Don't mess with the order of the path locations when changing versions

nvm.sh

@@ -484,11 +484,24 @@ nvm_strip_path() {
     -e "s#${NVM_DIR}/versions/[^/]*/[^/]*${2-}[^:]*##g"
 }
 
-nvm_prepend_path() {
+nvm_change_path() {
+  # if there’s no initial path, just return the supplementary path
   if [ -z "${1-}" ]; then
-    nvm_echo "${2-}"
+    nvm_echo "${3-}${2-}"
+  # if the initial path doesn’t contain an nvm path, prepend the supplementary
+  # path
+  elif [ "${1#*$NVM_DIR}" == "$1" ]; then
+    nvm_echo "${3-}${2-}:${1-}"
+  # use sed to replace the existing nvm path with the supplementary path. This
+  # preserves the order of the path.
   else
-    nvm_echo "${2-}:${1-}"
+    nvm_echo "${1-}" | command sed \
+      -e "s#${NVM_DIR}/[^/]*${2-}[^:]*:#${3-}${2-}:#g" \
+      -e "s#:${NVM_DIR}/[^/]*${2-}[^:]*#:${3-}${2-}#g" \
+      -e "s#${NVM_DIR}/[^/]*${2-}[^:]*#${3-}${2-}#g" \
+      -e "s#${NVM_DIR}/versions/[^/]*/[^/]*${2-}[^:]*:#${3-}${2-}:#g" \
+      -e "s#:${NVM_DIR}/versions/[^/]*/[^/]*${2-}[^:]*#:${3-}${2-}#g" \
+      -e "s#${NVM_DIR}/versions/[^/]*/[^/]*${2-}[^:]*#${3-}${2-}#g"
   fi
 }
 
@@ -2636,18 +2649,14 @@ nvm() {
       local NVM_VERSION_DIR
       NVM_VERSION_DIR="$(nvm_version_path "$VERSION")"
 
-      # Strip other version from PATH
+      # Change current version
-      PATH="$(nvm_strip_path "$PATH" "/bin")"
+      PATH="$(nvm_change_path "$PATH" "/bin" "$NVM_VERSION_DIR")"
-      # Prepend current version
-      PATH="$(nvm_prepend_path "$PATH" "$NVM_VERSION_DIR/bin")"
       if nvm_has manpath; then
         if [ -z "$MANPATH" ]; then
           MANPATH=$(manpath)
         fi
-        # Strip other version from MANPATH
+        # Change current version
-        MANPATH="$(nvm_strip_path "$MANPATH" "/share/man")"
+        MANPATH="$(nvm_change_path "$MANPATH" "/share/man" "$NVM_VERSION_DIR")"
-        # Prepend current version
-        MANPATH="$(nvm_prepend_path "$MANPATH" "$NVM_VERSION_DIR/share/man")"
         export MANPATH
       fi
       export PATH
@@ -3146,7 +3155,7 @@ nvm() {
         nvm_ensure_default_set nvm_get_arch nvm_get_os \
         nvm_print_implicit_alias nvm_validate_implicit_alias \
         nvm_resolve_alias nvm_ls_current nvm_alias \
-        nvm_binary_available nvm_prepend_path nvm_strip_path \
+        nvm_binary_available nvm_change_path nvm_strip_path \
         nvm_num_version_groups nvm_format_version nvm_ensure_version_prefix \
         nvm_normalize_version nvm_is_valid_version \
         nvm_ensure_version_installed \

test/fast/Unit tests/nvm_change_path

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+die () { echo "$@" ; exit 1; }
+
+\. ../../../nvm.sh
+
+TEST_PATH=/usr/bin:/usr/local/bin
+
+NEW_PATH=`nvm_change_path "$TEST_PATH" "/bin" "$NVM_DIR/versions/node/v7.1.0/bin"`
+
+[ "$NEW_PATH" = "$NVM_DIR/versions/node/v7.1.0:/bin:/usr/bin:/usr/local/bin" ] || die "Not correctly changed: $NEW_PATH "
+
+
+TEST_PATH=/home/user/code/test/node_modules/.bin:$NVM_DIR/versions/node/v4.5.0:/usr/bin:/usr/local/bin
+
+NEW_PATH=`nvm_change_path "$TEST_PATH" "/bin" "$NVM_DIR/versions/node/v7.1.0/bin"`
+
+[ "$NEW_PATH" = "/home/user/code/test/node_modules/.bin:$NVM_DIR/versions/node/v7.1.0:/bin:/usr/bin:/usr/local/bin" ] || die "Not correctly changed: $NEW_PATH "
+
+
+EMPTY_PATH=
+
+NEW_PATH=`nvm_change_path "$EMPTY_PATH" "/bin" "$NVM_DIR/versions/node/v4.5.0/bin"`
+
+[ "$NEW_PATH" = "$NVM_DIR/versions/node/v4.5.0/bin" ] || die "Not correctly prepended: $NEW_PATH "

test/fast/Unit tests/nvm_prepend_path

@@ -1,18 +0,0 @@
-#!/bin/sh
-
-die () { echo "$@" ; exit 1; }
-
-\. ../../../nvm.sh
-
-TEST_PATH=/usr/bin:/usr/local/bin
-
-NEW_PATH=`nvm_prepend_path "$TEST_PATH" "$NVM_DIR/v0.2.5/bin"`
-
-[ "$NEW_PATH" = "$NVM_DIR/v0.2.5/bin:/usr/bin:/usr/local/bin" ] || die "Not correctly prepended: $NEW_PATH "
-
-
-EMPTY_PATH=
-
-NEW_PATH=`nvm_prepend_path "$EMPTY_PATH" "$NVM_DIR/v0.2.5/bin"`
-
-[ "$NEW_PATH" = "$NVM_DIR/v0.2.5/bin" ] || die "Not correctly prepended: $NEW_PATH "