Add more options to conditionally show node version (#315)

Author: hansl

README.md

@@ -124,7 +124,7 @@ set -g theme_newline_prompt '$ '
 **Prompt options**
 
 - `theme_display_ruby`. Use `no` to completely hide all information about Ruby version. By default Ruby version displayed if there is the difference from default settings.
-- `theme_display_node`. If set to `yes`, will display current NVM or FNM node version.
+- `theme_display_node`. If set to `always`, will display current NPM, NVM or FNM node version. If set to `yes`, will display the version if an `.nvmrc`, `.node-version` or `package.json` file is found in the parent directories.
 - `theme_display_vagrant`. This feature is disabled by default, use `yes` to display Vagrant status in your prompt. Please note that only the VirtualBox and VMWare providers are supported.
 - `theme_display_vi`. By default the vi mode indicator will be shown if vi or hybrid key bindings are enabled. Use `no` to hide the indicator, or `yes` to show the indicator.
 - `theme_display_k8s_context`. This feature is disabled by default. Use `yes` to show the current kubernetes context (`> kubectl config current-context`).

functions/fish_prompt.fish

@@ -895,9 +895,42 @@ function __bobthefish_prompt_desk -S -d 'Display current desk environment'
     set_color normal
 end
 
+function __bobthefish_prompt_find_file_up -S -d 'Find file(s), going up the parent directories'
+    set -l dir "$argv[1]"
+    set -l files $argv[2..]
+
+    if test -z "$dir"
+        or test -z "$files"
+        return 1
+    end
+
+    while [ "$dir" ]
+        for f in $files
+            if [ -e "$dir/$f" ]
+                return
+            end
+        end
+
+        [ "$dir" = '/' ]
+        and return 1
+
+        set dir (__bobthefish_dirname "$dir")
+    end
+    return 1
+end
+
 function __bobthefish_prompt_node -S -d 'Display current node version'
-    [ "$theme_display_node" = 'yes' -o "$theme_display_nvm" = 'yes' ]
-    or return
+    set -l should_show
+
+    if [ "$theme_display_node" = 'always' -o "$theme_display_nvm" = 'yes' ]
+        set should_show 1
+    else if [ "$theme_display_node" = 'yes' ]
+        __bobthefish_prompt_find_file_up "$PWD" package.json .nvmrc .node-version
+        and set should_show 1
+    end
+
+    [ -z "$should_show" ]
+    and return
 
     set -l node_manager
     set -l node_manager_dir