Decouple core Yaak logic from Tauri (#354)

crates/yaak-templates/src/error.rs

@@ -0,0 +1,32 @@
+use serde::{Serialize, Serializer};
+use thiserror::Error;
+use wasm_bindgen::JsValue;
+
+#[derive(Error, Debug, PartialEq)]
+pub enum Error {
+    #[error("Render Error: {0}")]
+    RenderError(String),
+
+    #[error("Render Error: Variable \"{0}\" is not defined in active environment")]
+    VariableNotFound(String),
+
+    #[error("Render Error: Max recursion depth exceeded")]
+    RenderStackExceededError,
+}
+
+impl Serialize for Error {
+    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(self.to_string().as_ref())
+    }
+}
+
+impl Into<JsValue> for Error {
+    fn into(self) -> JsValue {
+        serde_wasm_bindgen::to_value(&self).unwrap()
+    }
+}
+
+pub type Result<T> = std::result::Result<T, Error>;