add a GitHub workflow to check cspell lists

scripts/sort_and_unique_file_lines.js

@@ -1,10 +1,13 @@
-import fs from "node:fs";
 import path from "node:path";
 
 const filePath = process.argv[2];
+const check = process.argv[3] === "--check";
 
 if (!fs.existsSync(filePath)) {
   console.error(`File ${filePath} doesn't exist.`);
+  console.warn(
+    "Usage:\n\tnode scripts/sort_and_unique_file_lines.js <filePath> [--check]",
+  );
   process.exit(1);
 }
 
@@ -13,14 +16,12 @@ function equalsIgnoreCase(string1, string2) {
 }
 
 const uniq = [];
-const lines = fs
-  .readFileSync(filePath, "utf-8")
-  .split("\n")
-  .sort((a, b) => {
-    a = a.toUpperCase();
-    b = b.toUpperCase();
-    return a < b ? -1 : a > b ? 1 : 0;
-  });
+const content = fs.readFileSync(filePath, "utf-8");
+const lines = content.split("\n").sort((a, b) => {
+  a = a.toUpperCase();
+  b = b.toUpperCase();
+  return a < b ? -1 : a > b ? 1 : 0;
+});
 
 for (let i = 0; i < lines.length; ) {
   const line = lines[i];
@@ -32,4 +33,17 @@ for (let i = 0; i < lines.length; ) {
   }
 }
 
-fs.writeFileSync(filePath, uniq.join("\n"));
+const sortedContent = uniq.join("\n") + "\n";
+if (check) {
+  if (content !== sortedContent) {
+    console.error(
+      `The file is not formatted properly. Run 'node scripts/sort_and_unique_file_lines.js ${filePath}' to format the file.`,
+    );
+    process.exit(1);
+  } else {
+    console.log("The file looks good.");
+    process.exit(0);
+  }
+}
+
+fs.writeFileSync(filePath, sortedContent);