t6300: avoid hard-coding object sizes

f4ee22b (ref-filter: add tests for objectsize:disk, 2018-12-24)
hard-coded the expected object sizes.  Coincidentally the size of commit
and tag is the same with zlib at the default compression level.

1f5f8f3 (t6300: abstract away SHA-1-specific constants, 2020-02-22)
encoded the sizes as a single value, which coincidentally also works
with sha256.

Different compression libraries like zlib-ng may arrive at different
values.  Get them from the file system instead of hard-coding them to
make switching the compression library (or changing the compression
level) easier.

Reported-by: Ondrej Pohorelsky <[email protected]>
Signed-off-by: René Scharfe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

t/t6300-for-each-ref.sh

@@ -20,12 +20,13 @@ setdate_and_increment () {
     export GIT_COMMITTER_DATE GIT_AUTHOR_DATE
 }
 
-test_expect_success setup '
-	test_oid_cache <<-EOF &&
-	disklen sha1:138
-	disklen sha256:154
-	EOF
+test_object_file_size () {
+	oid=$(git rev-parse "$1")
+	path=".git/objects/$(test_oid_to_path $oid)"
+	test_file_size "$path"
+}
 
+test_expect_success setup '
 	# setup .mailmap
 	cat >.mailmap <<-EOF &&
 	A Thor <[email protected]> A U Thor <[email protected]>
@@ -94,7 +95,6 @@ test_atom () {
 }
 
 hexlen=$(test_oid hexsz)
-disklen=$(test_oid disklen)
 
 test_atom head refname refs/heads/main
 test_atom head refname: refs/heads/main
@@ -129,7 +129,7 @@ test_atom head push:strip=1 remotes/myfork/main
 test_atom head push:strip=-1 main
 test_atom head objecttype commit
 test_atom head objectsize $((131 + hexlen))
-test_atom head objectsize:disk $disklen
+test_atom head objectsize:disk $(test_object_file_size refs/heads/main)
 test_atom head deltabase $ZERO_OID
 test_atom head objectname $(git rev-parse refs/heads/main)
 test_atom head objectname:short $(git rev-parse --short refs/heads/main)
@@ -203,8 +203,8 @@ test_atom tag upstream ''
 test_atom tag push ''
 test_atom tag objecttype tag
 test_atom tag objectsize $((114 + hexlen))
-test_atom tag objectsize:disk $disklen
-test_atom tag '*objectsize:disk' $disklen
+test_atom tag objectsize:disk $(test_object_file_size refs/tags/testtag)
+test_atom tag '*objectsize:disk' $(test_object_file_size refs/heads/main)
 test_atom tag deltabase $ZERO_OID
 test_atom tag '*deltabase' $ZERO_OID
 test_atom tag objectname $(git rev-parse refs/tags/testtag)