diff --git a/__tests__/dotnet-utils.test.ts b/__tests__/dotnet-utils.test.ts
new file mode 100644
index 0000000..b4d86a5
--- /dev/null
+++ b/__tests__/dotnet-utils.test.ts
@@ -0,0 +1,79 @@
+import * as dotnetUtils from '../src/dotnet-utils';
+import * as exec from '@actions/exec';
+
+describe('dotnet-utils', () => {
+  describe('matchVersionToList', () => {
+    it('matches all versions with all syntaxes correctly', () => {
+      expect(
+        dotnetUtils.matchVersionToList('3.1', ['3.1.201', '6.0.402'])
+      ).toEqual('3.1.201');
+      expect(
+        dotnetUtils.matchVersionToList('3.1.x', ['3.1.201', '6.0.402'])
+      ).toEqual('3.1.201');
+      expect(
+        dotnetUtils.matchVersionToList('3', ['3.1.201', '6.0.402'])
+      ).toEqual('3.1.201');
+      expect(
+        dotnetUtils.matchVersionToList('3.x', ['3.1.201', '6.0.402'])
+      ).toEqual('3.1.201');
+      expect(
+        dotnetUtils.matchVersionToList('6.0.4xx', ['3.1.201', '6.0.402'])
+      ).toEqual('6.0.402');
+    });
+
+    it('returns undefined if no version is matched', () => {
+      expect(
+        dotnetUtils.matchVersionToList('6.0.5xx', ['3.1.201', '6.0.403'])
+      ).toEqual(undefined);
+      expect(dotnetUtils.matchVersionToList('6.0.5xx', [])).toEqual(undefined);
+    });
+
+    it("returns the first version if 'x' or '*' version is provided", () => {
+      expect(
+        dotnetUtils.matchVersionToList('x', ['3.1.201', '6.0.403'])
+      ).toEqual('3.1.201');
+      expect(
+        dotnetUtils.matchVersionToList('*', ['3.1.201', '6.0.403'])
+      ).toEqual('3.1.201');
+    });
+
+    it('returns undefined if empty version list is provided', () => {
+      expect(dotnetUtils.matchVersionToList('6.0.4xx', [])).toEqual(undefined);
+    });
+  });
+
+  describe('listSdks', () => {
+    const execSpy = jest.spyOn(exec, 'getExecOutput');
+
+    it('correctly parses versions from output and sorts them from newest to oldest', async () => {
+      const stdout = `
+        2.2.207 [C:\\Users\\User_Name\\AppData\\Local\\Microsoft\\dotnet\\sdk]
+        6.0.413 [C:\\Users\\User_Name\\AppData\\Local\\Microsoft\\dotnet\\sdk]
+        6.0.414 [C:\\Users\\User_Name\\AppData\\Local\\Microsoft\\dotnet\\sdk]
+      `;
+
+      execSpy.mockImplementationOnce(() =>
+        Promise.resolve({stdout, exitCode: 0, stderr: ''})
+      );
+      expect(await dotnetUtils.listSdks()).toEqual([
+        '6.0.414',
+        '6.0.413',
+        '2.2.207'
+      ]);
+    });
+
+    it('returns empty array if exit code is not 0', async () => {
+      execSpy.mockImplementationOnce(() =>
+        Promise.resolve({stdout: '', exitCode: 1, stderr: 'arbitrary error'})
+      );
+      expect(await dotnetUtils.listSdks()).toEqual([]);
+    });
+
+    it('returns empty array on error', async () => {
+      execSpy.mockImplementationOnce(() =>
+        Promise.reject(new Error('arbitrary error'))
+      );
+      expect(await dotnetUtils.listSdks()).toEqual([]);
+    });
+  });
+});