t7800: replace "wc -l" with test_line_count

Make t7800 easier to debug by capturing output into temporary files and
using test_line_count to make assertions on those files.

Signed-off-by: David Aguilar <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: davvid

t/t7800-difftool.sh

@@ -290,8 +290,8 @@ test_expect_success 'difftool + mergetool config variables' '
 test_expect_success 'difftool.<tool>.path' '
 	test_config difftool.tkdiff.path echo &&
 	git difftool --tool=tkdiff --no-prompt branch >output &&
-	lines=$(grep file output | wc -l) &&
-	test "$lines" -eq 1
+	grep file output >grep-output &&
+	test_line_count = 1 grep-output
 '
 
 test_expect_success 'difftool --extcmd=cat' '
@@ -428,9 +428,12 @@ run_dir_diff_test 'difftool --dir-diff branch from subdirectory' '
 		git difftool --dir-diff $symlinks --extcmd ls branch >output &&
 		# "sub" must only exist in "right"
 		# "file" and "file2" must be listed in both "left" and "right"
-		test "1" = $(grep sub output | wc -l) &&
-		test "2" = $(grep file"$" output | wc -l) &&
-		test "2" = $(grep file2 output | wc -l)
+		grep sub output > sub-output &&
+		test_line_count = 1 sub-output &&
+		grep file"$" output >file-output &&
+		test_line_count = 2 file-output &&
+		grep file2 output >file2-output &&
+		test_line_count = 2 file2-output
 	)
 '
 
@@ -440,9 +443,11 @@ run_dir_diff_test 'difftool --dir-diff v1 from subdirectory' '
 		git difftool --dir-diff $symlinks --extcmd ls v1 >output &&
 		# "sub" and "file" exist in both v1 and HEAD.
 		# "file2" is unchanged.
-		test "2" = $(grep sub output | wc -l) &&
-		test "2" = $(grep file output | wc -l) &&
-		test "0" = $(grep file2 output | wc -l)
+		grep sub output >sub-output &&
+		test_line_count = 2 sub-output &&
+		grep file output >file-output &&
+		test_line_count = 2 file-output &&
+		! grep file2 output
 	)
 '
 
@@ -452,8 +457,9 @@ run_dir_diff_test 'difftool --dir-diff branch from subdirectory w/ pathspec' '
 		git difftool --dir-diff $symlinks --extcmd ls branch -- .>output &&
 		# "sub" only exists in "right"
 		# "file" and "file2" must not be listed
-		test "1" = $(grep sub output | wc -l) &&
-		test "0" = $(grep file output | wc -l)
+		grep sub output >sub-output &&
+		test_line_count = 1 sub-output &&
+		! grep file output
 	)
 '
 
@@ -463,8 +469,9 @@ run_dir_diff_test 'difftool --dir-diff v1 from subdirectory w/ pathspec' '
 		git difftool --dir-diff $symlinks --extcmd ls v1 -- .>output &&
 		# "sub" exists in v1 and HEAD
 		# "file" is filtered out by the pathspec
-		test "2" = $(grep sub output | wc -l) &&
-		test "0" = $(grep file output | wc -l)
+		grep sub output >sub-output &&
+		test_line_count = 2 sub-output &&
+		! grep file output
 	)
 '