diff --git a/packages/core/src/utils/case.test.ts b/packages/core/src/utils/case.test.ts
new file mode 100644
index 000000000..13b0680be
--- /dev/null
+++ b/packages/core/src/utils/case.test.ts
@@ -0,0 +1,28 @@
+import { describe, expect, it } from 'vitest';
+import { pascal } from './case';
+
+describe('pascal case testing', () => {
+  it('should convert to pascal case', () => {
+    expect(pascal('PascalCase')).toBe('PascalCase');
+    expect(pascal('camelCase')).toBe('CamelCase');
+    expect(pascal('kebab-case')).toBe('KebabCase');
+    expect(pascal('snake_case')).toBe('SnakeCase');
+    expect(pascal('point.case')).toBe('PointCase');
+    expect(pascal('UPPER_CASE')).toBe('UpperCase');
+    expect(pascal('DrUn-k_CaSE')).toBe('DrUnKCaSE');
+  });
+
+  it('should convert to pascal case with underscore', () => {
+    expect(pascal('_camelCase')).toBe('_CamelCase');
+    expect(pascal('_kebab-case')).toBe('_KebabCase');
+  });
+
+  it('should convert to pascal case when more complex input is given', () => {
+    expect(pascal('camelCase_')).toBe('CamelCase');
+    expect(pascal('more complex input')).toBe('MoreComplexInput');
+  });
+
+  it('should handle some casing edge cases', () => {
+    expect(pascal('foo_bar_API')).toBe('FooBarAPI');
+  });
+});
diff --git a/packages/core/src/utils/case.ts b/packages/core/src/utils/case.ts
index be56b1f89..f45a492b2 100644
--- a/packages/core/src/utils/case.ts
+++ b/packages/core/src/utils/case.ts
@@ -43,12 +43,11 @@ const deapostrophe = (s: string) => {
 const up = String.prototype.toUpperCase;
 const low = String.prototype.toLowerCase;
 
-const fill = (s: string, fillWith?: string, isDeapostrophe = false) => {
-  if (fillWith != null) {
-    s = s.replace(regexps.fill, function (m, next) {
-      return next ? fillWith + next : '';
-    });
-  }
+const fill = (s: string, fillWith: string, isDeapostrophe = false) => {
+  s = s.replace(regexps.fill, function (m, next) {
+    return next ? fillWith + next : '';
+  });
+
   if (isDeapostrophe) {
     s = deapostrophe(s);
   }
@@ -92,16 +91,13 @@ const lower = (s: string, fillWith: string, isDeapostrophe: boolean) => {
 export const pascal = (s: string) => {
   const isStartWithUnderscore = s?.startsWith('_');
 
-  const pascalString = fill(
-    prep(s, false, true).replace(
-      regexps.pascal,
-      (m: string, border: string, letter: string) => {
-        return up.call(letter);
-      },
-    ),
-    '',
-    true,
-  );
+  if (regexps.upper.test(s)) {
+    s = low.call(s);
+  }
+
+  const pascalString = (s.match(/[a-zA-Z0-9]+/g) || [])
+    .map((w) => w.charAt(0).toUpperCase() + w.slice(1))
+    .join('');
 
   return isStartWithUnderscore ? `_${pascalString}` : pascalString;
 };
@@ -122,7 +118,7 @@ export const kebab = (s: string) => {
 
 export const upper = (
   s: string,
-  fillWith?: string,
+  fillWith: string,
   isDeapostrophe?: boolean,
 ) => {
   return fill(