🧪 Add unit tests for register_image and std.image module

stdlib/src/image.rs

@@ -103,3 +103,128 @@ impl StdlibRegistry {
         );
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use techscript_runtime::context::{RuntimeConfig, RuntimeContext};
+
+    #[test]
+    fn test_register_image() {
+        let mut registry = StdlibRegistry::default();
+        registry.register_image();
+
+        assert!(registry.has_module("std.image"));
+        let module = registry.get_module("std.image").unwrap();
+        assert_eq!(module.name, "std.image");
+        assert_eq!(module.version, "1.0.0");
+        assert!(module.required_capabilities.is_empty());
+
+        assert_eq!(module.exports.len(), 3);
+        assert_eq!(module.exports.get("open").unwrap().arity(), 1);
+        assert_eq!(module.exports.get("resize").unwrap().arity(), 3);
+        assert_eq!(module.exports.get("grayscale").unwrap().arity(), 1);
+    }
+
+    #[test]
+    fn test_image_open_and_errors() {
+        let mut registry = StdlibRegistry::default();
+        registry.register_image();
+        let module = registry.get_module("std.image").unwrap();
+        let open_fn = module.exports.get("open").unwrap();
+
+        let mut ctx = RuntimeContext::new(RuntimeConfig::default());
+
+        // Error path: file does not exist
+        let err_res = open_fn.call(
+            &mut ctx,
+            vec![RuntimeValue::Str("non_existent_file_9999.png".to_string())],
+        );
+        assert!(err_res.is_err());
+
+        // Success path: create a temporary 10x20 image
+        let temp_dir = std::env::temp_dir();
+        let test_img_path = temp_dir.join("techscript_test_open.png");
+        let img = image::RgbImage::new(10, 20);
+        img.save(&test_img_path).expect("failed to save temp image");
+
+        let res = open_fn.call(
+            &mut ctx,
+            vec![RuntimeValue::Str(
+                test_img_path.to_str().unwrap().to_string(),
+            )],
+        );
+        assert!(res.is_ok());
+        if let Ok(RuntimeValue::Str(val)) = res {
+            assert_eq!(val, "image 10x20");
+        } else {
+            panic!("expected RuntimeValue::Str");
+        }
+
+        let _ = std::fs::remove_file(test_img_path);
+    }
+
+    #[test]
+    fn test_image_resize() {
+        let mut registry = StdlibRegistry::default();
+        registry.register_image();
+        let module = registry.get_module("std.image").unwrap();
+        let resize_fn = module.exports.get("resize").unwrap();
+
+        let mut ctx = RuntimeContext::new(RuntimeConfig::default());
+
+        let temp_dir = std::env::temp_dir();
+        let test_img_path = temp_dir.join("techscript_test_resize.png");
+        let img = image::RgbImage::new(20, 20);
+        img.save(&test_img_path).expect("failed to save temp image");
+
+        let res = resize_fn.call(
+            &mut ctx,
+            vec![
+                RuntimeValue::Str(test_img_path.to_str().unwrap().to_string()),
+                RuntimeValue::Int(10),
+                RuntimeValue::Int(15),
+            ],
+        );
+        assert!(res.is_ok());
+        if let Ok(RuntimeValue::Str(out_path)) = res {
+            assert!(std::path::Path::new(&out_path).exists());
+            let _ = std::fs::remove_file(&out_path);
+        } else {
+            panic!("expected RuntimeValue::Str");
+        }
+
+        let _ = std::fs::remove_file(test_img_path);
+    }
+
+    #[test]
+    fn test_image_grayscale() {
+        let mut registry = StdlibRegistry::default();
+        registry.register_image();
+        let module = registry.get_module("std.image").unwrap();
+        let grayscale_fn = module.exports.get("grayscale").unwrap();
+
+        let mut ctx = RuntimeContext::new(RuntimeConfig::default());
+
+        let temp_dir = std::env::temp_dir();
+        let test_img_path = temp_dir.join("techscript_test_gray.png");
+        let img = image::RgbImage::new(20, 20);
+        img.save(&test_img_path).expect("failed to save temp image");
+
+        let res = grayscale_fn.call(
+            &mut ctx,
+            vec![RuntimeValue::Str(
+                test_img_path.to_str().unwrap().to_string(),
+            )],
+        );
+        assert!(res.is_ok());
+        if let Ok(RuntimeValue::Str(out_path)) = res {
+            assert!(std::path::Path::new(&out_path).exists());
+            let _ = std::fs::remove_file(&out_path);
+        } else {
+            panic!("expected RuntimeValue::Str");
+        }
+
+        let _ = std::fs::remove_file(test_img_path);
+    }
+}