fix: refactor handleRegularCharacter to eliminate invariant return

Resolves SonarQube code smell S3516 by removing redundant if-else
branches that both returned the same value. The function now advances
the position unconditionally and only conditionally updates line/column
tracking for newlines before returning the character once at the end.

This maintains identical behavior while improving code maintainability.

Author: claude

package-lock.json

@@ -457,15 +457,12 @@ export class Lexer {
 
   private handleRegularCharacter(): string {
     const char = this.currentChar();
+    this.advance();
     if (char === '\n') {
-      this.advance();
       this.line++;
       this.column = 1;
-      return char;
-    } else {
-      this.advance();
-      return char;
     }
+    return char;
   }
 
   private readNumber(startLine: number, startColumn: number): Token {

src/lexer.ts

@@ -231,7 +231,8 @@ export class ModuleSystem {
     // Try to extract line and column from error message
     const lineColMatch = message.match(/(?:line|:)\s*(\d+)(?::(\d+))?/i);
     const line = lineColMatch ? Number.parseInt(lineColMatch[1], 10) : undefined;
-    const column = lineColMatch && lineColMatch[2] ? Number.parseInt(lineColMatch[2], 10) : undefined;
+    const column =
+      lineColMatch && lineColMatch[2] ? Number.parseInt(lineColMatch[2], 10) : undefined;
 
     return {
       message,

src/module-system/module-system.ts

@@ -69,20 +69,19 @@ export interface CliRunOptions {
 
 /** Run a CLI command with common defaults */
 export function runCliCommand(options: CliRunOptions): SpawnSyncReturns<string> {
-  return spawnSync(
-    process.execPath,
-    [CLI_PATH, options.command, ...options.args],
-    {
-      encoding: options.encoding || 'utf-8',
-      timeout: options.timeout || 10000,
-      cwd: options.cwd,
-      env: options.env || process.env,
-    }
-  );
+  return spawnSync(process.execPath, [CLI_PATH, options.command, ...options.args], {
+    encoding: options.encoding || 'utf-8',
+    timeout: options.timeout || 10000,
+    cwd: options.cwd,
+    env: options.env || process.env,
+  });
 }
 
 /** Create a test .som file with given content */
-export function createTestFile(filePath: string, content: string = TEST_FIXTURES.testFunction): void {
+export function createTestFile(
+  filePath: string,
+  content: string = TEST_FIXTURES.testFunction
+): void {
   fs.writeFileSync(filePath, content);
 }