tests: replace test_tristate with "git env--helper"

The test_tristate helper introduced in 83d842dc8c ("tests: turn on
network daemon tests by default", 2014-02-10) can now be better
implemented with "git env--helper" to give the variables in question
the standard boolean behavior.

The reason for the "tristate" was to have all of false/true/auto,
where "auto" meant either "false" or "true" depending on what the
fallback was. With the --default option to "git env--helper" we can
simply have e.g. GIT_TEST_HTTPD where we know if it's true because the
user asked explicitly ("true"), or true implicitly ("auto").

This breaks backwards compatibility for explicitly setting "auto" for
these variables, but I don't think anyone cares. That was always
intended to be internal.

This means the test_normalize_bool() code in test-lib-functions.sh
goes away in addition to test_tristate(). We still need the
test_skip_or_die() helper, but now it takes the variable name instead
of the value, and uses "git env--bool" to distinguish a default "true"
from an explicit "true" (in those "explicit true" cases we want to
fail the test in question).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 49 deletions

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 0367cec..527508c 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -1035,62 +1035,20 @@ perl () {
 	command "$PERL_PATH" "$@" 2>&7
 } 7>&2 2>&4
 
-# Is the value one of the various ways to spell a boolean true/false?
-test_normalize_bool () {
-	git -c magic.variable="$1" config --bool magic.variable 2>/dev/null
-}
-
-# Given a variable $1, normalize the value of it to one of "true",
-# "false", or "auto" and store the result to it.
-#
-#     test_tristate GIT_TEST_HTTPD
-#
-# A variable set to an empty string is set to 'false'.
-# A variable set to 'false' or 'auto' keeps its value.
-# Anything else is set to 'true'.
-# An unset variable defaults to 'auto'.
-#
-# The last rule is to allow people to set the variable to an empty
-# string and export it to decline testing the particular feature
-# for versions both before and after this change.  We used to treat
-# both unset and empty variable as a signal for "do not test" and
-# took any non-empty string as "please test".
-
-test_tristate () {
-	if eval "test x\"\${$1+isset}\" = xisset"
-	then
-		# explicitly set
-		eval "
-			case \"\$$1\" in
-			'')	$1=false ;;
-			auto)	;;
-			*)	$1=\$(test_normalize_bool \$$1 || echo true) ;;
-			esac
-		"
-	else
-		eval "$1=auto"
-	fi
-}
-
 # Exit the test suite, either by skipping all remaining tests or by
-# exiting with an error. If "$1" is "auto", we then we assume we were
-# opportunistically trying to set up some tests and we skip. If it is
-# "true", then we report a failure.
+# exiting with an error. If our prerequisite variable $1 falls back
+# on a default assume we were opportunistically trying to set up some
+# tests and we skip. If it is explicitly "true", then we report a failure.
 #
 # The error/skip message should be given by $2.
 #
 test_skip_or_die () {
-	case "$1" in
-	auto)
+	if ! git env--helper --mode-bool --variable=$1 --default=0 --exit-code --quiet
+	then
 		skip_all=$2
 		test_done
-		;;
-	true)
-		error "$2"
-		;;
-	*)
-		error "BUG: test tristate is '$1' (real error: $2)"
-	esac
+	fi
+	error "$2"
 }
 
 # The following mingw_* functions obey POSIX shell syntax, but are actually