diff --git a/Tests/FigmaExportCoreTests/Extensions/StringCaseTests.swift b/Tests/FigmaExportCoreTests/Extensions/StringCaseTests.swift
new file mode 100644
index 00000000..430a76f3
--- /dev/null
+++ b/Tests/FigmaExportCoreTests/Extensions/StringCaseTests.swift
@@ -0,0 +1,34 @@
+import XCTest
+@testable import FigmaExportCore
+
+final class StringCaseTests: XCTestCase {
+    
+    func testSnakeCase() throws {
+        XCTAssertTrue("snake".isSnakeCase)
+        XCTAssertTrue("snake_case".isSnakeCase)
+        XCTAssertTrue("snake_case_example".isSnakeCase)
+        XCTAssertFalse("not_a_SNAKECASE_String".isSnakeCase)
+        XCTAssertFalse("notSnakeCase".isSnakeCase)
+        XCTAssertFalse("AlsoNotSnakeCase".isSnakeCase)
+        
+        XCTAssertEqual("snake".snakeCased(), "snake")
+        XCTAssertEqual("snake cased".snakeCased(), "snake_cased")
+        XCTAssertEqual("snakeCased".snakeCased(), "snake_cased")
+        XCTAssertEqual("snake Cased_String".snakeCased(), "snake_cased_string")
+        XCTAssertEqual("_this is*  not-Very%difficult".snakeCased(), "this_is_not_very_difficult")
+    }
+    
+    func testLowerCamelCase() throws {
+        XCTAssertTrue("lower".isLowerCamelCase)
+        XCTAssertTrue("lowerCamelCase".isLowerCamelCase)
+        XCTAssertFalse("lowerCamelCase_with_underscore".isLowerCamelCase)
+        XCTAssertFalse("UpperCamelCase".isLowerCamelCase)
+        XCTAssertFalse("snake_case".isLowerCamelCase)
+        
+        XCTAssertEqual("lower".lowerCamelCased(), "lower")
+        XCTAssertEqual("LowerCamelCased".lowerCamelCased(), "lowerCamelCased")
+        XCTAssertEqual("lower_camel_cased".lowerCamelCased(), "lowerCamelCased")
+        XCTAssertEqual("Lower Camel cased".lowerCamelCased(), "lowerCamelCased")
+        XCTAssertEqual("_this is*  not-Very%difficult".lowerCamelCased(), "thisIsNotVeryDifficult")
+    }
+}