New build infra

Build/lib/string-array-compare.js

@@ -0,0 +1,35 @@
+const { promises: fsPromises } = require('fs');
+
+async function compareAndWriteFile(linesA, filePath) {
+  const linesB = (await fsPromises.readFile(filePath, { encoding: 'utf-8' })).split('\n');
+
+  if (!stringArrayCompare(linesA, linesB)) {
+    await fsPromises.writeFile(
+      filePath,
+      linesA.join('\n'),
+      { encoding: 'utf-8' }
+    )
+  } else {
+    console.log(`Same Content, bail out writing: ${filePath}`);
+  }
+}
+
+function stringArrayCompare (linesA, linesB) {
+  if (linesA.length !== linesB.length) return false;
+
+  for (let i = 0; i < linesA.length; i++) {
+    const lineA = linesA[i];
+    const lineB = linesB[i];
+    if (lineA.startsWith('#') && lineB.startsWith('#')) {
+      continue;
+    }
+    if (lineA !== lineB) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+module.exports.stringArrayCompare = stringArrayCompare;
+module.exports.compareAndWriteFile = compareAndWriteFile;