plugins/nvm: Add nvmrc autoload option

Fixes https://github.com/ohmybash/oh-my-bash/pull/371

plugins/nvm/README.md

@@ -36,5 +36,16 @@ completions=(
 )
 ```
 
+## `.nvmrc` autoload
+
+If set, the plugin will automatically load a node version when if finds a
+`.nvmrc` file[3] in the current working directory indicating which node version to load.
+This can be done adding the following to your `.bashrc`:
+
+```bash
+export OMB_PLUGIN_NVM_AUTO_USE=true
+```
+
 [1]: https://github.com/nvm-sh/nvm
 [2]: https://github.com/nvm-sh/nvm#manual-install
+[3]: https://github.com/nvm-sh/nvm#nvmrc

plugins/nvm/nvm.plugin.sh

@@ -1,4 +1,7 @@
 #! bash oh-my-bash.module
+# Description: automatically load nvm 
+#
+# @var[opt] OMB_PLUGIN_NVM_AUTO_USE enable .nvmrc autoload
 
 # Set NVM_DIR if it isn't already defined
 [[ -z "$NVM_DIR" ]] && export NVM_DIR="$HOME/.nvm"
@@ -6,7 +9,60 @@
 
 # Try to load nvm only if command not already available
 if ! _omb_util_command_exists nvm; then
-  [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
-  # This is done as part of completions!!!
-  # [ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion
+  # shellcheck source=/dev/null
+  [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
+fi
+
+# Optional .nvmrc autoload
+if _omb_util_command_exists nvm && [[ ${OMB_PLUGIN_NVM_AUTO_USE} == true ]]; then
+  find-up () {
+    path=$(pwd)
+    while [[ "$path" != "" && ! -e "$path/$1" ]]; do
+        path=${path%/*}
+    done
+    echo "$path"
+  }
+  
+  cdnvm(){
+    cd "$@" || return $?
+    nvm_path=$(find-up .nvmrc | tr -d '\n')
+
+    # If there are no .nvmrc file, use the default nvm version
+    if [[ ! $nvm_path = *[^[:space:]]* ]]; then
+
+      declare default_version;
+      default_version=$(nvm version default);
+
+      # If there is no default version, set it to `node`
+      # This will use the latest version on your machine
+      if [[ $default_version == "N/A" ]]; then
+          nvm alias default node;
+          default_version=$(nvm version default);
+      fi
+
+      # If the current version is not the default version, set it to use the default version
+      if [[ $(nvm current) != "$default_version" ]]; then
+          nvm use default;
+      fi
+
+    elif [[ -s $nvm_path/.nvmrc && -r $nvm_path/.nvmrc ]]; then
+      declare nvm_version
+      nvm_version=$(<"$nvm_path"/.nvmrc)
+
+      # Add the `v` suffix if it does not exists in the .nvmrc file
+      if [[ $nvm_version != v* ]]; then
+          nvm_version="v""$nvm_version"
+      fi
+
+      # If it is not already installed, install it
+      if [[ $(nvm ls "$nvm_version" | tr -d '[:space:]') == "N/A" ]]; then
+          nvm install "$nvm_version";
+      fi
+
+      if [[ $(nvm current) != "$nvm_version" ]]; then
+          nvm use "$nvm_version";
+      fi
+    fi
+  }
+  alias cd='cdnvm'
 fi