Subject: Re: [PATCH 1/9] t/: new helper for tests that pass with ort but fail with recursive

From: Đoàn Trần Công Danh <[email-masked]>
Date: Sat, 24 Oct 2020 17:49:10 +0700

On 2020-10-23 16:01:16+0000, Elijah Newren via GitGitGadget <[email-masked]> wrote:
> +test_expect_merge_algorithm () {
> +	status_for_recursive=$1
> +	shift
> +	status_for_ort=$1
> +	shift
> +
> +	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
> +	then
> +		test_expect_${status_for_ort} "$@"
> +	else
> +		test_expect_${status_for_recursive} "$@"
> -test_expect_failure 'check symlink modify/modify' '
> +test_expect_merge_algorithm failure success 'check symlink modify/modify' '

I find this series of "failure success" hard to decode without
understanding what it would be, then I need to keep rememberring which
status is corresponding with with algorithm.

Perhaps this patch is a bit easier to read. This is largely based on
your patch. (I haven't read other patches, yet).

What do you think?

-------------8<------------
From: =?UTF-8?q?=C4=90o=C3=A0n=20Tr=E1=BA=A7n=20C=C3=B4ng=20Danh?=
 <[email-masked]>
Date: Sat, 24 Oct 2020 17:41:02 +0700
Subject: [PATCH] t/: new helper for testing merge that allow failure for some
 algorithm

There are a number of tests that the "recursive" backend does not handle
correctly but which the redesign in "ort" will.

Add a new helper in lib-merge.sh for selecting a different test expectation
based on the setting of GIT_TEST_MERGE_ALGORITHM, and use it in various
testcases to document that we expect them to be success by default
but failure with certain algorithm.

Signed-off-by: Đoàn Trần Công Danh <[email-masked]>
---
 t/lib-merge.sh                         | 19 +++++++++++++++++++
 t/t6416-recursive-corner-cases.sh      | 11 ++++++-----
 t/t6422-merge-rename-corner-cases.sh   |  7 ++++---
 t/t6423-merge-rename-directories.sh    | 13 +++++++------
 t/t6426-merge-skip-unneeded-updates.sh |  3 ++-
 t/t6430-merge-recursive.sh             |  3 ++-
 6 files changed, 40 insertions(+), 16 deletions(-)
 create mode 100644 t/lib-merge.sh

diff --git a/t/lib-merge.sh b/t/lib-merge.sh
new file mode 100644
index 0000000000..efd8b9615c
--- /dev/null
+++ b/t/lib-merge.sh
@@ -0,0 +1,19 @@
+# Helper functions used by merge tests.
+
+test_expect_merge_success() {
+	exception="$1"
+	: "${GIT_TEST_MERGE_ALGORITHM:=recursive}"
+	case ",$exception," in
+	*,$GIT_TEST_MERGE_ALGORITHM=failure,*)
+		shift
+		test_expect_failure "$@" ;;
+	*,$GIT_TEST_MERGE_ALGORITHM=*)
+		BUG "exception must be failure only" ;;
+	*=failure,)
+		shift
+		test_expect_success "$@" ;;
+	*)
+		# No exception
+		test_expect_success "$@" ;;
+	esac
+}
diff --git a/t/t6416-recursive-corner-cases.sh b/t/t6416-recursive-corner-cases.sh
index fd98989b14..d13c1afb4a 100755
--- a/t/t6416-recursive-corner-cases.sh
+++ b/t/t6416-recursive-corner-cases.sh
@@ -3,6 +3,7 @@
 test_description='recursive merge corner cases involving criss-cross merges'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-merge.sh
 
 #
 #  L1  L2
@@ -1069,7 +1070,7 @@ test_expect_success 'setup symlink modify/modify' '
 	)
 '
 
-test_expect_failure 'check symlink modify/modify' '
+test_expect_merge_success recursive=failure 'check symlink modify/modify' '
 	(
 		cd symlink-modify-modify &&
 
@@ -1135,7 +1136,7 @@ test_expect_success 'setup symlink add/add' '
 	)
 '
 
-test_expect_failure 'check symlink add/add' '
+test_expect_merge_success recursive=failure 'check symlink add/add' '
 	(
 		cd symlink-add-add &&
 
@@ -1223,7 +1224,7 @@ test_expect_success 'setup submodule modify/modify' '
 	)
 '
 
-test_expect_failure 'check submodule modify/modify' '
+test_expect_merge_success recursive=failure 'check submodule modify/modify' '
 	(
 		cd submodule-modify-modify &&
 
@@ -1311,7 +1312,7 @@ test_expect_success 'setup submodule add/add' '
 	)
 '
 
-test_expect_failure 'check submodule add/add' '
+test_expect_merge_success recursive=failure 'check submodule add/add' '
 	(
 		cd submodule-add-add &&
 
@@ -1386,7 +1387,7 @@ test_expect_success 'setup conflicting entry types (submodule vs symlink)' '
 	)
 '
 
-test_expect_failure 'check conflicting entry types (submodule vs symlink)' '
+test_expect_merge_success recursive=failure 'check conflicting entry types (submodule vs symlink)' '
 	(
 		cd submodule-symlink-add-add &&
 
diff --git a/t/t6422-merge-rename-corner-cases.sh b/t/t6422-merge-rename-corner-cases.sh
index 3375eaf4e7..0c8eb4df8a 100755
--- a/t/t6422-merge-rename-corner-cases.sh
+++ b/t/t6422-merge-rename-corner-cases.sh
@@ -4,6 +4,7 @@ test_description="recursive merge corner cases w/ renames but not criss-crosses"
 # t6036 has corner cases that involve both criss-cross merges and renames
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-merge.sh
 
 test_setup_rename_delete_untracked () {
 	test_create_repo rename-delete-untracked &&
@@ -878,7 +879,7 @@ test_setup_rad () {
 	)
 }
 
-test_expect_failure 'rad-check: rename/add/delete conflict' '
+test_expect_merge_success recursive=failure 'rad-check: rename/add/delete conflict' '
 	test_setup_rad &&
 	(
 		cd rad &&
@@ -951,7 +952,7 @@ test_setup_rrdd () {
 	)
 }
 
-test_expect_failure 'rrdd-check: rename/rename(2to1)/delete/delete conflict' '
+test_expect_merge_success recursive=failure 'rrdd-check: rename/rename(2to1)/delete/delete conflict' '
 	test_setup_rrdd &&
 	(
 		cd rrdd &&
@@ -1040,7 +1041,7 @@ test_setup_mod6 () {
 	)
 }
 
-test_expect_failure 'mod6-check: chains of rename/rename(1to2) and rename/rename(2to1)' '
+test_expect_merge_success recursive=failure 'mod6-check: chains of rename/rename(1to2) and rename/rename(2to1)' '
 	test_setup_mod6 &&
 	(
 		cd mod6 &&
diff --git a/t/t6423-merge-rename-directories.sh b/t/t6423-merge-rename-directories.sh
index 06b46af765..249fbb6853 100755
--- a/t/t6423-merge-rename-directories.sh
+++ b/t/t6423-merge-rename-directories.sh
@@ -26,6 +26,7 @@ test_description="recursive merge with directory renames"
 #                     files that might be renamed into each other's paths.)
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-merge.sh

 ###########################################################################
@@ -1339,7 +1340,7 @@ test_setup_6b1 () {
 	)
 }
 
-test_expect_failure '6b1: Same renames done on both sides, plus another rename' '
+test_expect_merge_success recursive=failure '6b1: Same renames done on both sides, plus another rename' '
 	test_setup_6b1 &&
 	(
 		cd 6b1 &&
@@ -1412,7 +1413,7 @@ test_setup_6b2 () {
 	)
 }
 
-test_expect_failure '6b2: Same rename done on both sides' '
+test_expect_merge_success recursive=failure '6b2: Same rename done on both sides' '
 	test_setup_6b2 &&
 	(
 		cd 6b2 &&
@@ -3471,7 +3472,7 @@ test_setup_10e () {
 	)
 }
 
-test_expect_failure '10e: Does git complain about untracked file that is not really in the way?' '
+test_expect_merge_success recursive=failure '10e: Does git complain about untracked file that is not really in the way?' '
 	test_setup_10e &&
 	(
 		cd 10e &&
@@ -4104,7 +4105,7 @@ test_setup_12b1 () {
 	)
 }
 
-test_expect_failure '12b1: Moving two directory hierarchies into each other' '
+test_expect_merge_success recursive=failure '12b1: Moving two directory hierarchies into each other' '
 	test_setup_12b1 &&
 	(
 		cd 12b1 &&
@@ -4272,7 +4273,7 @@ test_setup_12c1 () {
 	)
 }
 
-test_expect_failure '12c1: Moving one directory hierarchy into another w/ content merge' '
+test_expect_merge_success recursive=failure '12c1: Moving one directory hierarchy into another w/ content merge' '
 	test_setup_12c1 &&
 	(
 		cd 12c1 &&
@@ -4632,7 +4633,7 @@ test_setup_12f () {
 	)
 }
 
-test_expect_failure '12f: Trivial directory resolve, caching, all kinds of fun' '
+test_expect_merge_success recursive=failure '12f: Trivial directory resolve, caching, all kinds of fun' '
 	test_setup_12f &&
 	(
 		cd 12f &&
diff --git a/t/t6426-merge-skip-unneeded-updates.sh b/t/t6426-merge-skip-unneeded-updates.sh
index 699813671c..8510d4da8b 100755
--- a/t/t6426-merge-skip-unneeded-updates.sh
+++ b/t/t6426-merge-skip-unneeded-updates.sh
@@ -23,6 +23,7 @@ test_description="merge cases"
 #                     files that might be renamed into each other's paths.)
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-merge.sh

 ###########################################################################
@@ -666,7 +667,7 @@ test_setup_4a () {
 #   correct requires doing the merge in-memory first, then realizing that no
 #   updates to the file are necessary, and thus that we can just leave the path
 #   alone.
-test_expect_failure '4a: Change on A, change on B subset of A, dirty mods present' '
+test_expect_merge_success recursive=failure '4a: Change on A, change on B subset of A, dirty mods present' '
 	test_setup_4a &&
 	(
 		cd 4a &&
diff --git a/t/t6430-merge-recursive.sh b/t/t6430-merge-recursive.sh
index a328260d42..4795a7abd0 100755
--- a/t/t6430-merge-recursive.sh
+++ b/t/t6430-merge-recursive.sh
@@ -3,6 +3,7 @@
 test_description='merge-recursive backend test'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-merge.sh
 
 test_expect_success 'setup 1' '
 
@@ -641,7 +642,7 @@ test_expect_success 'merge-recursive copy vs. rename' '
 	test_cmp expected actual
 '
 
-test_expect_failure 'merge-recursive rename vs. rename/symlink' '
+test_expect_merge_success recursive=failure 'merge-recursive rename vs. rename/symlink' '
 
 	git checkout -f rename &&
 	git merge rename-ln &&
-- 
2.29.0.rc1