fix(angularls): improves node_modules path resolution #4190

Problem:
Search for node_modules uses a costly call to fn.globpath; the final
path resolution was not working on Linux.

Solution:
A custom function to resolve ngserver location from CMD wrappers on
Windows; and the corrected final path.

Co-authored-by: Erikson K. <erikson23@gmail.com>

1 files changed, 40 insertions, 14 deletions

diff --git a/lsp/angularls.lua b/lsp/angularls.lua
index ec81789f..af82b87a 100644
--- a/lsp/angularls.lua
+++ b/lsp/angularls.lua
@@ -16,6 +16,41 @@
 -- in order to use your projects configured versions.
 local fs, fn, uv = vim.fs, vim.fn, vim.uv
 
+--- Recursively solve for the original ngserver path on Windows
+-- For a given ngserver path:
+--   - If it is not a CMD wrapper, return the path;
+--   - Or else, extract the path from the CMD wrapper.
+--
+-- @param cmd_path (string) path for the ngserver executable or its CMD wrapper.
+-- @return (string) the original executable path for ngserver
+-- @usage
+-- -- Base case: cmd_path already points to ngserver (expected behavior on Linux)
+-- resolve_cmd_shim('/home/user/project/node_modules/@angular/language-server/bin/ngserver')
+-- => '/home/user/project/node_modules/@angular/language-server/bin/ngserver'
+--
+-- -- Recursive case: cmd_path points to a CMD wrapper (Windows)
+-- resolve_cmd_shim('C:/Users/user/project/node_modules/.bin/ngserver.cmd')
+-- => 'C:/Users/user/project/node_modules/@angular/language-server/bin/ngserver'
+local function resolve_cmd_shim(cmd_path)
+  if not cmd_path:lower():match('%ngserver.cmd$') then
+    return cmd_path
+  end
+
+  local ok, content = pcall(fn.readblob, cmd_path)
+  if not ok or not content then
+    return cmd_path
+  end
+
+  local target = content:match('%s%"%%dp0%%\\([^\r\n]-ngserver[^\r\n]-)%"')
+  if not target then
+    return cmd_path
+  end
+
+  local full = fs.normalize(fs.joinpath(fs.dirname(cmd_path), target))
+
+  return resolve_cmd_shim(full)
+end
+
 local function collect_node_modules(root_dir)
   local results = {}
 
@@ -27,16 +62,8 @@ local function collect_node_modules(root_dir)
   local ngserver_exe = fn.exepath('ngserver')
   if ngserver_exe and #ngserver_exe > 0 then
     local realpath = uv.fs_realpath(ngserver_exe) or ngserver_exe
-    local candidate = fs.normalize(fs.joinpath(fs.dirname(realpath), '../../node_modules'))
-    if uv.fs_stat(candidate) then
-      table.insert(results, candidate)
-    end
-  end
-
-  local internal_servers = fn.globpath(fn.stdpath('data'), '**/node_modules/.bin/ngserver', true, true)
-  for _, exe in ipairs(internal_servers) do
-    local realpath = uv.fs_realpath(exe) or exe
-    local candidate = fs.normalize(fs.joinpath(fs.dirname(realpath), '../../node_modules'))
+    realpath = resolve_cmd_shim(realpath)
+    local candidate = fs.normalize(fs.joinpath(fs.dirname(realpath), '../../..'))
     if uv.fs_stat(candidate) then
       table.insert(results, candidate)
     end
@@ -51,13 +78,12 @@ local function get_angular_core_version(root_dir)
     return ''
   end
 
-  local ok, f = pcall(io.open, package_json, 'r')
-  if not ok or not f then
+  local ok, content = pcall(fn.readblob, package_json)
+  if not ok or not content then
     return ''
   end
 
-  local json = vim.json.decode(f:read('*a')) or {}
-  f:close()
+  local json = vim.json.decode(content) or {}
 
   local version = (json.dependencies or {})['@angular/core'] or ''
   return version:match('%d+%.%d+%.%d+') or ''