Add option to require package.json for node_version segment

powerline_shell/segments/node_version.py

@@ -1,5 +1,5 @@
 import subprocess
-from ..utils import ThreadedSegment
+from ..utils import ThreadedSegment, find_upwards
 
 
 class Segment(ThreadedSegment):
@@ -12,7 +12,14 @@ def run(self):
 
     def add_to_powerline(self):
         self.join()
+
+        require_package = self.powerline.segment_conf("node_version", "require_package", False)
+        chars = int(self.powerline.segment_conf("node_version", "chars", 10))
+        has_package = find_upwards("package.json") != None
+
+        if require_package and not has_package:
+            return
         if not self.version:
             return
         # FIXME no hard-coded colors
-        self.powerline.append("node " + self.version, 15, 18)
+        self.powerline.append(" node " + self.version[:chars] + " ", 15, 18)

powerline_shell/utils.py

@@ -1,6 +1,7 @@
 import sys
 import os
 import threading
+from pathlib import Path
 
 py3 = sys.version_info[0] == 3
 
@@ -150,3 +151,9 @@ def get_git_subprocess_env():
     # Otherwise we may be unable to parse the output.
     return get_subprocess_env(LANG="C")
 
+
+def find_upwards(filename: str, cwd: Path = Path.cwd()) -> Path | None:
+    if cwd == Path(cwd.root) or cwd == cwd.parent:
+        return None
+    fullpath = cwd / filename
+    return fullpath if fullpath.exists() else find_upwards(filename, cwd.parent)