add swift test cases

Package.swift

@@ -52,7 +52,7 @@ var omniVlmSources = [
 ]
 
 var testSources = [
-   "tests/LlavaTests/LlavaTests.swift"
+   "swift/LlavaTests/LlavaTests.swift"
 ]
 
 var resources: [Resource] = []

swift/LlavaTests/LlavaTests.swift

@@ -0,0 +1,27 @@
+import XCTest
+@testable import omnivlm
+
+final class LlavaTests: XCTestCase {
+    func testOmniVlm() {
+        omnivlm_init("/Users/liute/Downloads/model-q4_0.gguf",
+                     "/Users/liute/Downloads/projector-q4_0.gguf",
+                     "vlm-81-instruct")
+
+        let startTime = Date()
+
+        if let cString = omnivlm_inference("describe the image", "/Users/liute/Downloads/cat.png") {
+            let res = String(cString: cString)
+            print("res: \(res)")
+            
+            let endTime = Date()
+            let inferenceTime = endTime.timeIntervalSince(startTime)
+            print("Inference time: \(inferenceTime) seconds")
+
+            XCTAssertFalse(res.isEmpty, "res should not be null")
+        } else {
+            XCTFail("failed")
+        }
+        
+        omnivlm_free()
+    }
+}