Ensure that if `npm config get prefix` is set to something outside `nvm`, that `nvm use` refuses to work.

Fixes #606.

nvm.sh

@@ -1267,9 +1267,17 @@ nvm_die_on_prefix() {
     return 2
   fi
 
+  if [ -n "$PREFIX" ] && ! (nvm_tree_contains_path "$NVM_DIR" "$PREFIX" >/dev/null 2>&1); then
+    nvm deactivate >/dev/null 2>&1
+    echo >&2 "nvm is not compatible with the \"PREFIX\" environment variable: currently set to \"$PREFIX\""
+    echo >&2 "Run \`unset PREFIX\` to unset it."
+    return 3
+  fi
+
   if ! nvm_has 'npm'; then
     return
   fi
+
   local NVM_NPM_PREFIX
   NVM_NPM_PREFIX="$(npm config get prefix)"
   if ! (nvm_tree_contains_path "$NVM_DIR" "$NVM_NPM_PREFIX" >/dev/null 2>&1); then
@@ -1283,7 +1291,7 @@ nvm_die_on_prefix() {
       else
         echo >&2 "Run \`$NVM_COMMAND\` to unset it."
       fi
-      return 3
+      return 4
     fi
   fi
 }
@@ -1596,11 +1604,15 @@ nvm() {
       local PROVIDED_VERSION
       local NVM_USE_SILENT
       NVM_USE_SILENT=0
+      local NVM_DELETE_PREFIX
+      NVM_DELETE_PREFIX=0
+
       shift # remove "use"
       while [ $# -ne 0 ]
       do
         case "$1" in
           --silent) NVM_USE_SILENT=1 ;;
+          --delete-prefix) NVM_DELETE_PREFIX=1 ;;
           *)
             if [ -n "$1" ]; then
               PROVIDED_VERSION="$1"
@@ -1690,6 +1702,19 @@ nvm() {
           echo "Now using node $VERSION$(nvm_print_npm_version)"
         fi
       fi
+      if [ "_$VERSION" != "_system" ]; then
+        local NVM_USE_CMD
+        NVM_USE_CMD="nvm use --delete-prefix"
+        if [ -n "$PROVIDED_VERSION" ]; then
+          NVM_USE_CMD="$NVM_USE_CMD $VERSION"
+        fi
+        if [ $NVM_USE_SILENT -eq 1 ]; then
+          NVM_USE_CMD="$NVM_USE_CMD --silent"
+        fi
+        if ! nvm_die_on_prefix "$NVM_DELETE_PREFIX" "$NVM_USE_CMD"; then
+          return 11
+        fi
+      fi
     ;;
     "run" )
       local provided_version

test/fast/Running "nvm deactivate" should unset the nvm environment variables.

@@ -7,7 +7,7 @@ die () { echo $@ ; exit 1; }
 [ `expr $PATH : ".*v0.2.3/.*/bin"` = 0 ] || echo "WARNING: Unexpectedly found v0.2.3 already active" >&2
 
 . ../../nvm.sh
-nvm use v0.2.3 || die "Failed to activate v0.2.3"
+nvm use --delete-prefix v0.2.3 || die "Failed to activate v0.2.3"
 [ `expr "$PATH" : ".*v0.2.3/.*/bin"` != 0 ] || die "PATH not set up properly"
 [ `expr "$NODE_PATH" : ".*v0.2.3/.*/lib/node_modules"` = 0 ] || die "NODE_PATH should not contain (npm root -g)"
 # ^ note: NODE_PATH should not contain `npm root -g` since globals should not be requireable

test/fast/Unit tests/nvm_die_on_prefix

@@ -43,6 +43,13 @@ npm() {
 OUTPUT="$(nvm_die_on_prefix 0 foo 2>&1)"
 [ -z "$OUTPUT" ] || die "'nvm_die_on_prefix' was not a noop when prefix is good; got '$OUTPUT'"
 
+OUTPUT="$(PREFIX=bar nvm_die_on_prefix 0 foo 2>&1)"
+EXPECTED_OUTPUT='nvm is not compatible with the "PREFIX" environment variable: currently set to "bar"
+Run `unset PREFIX` to unset it.'
+EXIT_CODE="$(PREFIX=bar nvm_die_on_prefix 0 foo >/dev/null 2>&1; echo $?)"
+[ "_$OUTPUT" = "_$EXPECTED_OUTPUT" ] || die "'PREFIX=bar nvm_die_on_prefix 0 foo' did not error with '$EXPECTED_OUTPUT'; got '$OUTPUT'"
+[ "_$EXIT_CODE" = "_3" ] || die "'PREFIX=bar nvm_die_on_prefix 0 foo' did not exit with 3; got '$EXIT_CODE'"
+
 npm() {
   local args
   args="$@"
@@ -55,6 +62,6 @@ EXPECTED_OUTPUT="nvm is not compatible with the npm config \"prefix\" option: cu
 Run \`npm config delete prefix\` or \`foo\` to unset it."
 EXIT_CODE="$(nvm_die_on_prefix 0 foo >/dev/null 2>&1; echo $?)"
 [ "_$OUTPUT" = "_$EXPECTED_OUTPUT" ] || die "'nvm_die_on_prefix 0 foo' did not error with '$EXPECTED_OUTPUT' with bad prefix set; got '$OUTPUT'"
-[ "_$EXIT_CODE" = "_3" ] || die "'nvm_die_on_prefix 0 foo' did not exit with 3 with bad prefix set; got '$EXIT_CODE'"
+[ "_$EXIT_CODE" = "_4" ] || die "'nvm_die_on_prefix 0 foo' did not exit with 4 with bad prefix set; got '$EXIT_CODE'"
 
 cleanup

test/slow/nvm use/Running "nvm use" calls "nvm_die_on_prefix"

@@ -0,0 +1,22 @@
+#!/bin/sh
+
+die () { echo $@ ; exit 1; }
+
+. ../../../nvm.sh
+
+nvm deactivate >/dev/null 2>&1 || die 'deactivate failed'
+
+nvm_die_on_prefix() {
+  echo >&2 "| $1 | $2 |"
+  return 3
+}
+
+OUTPUT="$(nvm use --silent node)"
+EXPECTED_OUTPUT=""
+[ "_$OUTPUT" = "_$EXPECTED_OUTPUT" ] \
+  || die "'nvm use --silent node' did not call through to 'nvm_die_on_prefix' and give output '$EXPECTED_OUTPUT'; got '$OUTPUT'"
+
+EXIT_CODE="$(nvm use --silent node >/dev/null 2>&1; echo $?)"
+EXPECTED_CODE="11"
+[ "_$EXIT_CODE" = "_$EXPECTED_CODE" ] \
+  || die "'nvm use --silent node' when 'nvm_die_on_prefix' fails did not return '$EXPECTED_CODE'; got '$EXIT_CODE'"