Add support for Windows .cmd and .bat files (#570)

## Summary

I use ruff for our embedded python interpreter. This interpreter needs
to be bootstrapped (env-vars) before be able to get called (technical
limit of the environment itself).
This is usually done with `.cmd` file (the modern version of `.bat`) on
windows which is kind of similar to `.sh` on linux.
`.cmd` files are often use on Windows, even vscode itself use it to
start vscode on windows.

Today I noticed that I get a crash when using the `.cmd` interpreter
path.

It seems that node require shell mode (in windows calling `cmd.exe` as
the shell) to be able to call `.cmd` files correctly.
I needed to quote the input filename as well to avoid whitespace issues
which looks like a bug in node itself.

With that PR I got no crashes anymore when the extension try to run ruff
😄 .

Note: The shell mode only get activated when the platform is windows and
the file extension is `.cmd`, so users with regular executables should
not be affected at all.

## Test Plan

Manual testing it locally works great and as expected.

I added a utils-test to check the require shell mode flag.

The PR is related to the changes of #539

---------

Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>

src/common/server.ts

@@ -1,5 +1,6 @@
 import * as fsapi from "fs-extra";
 import * as vscode from "vscode";
+import { platform } from "os";
 import { Disposable, l10n, LanguageStatusSeverity, LogOutputChannel } from "vscode";
 import { State } from "vscode-languageclient";
 import {
@@ -44,12 +45,25 @@ export type IInitializationOptions = {
   globalSettings: ISettings;
 };
 
+/**
+ * Check if shell mode is required for `execFile`.
+ *
+ * The conditions are:
+ * - Windows OS
+ * - File extension is `.cmd` or `.bat`
+ */
+export function execFileShellModeRequired(file: string) {
+  file = file.toLowerCase();
+  return platform() === "win32" && (file.endsWith(".cmd") || file.endsWith(".bat"));
+}
+
 /**
  * Function to execute a command and return the stdout.
  */
 function executeFile(file: string, args: string[] = []): Promise<string> {
+  const shell = execFileShellModeRequired(file);
   return new Promise((resolve, reject) => {
-    execFile(file, args, (error, stdout, stderr) => {
+    execFile(shell ? `"${file}"` : file, args, { shell }, (error, stdout, stderr) => {
       if (error) {
         reject(new Error(stderr || error.message));
       } else {

src/test/helper.ts

@@ -1,5 +1,6 @@
 import * as vscode from "vscode";
 import * as path from "path";
+import { platform } from "os";
 
 const EXTENSION_ID = "charliermarsh.ruff";
 
@@ -26,3 +27,7 @@ export const getDocumentPath = (p: string) => {
 export const getDocumentUri = (p: string) => {
   return vscode.Uri.file(getDocumentPath(p));
 };
+
+export const isWindows = () => {
+  return platform() === "win32";
+};

src/test/utils.test.ts

@@ -0,0 +1,28 @@
+import * as assert from "assert";
+import { execFileShellModeRequired } from "../common/server";
+import { isWindows } from "./helper";
+
+suite("Utils tests", () => {
+  test("Check execFile shell mode", () => {
+    assert.strictEqual(
+      execFileShellModeRequired("/use/random/python"),
+      false,
+      "Shell mode should not be required for unix paths",
+    );
+    assert.strictEqual(
+      execFileShellModeRequired("C:\\random\\python.exe"),
+      false,
+      "Shell mode should not be required for .exe files",
+    );
+    assert.strictEqual(
+      execFileShellModeRequired("C:\\random\\python.cmd"),
+      isWindows(),
+      "Shell mode should be required for .cmd files",
+    );
+    assert.strictEqual(
+      execFileShellModeRequired("C:\\random\\python.bat"),
+      isWindows(),
+      "Shell mode should be required for .bat files",
+    );
+  });
+});