feat: expose expressions through bindings; (#86)

* feat: expose expressions through bindings;

* fix fmt

bindings/nodejs/src/expression.rs

@@ -0,0 +1,50 @@
+use napi::anyhow::anyhow;
+use napi_derive::napi;
+use serde_json::Value;
+
+use zen_expression::isolate::Isolate;
+
+#[allow(dead_code)]
+#[napi]
+pub async fn evaluate_expression(
+    expression: String,
+    context: Option<Value>,
+) -> napi::Result<Value> {
+    let result: Value = napi::tokio::spawn(async move {
+        let isolate = Isolate::default();
+        if let Some(ctx) = context {
+            isolate.inject_env(&ctx);
+        }
+
+        isolate.run_standard(expression.as_str())
+    })
+    .await
+    .map_err(|_| anyhow!("Hook timed out"))?
+    .map_err(|e| anyhow!(serde_json::to_string(&e).unwrap_or_else(|_| e.to_string())))?;
+
+    Ok(result)
+}
+
+#[allow(dead_code)]
+#[napi]
+pub async fn evaluate_unary_expression(expression: String, context: Value) -> napi::Result<Value> {
+    let Some(context_object) = context.as_object() else {
+        return Err(anyhow!("Context must be an object").into());
+    };
+
+    if !context_object.contains_key("$") {
+        return Err(anyhow!("Context must contain '$' reference.").into());
+    }
+
+    let result: Value = napi::tokio::spawn(async move {
+        let isolate = Isolate::default();
+        isolate.inject_env(&context);
+
+        isolate.run_unary(expression.as_str())
+    })
+    .await
+    .map_err(|_| anyhow!("Hook timed out"))?
+    .map_err(|e| anyhow!(serde_json::to_string(&e).unwrap_or_else(|_| e.to_string())))?;
+
+    Ok(result)
+}

bindings/nodejs/src/lib.rs

@@ -1,3 +1,4 @@
 mod decision;
 mod engine;
+mod expression;
 mod loader;