Add bats test for python-build

plugins/python-build/test/installer.bats

@@ -0,0 +1,49 @@
+#!/usr/bin/env bats
+
+load test_helper
+
+@test "installs python-build into PREFIX" {
+  cd "$TMP"
+  PREFIX="${PWD}/usr" run "${BATS_TEST_DIRNAME}/../install.sh"
+  assert_success ""
+
+  cd usr
+
+  assert [ -x bin/python-build ]
+  assert [ -x bin/pyenv-install ]
+  assert [ -x bin/pyenv-uninstall ]
+
+  assert [ -e share/python-build/2.7.2 ]
+  assert [ -e share/python-build/pypy-2.0 ]
+}
+
+@test "overwrites old installation" {
+  cd "$TMP"
+  mkdir -p bin share/python-build
+  touch bin/python-build
+  touch share/python-build/2.7.2
+
+  PREFIX="$PWD" run "${BATS_TEST_DIRNAME}/../install.sh"
+  assert_success ""
+
+  assert [ -x bin/python-build ]
+  run grep "install_package" share/python-build/2.7.2
+  assert_success
+}
+
+@test "unrelated files are untouched" {
+  cd "$TMP"
+  mkdir -p bin share/bananas
+  chmod g-w bin
+  touch bin/bananas
+  touch share/bananas/docs
+
+  PREFIX="$PWD" run "${BATS_TEST_DIRNAME}/../install.sh"
+  assert_success ""
+
+  assert [ -e bin/bananas ]
+  assert [ -e share/bananas/docs ]
+
+  run ls -ld bin
+  assert_equal "r-x" "${output:4:3}"
+}