t6601: add helper for testing path-walk API

Add some tests based on the current behavior, doing interesting checks
for different sets of branches, ranges, and the --boundary option. This
sets a baseline for the behavior and we can extend it as new options are
introduced.

Store and output a 'batch_nr' value so we can demonstrate that the paths are
grouped together in a batch and not following some other ordering. This
allows us to test the depth-first behavior of the path-walk API. However, we
purposefully do not test the order of the objects in the batch, so the
output is compared to the expected output through a sort.

It is important to mention that the behavior of the API will change soon as
we start to handle UNINTERESTING objects differently, but these tests will
demonstrate the change in behavior.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/t/helper/test-path-walk.c b/t/helper/test-path-walk.c
new file mode 100644
index 0000000000..def7c81ac4
--- /dev/null
+++ b/t/helper/test-path-walk.c
@@ -0,0 +1,84 @@
+#define USE_THE_REPOSITORY_VARIABLE
+
+#include "test-tool.h"
+#include "environment.h"
+#include "hex.h"
+#include "object-name.h"
+#include "object.h"
+#include "pretty.h"
+#include "revision.h"
+#include "setup.h"
+#include "parse-options.h"
+#include "path-walk.h"
+#include "oid-array.h"
+
+static const char * const path_walk_usage[] = {
+	N_("test-tool path-walk <options> -- <revision-options>"),
+	NULL
+};
+
+struct path_walk_test_data {
+	uintmax_t batch_nr;
+	uintmax_t tree_nr;
+	uintmax_t blob_nr;
+};
+
+static int emit_block(const char *path, struct oid_array *oids,
+		      enum object_type type, void *data)
+{
+	struct path_walk_test_data *tdata = data;
+	const char *typestr;
+
+	if (type == OBJ_TREE)
+		tdata->tree_nr += oids->nr;
+	else if (type == OBJ_BLOB)
+		tdata->blob_nr += oids->nr;
+	else
+		BUG("we do not understand this type");
+
+	typestr = type_name(type);
+
+	for (size_t i = 0; i < oids->nr; i++)
+		printf("%"PRIuMAX":%s:%s:%s\n",
+		       tdata->batch_nr, typestr, path,
+		       oid_to_hex(&oids->oid[i]));
+
+	tdata->batch_nr++;
+	return 0;
+}
+
+int cmd__path_walk(int argc, const char **argv)
+{
+	int res;
+	struct rev_info revs = REV_INFO_INIT;
+	struct path_walk_info info = PATH_WALK_INFO_INIT;
+	struct path_walk_test_data data = { 0 };
+	struct option options[] = {
+		OPT_END(),
+	};
+
+	setup_git_directory();
+	revs.repo = the_repository;
+
+	argc = parse_options(argc, argv, NULL,
+			     options, path_walk_usage,
+			     PARSE_OPT_KEEP_UNKNOWN_OPT | PARSE_OPT_KEEP_ARGV0);
+
+	if (argc > 1)
+		setup_revisions(argc, argv, &revs, NULL);
+	else
+		usage(path_walk_usage[0]);
+
+	info.revs = &revs;
+	info.path_fn = emit_block;
+	info.path_fn_data = &data;
+
+	res = walk_objects_by_path(&info);
+
+	printf("trees:%" PRIuMAX "\n"
+	       "blobs:%" PRIuMAX "\n",
+	       data.tree_nr, data.blob_nr);
+
+	release_revisions(&revs);
+	return res;
+}