chore: improve code cov

# Conflicts:
#	src/__tests__/compiler.test.tsx

Author: mdjastrzebski

src/__tests__/compiler.test.tsx

@@ -49,3 +49,10 @@ test('"buildPattern" escapes special characters', () => {
     '(?:\\.\\*)+(?:\\[\\]\\{\\})*'
   );
 });
+
+test('buildRegex throws error on unknown element', () => {
+  expect(() =>
+    // @ts-expect-error intentionally passing incorrect object
+    buildRegex({ type: 'unknown' })
+  ).toThrowErrorMatchingInlineSnapshot(`"Unknown elements type unknown"`);
+});

src/compiler.ts

@@ -39,13 +39,13 @@ function compileSingle(element: RegexElement): string {
     return characterClasses[element.type];
   }
 
-  const compiledChildren = compileList(element.children);
-
   if (element.type === 'repeat') {
+    const compiledChildren = compileList(element.children);
     return compileRepeat(element.config, compiledChildren);
   }
 
   if (isBaseQuantifier(element)) {
+    const compiledChildren = compileList(element.children);
     const compiler = baseQuantifiers[element.type];
     return compiler(compiledChildren);
   }