feat: Js Tracer

[carneiro-cw]

PR Type

Enhancement

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Description

• Implemented JS Tracer for EVM execution

• Added support for custom JavaScript tracing

• Integrated JsInspector in EVM execution flow

• Added E2E tests for JS tracing functionality

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Diagram Walkthrough

flowchart LR
  A["EVM Execution"] --> B["JsInspector"]
  B --> C["Custom JS Tracer"]
  C --> D["Trace Results"]
  E["E2E Tests"] --> F["Verify JS Tracing"]

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File Walkthrough

	Relevant files
Enhancement	evm.rs Integrate JsInspector into EVM execution flow                        src/eth/executor/evm.rs Imported JsInspector from revm_inspectors Implemented JsTracer case in GethDebugTracerType Added logic to execute JsInspector and return results +10/-1
Tests	e2e-json-rpc.test.ts Add E2E tests for JavaScript tracing functionality              e2e/test/external/e2e-json-rpc.test.ts Added test for simple JS tracer counting opcodes Implemented test for JS tracer capturing LOG opcodes Verified correct execution and result format of JS tracers +100/-0
Dependencies	Cargo.toml Enable JS tracer feature in revm-inspectors                            Cargo.toml Added "js-tracer" feature to revm-inspectors dependency +1/-1

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[github-actions]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

⏱️ Estimated effort to review: 4 🔵🔵🔵🔵⚪

🧪 PR contains tests

🔒 No security concerns identified

⚡ Recommended focus areas for review Error Handling The error handling in the JsTracer implementation might need improvement. Consider using a custom error type instead of converting errors to strings. let mut inspector = JsInspector::new(code, opts.tracer_config.into_json()).map_err(|e| anyhow!(e.to_string()))?; let mut evm_with_inspector = evm.with_inspector(&mut inspector); evm_with_inspector.fill_env(inspect_input); let tx = std::mem::take(&mut evm_with_inspector.tx); let block = std::mem::take(&mut evm_with_inspector.block); let res = evm_with_inspector.inspect_tx(tx.clone())?; GethTrace::JS(inspector.json_result(res, &tx, &block, &cache_db).map_err(|e| anyhow!(e.to_string()))?) Test Timeout The test "JS tracer for LOG opcodes" has an increased timeout. Consider optimizing the test or investigating why it needs such a long timeout. it("JS tracer for LOG opcodes", async function () { this.timeout(120000); // Increase timeout to 2 minutes

[github-actions]

PR Code Suggestions ✨

Explore these optional code suggestions:

Category	Suggestion	Impact
General	Improve error handling for JS tracer Consider handling potential errors more gracefully in the JS tracer implementation. Instead of using map_err to convert errors to strings, create custom error types for better error handling and reporting. src/eth/executor/evm.rs [326-332] -let mut inspector = JsInspector::new(code, opts.tracer_config.into_json()).map_err(|e| anyhow!(e.to_string()))?; +let mut inspector = JsInspector::new(code, opts.tracer_config.into_json()).map_err(|e| EvmError::JsTracerInitError(e))?; let mut evm_with_inspector = evm.with_inspector(&mut inspector); evm_with_inspector.fill_env(inspect_input); let tx = std::mem::take(&mut evm_with_inspector.tx); let block = std::mem::take(&mut evm_with_inspector.block); let res = evm_with_inspector.inspect_tx(tx.clone())?; -GethTrace::JS(inspector.json_result(res, &tx, &block, &cache_db).map_err(|e| anyhow!(e.to_string()))?) +GethTrace::JS(inspector.json_result(res, &tx, &block, &cache_db).map_err(|e| EvmError::JsTracerResultError(e))?) Suggestion importance[1-10]: 6 __ Why: The suggestion improves error handling by introducing custom error types (EvmError::JsTracerInitError and EvmError::JsTracerResultError) instead of converting errors to strings. This enhances error reporting and makes debugging easier, but it's not a critical change.	Low
	Optimize JS tracer for performance The JS tracer for LOG opcodes could be optimized for performance. Consider using bitwise operations instead of arithmetic for opcode checks and use a more efficient method for address conversion. e2e/test/external/e2e-json-rpc.test.ts [629-662] const logTracer = `{ logs: [], step: function(log, db) { const opcode = log.op.toNumber(); - // LOG0 = 0xa0, LOG1 = 0xa1, LOG2 = 0xa2, LOG3 = 0xa3, LOG4 = 0xa4 - if (opcode >= 0xa0 && opcode <= 0xa4) { - const topicCount = opcode - 0xa0; + if ((opcode & 0xf0) === 0xa0) { + const topicCount = opcode & 0x0f; const offset = log.stack.peek(0); const size = log.stack.peek(1); const topics = []; for (let i = 0; i < topicCount; i++) { topics.push(log.stack.peek(2 + i).toString(16)); } - // Convert address object to hex string - const addrObj = log.contract.getAddress(); - let address = '0x'; - for (let i = 0; i < 20; i++) { - const byte = addrObj[i.toString()]; - address += byte.toString(16).padStart(2, '0'); - } + const address = '0x' + log.contract.getAddress().toString('hex'); this.logs.push({ address: address, topics: topics, topicCount: topicCount, dataSize: size.toString() }); } }, fault: function(log, db) {}, result: function(ctx, db) { return this.logs } }`; Suggestion importance[1-10]: 5 __ Why: The suggestion optimizes the JS tracer by using bitwise operations and a more efficient address conversion method. While this improves performance, the impact is moderate as it's in a test file and not in the core functionality.	Low

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.67%. Comparing base (8d4605c) to head (ce65927).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2305      +/-   ##
==========================================
+ Coverage   77.36%   84.67%   +7.30%     
==========================================
  Files         130      130              
  Lines        9465    10800    +1335     
==========================================
+ Hits         7323     9145    +1822     
+ Misses       2142     1655     -487     

Flag	Coverage Δ
contracts-rocks-	44.22% <0.00%> (-0.06%)	⬇️
e2e-admin-password	22.02% <0.00%> (-0.02%)	⬇️
e2e-clock-stratus	24.79% <0.00%> (-0.02%)	⬇️
e2e-genesis	26.28% <0.00%> (-0.02%)	⬇️
e2e-importer-offline	58.40% <0.00%> (-0.08%)	⬇️
e2e-rpc-downloader	53.58% <0.00%> (-0.04%)	⬇️
e2e-stratus	55.81% <100.00%> (+0.02%)	⬆️
leader-follower-	61.39% <0.00%> (-0.05%)	⬇️
rust-tests	31.69% <0.00%> (?)

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[stratus-benchmark]

Final benchmark:
Run ID: bench-790ada61

Git Info:

• Branch: main
• Commit: d71b5f4
• PR: feat: Js Tracer #2305

Leader Stats:
RPS Stats: Max: 3555.00, Min: 1829.00, Avg: 2974.56, StdDev: 192.26
TPS Stats: Max: 3305.00, Min: 1456.00, Avg: 2971.41, StdDev: 198.38

Follower Stats:
Imported Blocks/s: Max: 17.00, Min: 4.00, Avg: 10.45, StdDev: 2.55
Imported Transactions/s: Max: 30526.00, Min: 6593.00, Avg: 24512.29, StdDev: 4061.27

Plots:

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