feat: add TransactionContext type (#5)

* feat: add TransactionContext type

* Update src/tracing/js/mod.rs

Co-authored-by: Enrique <[email protected]>

---------

Co-authored-by: Enrique <[email protected]>

src/tracing/js/bindings.rs

@@ -6,7 +6,7 @@ use crate::tracing::{
             address_to_buf, bytes_to_address, bytes_to_hash, from_buf, to_bigint, to_buf,
             to_buf_value,
         },
-        JsDbRequest,
+        JsDbRequest, TransactionContext,
     },
     types::CallKind,
 };
@@ -624,9 +624,7 @@ pub(crate) struct EvmContext {
     pub(crate) output: Bytes,
     /// Number, block number
     pub(crate) time: String,
-    pub(crate) block_hash: Option<B256>,
-    pub(crate) tx_index: Option<usize>,
-    pub(crate) tx_hash: Option<B256>,
+    pub(crate) transaction_ctx: TransactionContext,
 }
 
 impl EvmContext {
@@ -644,9 +642,7 @@ impl EvmContext {
             block,
             output,
             time,
-            block_hash,
-            tx_index,
-            tx_hash,
+            transaction_ctx,
         } = self;
         let obj = JsObject::default();
 
@@ -669,13 +665,13 @@ impl EvmContext {
         obj.set("block", block, false, ctx)?;
         obj.set("output", to_buf(output.to_vec(), ctx)?, false, ctx)?;
         obj.set("time", time, false, ctx)?;
-        if let Some(block_hash) = block_hash {
+        if let Some(block_hash) = transaction_ctx.block_hash {
             obj.set("blockHash", to_buf(block_hash.as_slice().to_vec(), ctx)?, false, ctx)?;
         }
-        if let Some(tx_index) = tx_index {
+        if let Some(tx_index) = transaction_ctx.tx_index {
             obj.set("txIndex", tx_index as u64, false, ctx)?;
         }
-        if let Some(tx_hash) = tx_hash {
+        if let Some(tx_hash) = transaction_ctx.tx_hash {
             obj.set("txHash", to_buf(tx_hash.as_slice().to_vec(), ctx)?, false, ctx)?;
         }
 

src/tracing/js/mod.rs

@@ -31,9 +31,13 @@ pub(crate) mod builtins;
 pub struct JsInspector {
     ctx: Context<'static>,
     /// The javascript config provided to the inspector.
-    _config: JsValue,
+    _js_config_value: JsValue,
+    /// The input config object.
+    config: serde_json::Value,
     /// The evaluated object that contains the inspector functions.
     obj: JsObject,
+    /// The context of the transaction that is being inspected.
+    transaction_context: TransactionContext,
 
     /// The javascript function that will be called when the result is requested.
     result_fn: JsObject,
@@ -80,6 +84,19 @@ impl JsInspector {
         code: String,
         config: serde_json::Value,
         to_db_service: mpsc::Sender<JsDbRequest>,
+    ) -> Result<Self, JsInspectorError> {
+        Self::with_transaction_context(code, config, to_db_service, Default::default())
+    }
+
+    /// Creates a new inspector from a javascript code snippet. See also [Self::new].
+    ///
+    /// This also accepts a [TransactionContext] that gives the JS code access to some contextual
+    /// transaction infos.
+    pub fn with_transaction_context(
+        code: String,
+        config: serde_json::Value,
+        to_db_service: mpsc::Sender<JsDbRequest>,
+        transaction_context: TransactionContext,
     ) -> Result<Self, JsInspectorError> {
         // Instantiate the execution context
         let mut ctx = Context::default();
@@ -116,7 +133,7 @@ impl JsInspector {
         let exit_fn = obj.get("exit", &mut ctx)?.as_object().cloned().filter(|o| o.is_callable());
         let step_fn = obj.get("step", &mut ctx)?.as_object().cloned().filter(|o| o.is_callable());
 
-        let config =
+        let _js_config_value =
             JsValue::from_json(&config, &mut ctx).map_err(JsInspectorError::InvalidJsonConfig)?;
 
         if let Some(setup_fn) = obj.get("setup", &mut ctx)?.as_object() {
@@ -126,14 +143,16 @@ impl JsInspector {
 
             // call setup()
             setup_fn
-                .call(&(obj.clone().into()), &[config.clone()], &mut ctx)
+                .call(&(obj.clone().into()), &[_js_config_value.clone()], &mut ctx)
                 .map_err(JsInspectorError::SetupCallFailed)?;
         }
 
         Ok(Self {
             ctx,
-            _config: config,
+            _js_config_value,
+            config,
             obj,
+            transaction_context,
             result_fn,
             fault_fn,
             enter_fn,
@@ -145,6 +164,21 @@ impl JsInspector {
         })
     }
 
+    /// Returns the config object.
+    pub fn config(&self) -> &serde_json::Value {
+        &self.config
+    }
+
+    /// Returns the transaction context.
+    pub fn transaction_context(&self) -> &TransactionContext {
+        &self.transaction_context
+    }
+
+    /// Sets the transaction context.
+    pub fn set_transaction_context(&mut self, transaction_context: TransactionContext) {
+        self.transaction_context = transaction_context;
+    }
+
     /// Calls the result function and returns the result as [serde_json::Value].
     ///
     /// Note: This is supposed to be called after the inspection has finished.
@@ -199,11 +233,8 @@ impl JsInspector {
             block: env.block.number.try_into().unwrap_or(u64::MAX),
             output: output_bytes.unwrap_or_default(),
             time: env.block.timestamp.to_string(),
-            // TODO: fill in the following fields
             intrinsic_gas: 0,
-            block_hash: None,
-            tx_index: None,
-            tx_hash: None,
+            transaction_ctx: self.transaction_context.clone(),
         };
         let ctx = ctx.into_js_object(&mut self.ctx)?;
         let db = db.into_js_object(&mut self.ctx)?;
@@ -510,6 +541,44 @@ where
     }
 }
 
+/// Contains some contextual infos for a transaction execution that is made available to the JS
+/// object.
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub struct TransactionContext {
+    /// Hash of the block the tx is contained within.
+    ///
+    /// `None` if this is a call.
+    pub block_hash: Option<B256>,
+    /// Index of the transaction within a block.
+    ///
+    /// `None` if this is a call.
+    pub tx_index: Option<usize>,
+    /// Hash of the transaction being traced.
+    ///
+    /// `None` if this is a call.
+    pub tx_hash: Option<B256>,
+}
+
+impl TransactionContext {
+    /// Sets the block hash.
+    pub fn with_block_hash(mut self, block_hash: B256) -> Self {
+        self.block_hash = Some(block_hash);
+        self
+    }
+
+    /// Sets the index of the transaction within a block.
+    pub fn with_tx_index(mut self, tx_index: usize) -> Self {
+        self.tx_index = Some(tx_index);
+        self
+    }
+
+    /// Sets the hash of the transaction.
+    pub fn with_tx_hash(mut self, tx_hash: B256) -> Self {
+        self.tx_hash = Some(tx_hash);
+        self
+    }
+}
+
 /// Request variants to be sent from the inspector to the database
 #[derive(Debug, Clone)]
 pub enum JsDbRequest {