Unit tests: add `nvm_has`

test/fast/Unit tests/nvm_has

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+die () { echo $@ ; exit 1; }
+
+. ../../../nvm.sh
+
+nvm_has cat && type cat > /dev/null || die 'nvm_has locates "cat" properly'
+
+[ "~$(nvm_has foobarbaz 2>&1)" = "~" ] || die "nvm_has does not suppress error output"
+
+! nvm_has foobarbaz && ! type foobarbaz >/dev/null 2>&1 || die "nvm_has does not return a nonzero exit code when not found"
+