Added snake_case CLI enforcement

Author: bradhanson

generate.js

@@ -14,22 +14,35 @@
 const fs = require('fs');
 const path = require('path');
 
+const selfName = path.basename(process.argv[1]); // e.g., generate.js
+
+// Enforce proper command line usage with exactly 1 parameter
 if (process.argv.length !== 3) {
-    let selfName = path.basename(process.argv[1]);
-    console.error('Usage: node %s <file>', selfName);
+    console.error('Usage: node %s <file_name>', selfName);
     // https://nodejs.org/api/process.html#process_process_exit_code
     // https://nodejs.org/api/process.html#process_exit_codes
     // A bit better to set exit code and let program exit naturally
     process.exit(9);
 }
 
-let fileName = path.basename(process.argv[2]);
-let filePath = path.dirname(process.argv[2]);
+const fileName = path.basename(process.argv[2]); // e.g., ab_check
+const filePath = path.dirname(process.argv[2]);
+
+// Enforce snake_case
+let snakeCaseRegEx = /^[a-z]+[_a-z0-9]*[a-z0-9]+$/;
+if (!snakeCaseRegEx.test(fileName)) {
+    console.error(
+        'Usage: node %s <file_name>\n  <file_name>: must be in snake_case',
+        selfName
+    );
+    process.exit(9);
+}
 
 let fileNameCamelCase = fileName.replace(/[_]([a-z])/g, (_, letter) =>
     letter.toUpperCase()
 );
 
+// File templates
 let codeFileContent = `/**
  *
  * @param  {type} param
@@ -49,6 +62,7 @@ describe('${fileNameCamelCase}()', () => {
     });
 });`;
 
+// File write logic
 let codeFileName = path.join(filePath, fileName) + '.js';
 let testFileName = path.join(filePath, fileName) + '.test.js';