Try replacing sh.cat with native file reading

See if such replacement works well on a Windows machine.

Author: vmarta

scripts/smoke-test-npm-scripts.js

@@ -26,10 +26,18 @@ program.parse(process.argv)
 
 const main = () => {
     const opts = program.opts()
-
     const cwd = path.resolve(opts.dir)
 
-    const pkg = JSON.parse(sh.cat(path.join(cwd, 'package.json')))
+    let pkg
+    const packageJson = path.join(cwd, 'package.json')
+
+    try {
+        pkg = JSON.parse(fs.readFileSync(packageJson))
+    } catch (err) {
+        console.error(`Error reading or parsing ${packageJson}:`)
+        console.error(err)
+        sh.exit(1)
+    }
 
     // The excluded scripts are either already part of our CI steps or are not safe to run.
     const exclude = [