[check_config] refactor: improve error handling and user experience

- Combine duplicate file existence checks to prevent edge cases
- Display clean error messages without technical stack traces
- Distinguish between "file not found" and "permission denied" errors
- Use consistent [checkconfig] prefix for all messages
- Fix missing exit after module validation errors

Users now see clear, actionable error messages instead of confusing technical output when their config file has issues.

Author: KristjanESPERANTO

CHANGELOG.md

@@ -18,6 +18,7 @@ planned for 2026-01-01
 ### Changed
 
 - [core] refactor: replace `module-alias` dependency with internal alias resolver (#3893)
+- [check_config] refactor: improve error handling and user experience (#3927)
 
 ### Fixed
 

js/check_config.js

@@ -31,20 +31,22 @@ function getConfigFile () {
 function checkConfigFile () {
 	const configFileName = getConfigFile();
 
-	// Check if file is present
-	if (fs.existsSync(configFileName) === false) {
-		throw new Error(`File not found: ${configFileName}\nNo config file present!`);
-	}
-
-	// Check permission
+	// Check if file exists and is accessible
 	try {
-		fs.accessSync(configFileName, fs.constants.F_OK);
+		fs.accessSync(configFileName, fs.constants.R_OK);
 	} catch (error) {
-		throw new Error(`${error}\nNo permission to access config file!`);
+		if (error.code === "ENOENT") {
+			Log.error(`[check_config] File not found: ${configFileName}`);
+		} else if (error.code === "EACCES") {
+			Log.error(`[check_config] No permission to read config file: ${configFileName}`);
+		} else {
+			Log.error(`[check_config] Cannot access config file: ${configFileName}\n${error.message}`);
+		}
+		process.exit(1);
 	}
 
 	// Validate syntax of the configuration file.
-	Log.info(`[checkconfig] Checking config file ${configFileName} ...`);
+	Log.info(`[check_config] Checking config file ${configFileName} ...`);
 
 	// I'm not sure if all ever is utf-8
 	const configFile = fs.readFileSync(configFileName, "utf-8");
@@ -67,15 +69,16 @@ function checkConfigFile () {
 	);
 
 	if (errors.length === 0) {
-		Log.info(styleText("green", "[checkconfig] Your configuration file doesn't contain syntax errors :)"));
+		Log.info(styleText("green", "[check_config] Your configuration file doesn't contain syntax errors :)"));
 		validateModulePositions(configFileName);
 	} else {
-		let errorMessage = "Your configuration file contains syntax errors :(";
+		let errorMessage = "[check_config] Your configuration file contains syntax errors :(";
 
 		for (const error of errors) {
 			errorMessage += `\nLine ${error.line} column ${error.column}: ${error.message}`;
 		}
-		throw new Error(errorMessage);
+		Log.error(errorMessage);
+		process.exit(1);
 	}
 }
 
@@ -84,7 +87,7 @@ function checkConfigFile () {
  * @param {string} configFileName - The path and filename of the configuration file to validate.
  */
 function validateModulePositions (configFileName) {
-	Log.info("[checkconfig] Checking modules structure configuration ...");
+	Log.info("[check_config] Checking modules structure configuration ...");
 
 	const positionList = Utils.getModulePositions();
 
@@ -118,7 +121,7 @@ function validateModulePositions (configFileName) {
 
 	const valid = validate(data);
 	if (valid) {
-		Log.info(styleText("green", "[checkconfig] Your modules structure configuration doesn't contain errors :)"));
+		Log.info(styleText("green", "[check_config] Your modules structure configuration doesn't contain errors :)"));
 	} else {
 		const module = validate.errors[0].instancePath.split("/")[2];
 		const position = validate.errors[0].instancePath.split("/")[3];
@@ -130,13 +133,15 @@ function validateModulePositions (configFileName) {
 		} else {
 			errorMessage += validate.errors[0].message;
 		}
-		Log.error("[checkconfig]", errorMessage);
+		Log.error("[check_config]", errorMessage);
+		process.exit(1);
 	}
 }
 
 try {
 	checkConfigFile();
 } catch (error) {
-	Log.error("[checkconfig]", error);
+	const message = error && error.message ? error.message : error;
+	Log.error(`[check_config] Unexpected error: ${message}`);
 	process.exit(1);
 }