Refactor test code of python-build. Use curl during tests by default

plugins/python-build/test/build.bats

@@ -6,7 +6,6 @@ export MAKE=make
 export MAKE_OPTS="-j 2"
 export CC=cc
 export -n PYTHON_CONFIGURE_OPTS
-export PYTHON_BUILD_HTTP_CLIENT="curl"
 
 setup() {
   mkdir -p "$INSTALL_ROOT"

plugins/python-build/test/cache.bats

@@ -3,8 +3,6 @@
 load test_helper
 export PYTHON_BUILD_SKIP_MIRROR=1
 export PYTHON_BUILD_CACHE_PATH="$TMP/cache"
-export PYTHON_BUILD_CURL_OPTS=
-export PYTHON_BUILD_HTTP_CLIENT="curl"
 
 setup() {
   mkdir "$PYTHON_BUILD_CACHE_PATH"

plugins/python-build/test/checksum.bats

@@ -3,8 +3,6 @@
 load test_helper
 export PYTHON_BUILD_SKIP_MIRROR=1
 export PYTHON_BUILD_CACHE_PATH=
-export PYTHON_BUILD_CURL_OPTS=
-export PYTHON_BUILD_HTTP_CLIENT="curl"
 
 
 @test "package URL without checksum" {

plugins/python-build/test/fetch.bats

@@ -3,8 +3,6 @@
 load test_helper
 export PYTHON_BUILD_SKIP_MIRROR=1
 export PYTHON_BUILD_CACHE_PATH=
-export PYTHON_BUILD_ARIA2_OPTS=
-export PYTHON_BUILD_HTTP_CLIENT="curl"
 
 setup() {
   export PYTHON_BUILD_BUILD_PATH="${TMP}/source"
@@ -21,6 +19,7 @@ setup() {
 }
 
 @test "using aria2c if available" {
+  export PYTHON_BUILD_ARIA2_OPTS=
   export PYTHON_BUILD_HTTP_CLIENT="aria2c"
   stub aria2c "--allow-overwrite=true --no-conf=true -o * http://example.com/* : cp $FIXTURE_ROOT/\${5##*/} \$4"
 

plugins/python-build/test/mirror.bats

@@ -4,8 +4,6 @@ load test_helper
 export PYTHON_BUILD_SKIP_MIRROR=
 export PYTHON_BUILD_CACHE_PATH=
 export PYTHON_BUILD_MIRROR_URL=http://mirror.example.com
-export PYTHON_BUILD_CURL_OPTS=
-export PYTHON_BUILD_HTTP_CLIENT="curl"
 
 
 @test "package URL without checksum bypasses mirror" {

plugins/python-build/test/test_helper.bash

@@ -1,4 +1,6 @@
 export TMP="$BATS_TEST_DIRNAME/tmp"
+export RUBY_BUILD_CURL_OPTS=
+export RUBY_BUILD_HTTP_CLIENT="curl"
 
 if [ "$FIXTURE_ROOT" != "$BATS_TEST_DIRNAME/fixtures" ]; then
   export FIXTURE_ROOT="$BATS_TEST_DIRNAME/fixtures"

test/test_helper.bash

@@ -1,6 +1,5 @@
 unset PYENV_VERSION
 unset PYENV_DIR
-unset PYTHON_BUILD_HTTP_CLIENT
 
 # guard against executing this block twice due to bats internals
 if [ -z "$PYENV_TEST_DIR" ]; then