generic by accepting the command's usage string as a parameter.

The original `cmd_for_each_ref()` is simplified to a thin wrapper that is only responsible for defining its specific usage array and calling the shared helper.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: shejialuo <shejialuo@gmail.com>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Meet Soni <meetsoni3017@gmail.com>
---
 builtin/for-each-ref.c | 41 +++++++++++++++++++----------------------
 for-each-ref.h         | 26 ++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 22 deletions(-)
 create mode 100644 for-each-ref.h

diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
index b2186f9f9a..2d4945379a 100644
--- a/builtin/for-each-ref.c
+++ b/builtin/for-each-ref.c
@@ -1,6 +1,7 @@
 #include "builtin.h"
 #include "commit.h"
 #include "config.h"
+#include "for-each-ref.h"
 #include "gettext.h"
 #include "object.h"
 #include "parse-options.h"
@@ -8,24 +9,7 @@
 #include "strbuf.h"
 #include "strvec.h"
 
-#define COMMON_USAGE_FOR_EACH_REF \
-	"[--count=<count>] [--shell|--perl|--python|--tcl]\n" \
-	"                         [(--sort=<key>)...] [--format=<format>]\n" \
-	"                         [--include-root-refs] [ --stdin | <pattern>... ]\n" \
-	"                         [--points-at=<object>]\n" \
-	"                         [--merged[=<object>]] [--no-merged[=<object>]]\n" \
-	"                         [--contains[=<object>]] [--no-contains[=<object>]]\n" \
-	"                         [--exclude=<pattern> ...]"
-
-static char const * const for_each_ref_usage[] = {
-	"git for-each-ref " COMMON_USAGE_FOR_EACH_REF,
-	NULL
-};
-
-int cmd_for_each_ref(int argc,
-		     const char **argv,
-		     const char *prefix,
-		     struct repository *repo)
+int for_each_ref_core(int argc, const char **argv, const char *prefix, struct repository *repo, const char *const *usage)
 {
 	struct ref_sorting *sorting;
 	struct string_list sorting_options = STRING_LIST_INIT_DUP;
@@ -73,17 +57,17 @@ int cmd_for_each_ref(int argc,
 	/* Set default (refname) sorting */
 	string_list_append(&sorting_options, "refname");
 
-	parse_options(argc, argv, prefix, opts, for_each_ref_usage, 0);
+	parse_options(argc, argv, prefix, opts, usage, 0);
 	if (format.array_opts.max_count < 0) {
 		error("invalid --count argument: `%d'", format.array_opts.max_count);
-		usage_with_options(for_each_ref_usage, opts);
+		usage_with_options(usage, opts);
 	}
 	if (HAS_MULTI_BITS(format.quote_style)) {
 		error("more than one quoting style?");
-		usage_with_options(for_each_ref_usage, opts);
+		usage_with_options(usage, opts);
 	}
 	if (verify_ref_format(&format))
-		usage_with_options(for_each_ref_usage, opts);
+		usage_with_options(usage, opts);
 
 	sorting = ref_sorting_options(&sorting_options);
 	ref_sorting_set_sort_flags_all(sorting, REF_SORTING_ICASE, icase);
@@ -117,3 +101,16 @@ int cmd_for_each_ref(int argc,
 	strvec_clear(&vec);
 	return 0;
 }
+
+int cmd_for_each_ref(int argc,
+		     const char **argv,
+		     const char *prefix,
+		     struct repository *repo)
+{
+	static char const * const for_each_ref_usage[] = {
+		N_("git for-each-ref " COMMON_USAGE_FOR_EACH_REF),
+		NULL
+	};
+
+	return for_each_ref_core(argc, argv, prefix, repo, for_each_ref_usage);
+}
diff --git a/for-each-ref.h b/for-each-ref.h
new file mode 100644
index 0000000000..1662d25417
--- /dev/null
+++ b/for-each-ref.h
@@ -0,0 +1,26 @@
+#ifndef FOR_EACH_REF_H
+#define FOR_EACH_REF_H
+
+struct repository;
+
+/*
+ * Shared usage string for options common to git-for-each-ref(1)
+ * and git-refs-list(1). The command-specific part (e.g., "git refs list ")
+ * must be prepended by the caller.
+ */
+#define COMMON_USAGE_FOR_EACH_REF \
+	"[--count=<count>] [--shell|--perl|--python|--tcl]\n" \
+	"                         [(--sort=<key>)...] [--format=<format>]\n" \
+	"                         [--include-root-refs] [ --stdin | <pattern>... ]\n" \
+	"                         [--points-at=<object>]\n" \
+	"                         [--merged[=<object>]] [--no-merged[=<object>]]\n" \
+	"                         [--contains[=<object>]] [--no-contains[=<object>]]\n" \
+	"                         [--exclude=<pattern> ...]"
+
+/*
+ * The core logic for for-each-ref and its clones.
+ */
+int for_each_ref_core(int argc, const char **argv, const char *prefix,
+		      struct repository *repo, const char *const *usage);
+
+#endif /* FOR_EACH_REF_H */

-- 
2.34.1