Testable install script

* wraps main code into a function
* EnvVar-based install start
* Clean environment after install

test/install_script/nvm_do_install

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+NVM_ENV=testing . ../../install.sh
+
+#nvm_do_install is available
+type nvm_do_install > /dev/null 2>&1

test/install_script/nvm_reset

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+NVM_ENV=testing . ../../install.sh
+
+safe_type() {
+  type "$1" > /dev/null 2>&1 && return 0 || return 1
+}
+
+# Check nvm_reset exists
+type nvm_reset > /dev/null 2>&1
+
+# Apply nvm_reset
+nvm_reset
+
+# The names should be unset
+! safe_type nvm_do_install && \
+  ! safe_type nvm_has && \
+  ! safe_type nvm_download && \
+  ! safe_type install_nvm_as_script && \
+  ! safe_type install_nvm_from_git && \
+  ! safe_type nvm_reset