[DI] Add stack trace to log probe results

This stack trace represents the point in the execution when the
breakpoint associated with the probe was hit.

The strack frames also include a `columnNumber` property, even though
the API doesn't yet use this property. However, support for column
information in the backend is being added in parallel.

integration-tests/debugger/index.spec.js

@@ -308,6 +308,22 @@ describe('Dynamic Instrumentation', function () {
         assert.isTrue(payload['debugger.snapshot'].timestamp > Date.now() - 1000 * 60)
         assert.isTrue(payload['debugger.snapshot'].timestamp <= Date.now())
 
+        assert.isArray(payload['debugger.snapshot'].stack)
+        assert.isAbove(payload['debugger.snapshot'].stack.length, 0)
+        for (const frame of payload['debugger.snapshot'].stack) {
+          assert.isObject(frame)
+          assert.hasAllKeys(frame, ['fileName', 'function', 'lineNumber', 'columnNumber'])
+          assert.isString(frame.fileName)
+          assert.isString(frame.function)
+          assert.isAbove(frame.lineNumber, 0)
+          assert.isAbove(frame.columnNumber, 0)
+        }
+        const topFrame = payload['debugger.snapshot'].stack[0]
+        assert.match(topFrame.fileName, new RegExp(`${appFile}$`)) // path seems to be prefeixed with `/private` on Mac
+        assert.strictEqual(topFrame.function, 'handler')
+        assert.strictEqual(topFrame.lineNumber, probeLineNo)
+        assert.strictEqual(topFrame.columnNumber, 3)
+
         done()
       })
 

packages/dd-trace/src/debugger/devtools_client/index.js

@@ -4,6 +4,7 @@ const { randomUUID } = require('crypto')
 const { breakpoints } = require('./state')
 const session = require('./session')
 const send = require('./send')
+const { getScriptUrlFromId } = require('./state')
 const { ackEmitting } = require('./status')
 const { parentThreadId } = require('./config')
 const log = require('../../log')
@@ -35,6 +36,17 @@ session.on('Debugger.paused', async ({ params }) => {
     thread_name: threadName
   }
 
+  const stack = params.callFrames.map((frame) => {
+    let fileName = getScriptUrlFromId(frame.location.scriptId)
+    if (fileName.startsWith('file://')) fileName = fileName.substr(7) // TODO: This might not be required
+    return {
+      fileName,
+      function: frame.functionName,
+      lineNumber: frame.location.lineNumber + 1, // Beware! lineNumber is zero-indexed
+      columnNumber: frame.location.columnNumber + 1 // Beware! columnNumber is zero-indexed
+    }
+  })
+
   // TODO: Send multiple probes in one HTTP request as an array
   for (const probe of probes) {
     const snapshot = {
@@ -45,6 +57,7 @@ session.on('Debugger.paused', async ({ params }) => {
         version: probe.version,
         location: probe.location
       },
+      stack,
       language: 'javascript'
     }
 

packages/dd-trace/src/debugger/devtools_client/remote_config.js

@@ -1,7 +1,7 @@
 'use strict'
 
 const { workerData: { rcPort } } = require('node:worker_threads')
-const { getScript, probes, breakpoints } = require('./state')
+const { findScriptFromPartialPath, probes, breakpoints } = require('./state')
 const session = require('./session')
 const { ackReceived, ackInstalled, ackError } = require('./status')
 const log = require('../../log')
@@ -120,7 +120,7 @@ async function addBreakpoint (probe) {
   // TODO: Inbetween `await session.post('Debugger.enable')` and here, the scripts are parsed and cached.
   // Maybe there's a race condition here or maybe we're guraenteed that `await session.post('Debugger.enable')` will
   // not continue untill all scripts have been parsed?
-  const script = getScript(file)
+  const script = findScriptFromPartialPath(file)
   if (!script) throw new Error(`No loaded script found for ${file} (probe: ${probe.id}, version: ${probe.version})`)
   const [path, scriptId] = script
 

packages/dd-trace/src/debugger/devtools_client/state.js

@@ -2,7 +2,8 @@
 
 const session = require('./session')
 
-const scripts = []
+const scriptIds = []
+const scriptUrls = new Map()
 
 module.exports = {
   probes: new Map(),
@@ -25,10 +26,14 @@ module.exports = {
    * @param {string} path
    * @returns {[string, string] | undefined}
    */
-  getScript (path) {
-    return scripts
+  findScriptFromPartialPath (path) {
+    return scriptIds
       .filter(([url]) => url.endsWith(path))
       .sort(([a], [b]) => a.length - b.length)[0]
+  },
+
+  getScriptUrlFromId (id) {
+    return scriptUrls.get(id)
   }
 }
 
@@ -41,7 +46,8 @@ module.exports = {
 // - `` - Not sure what this is, but should just be ignored
 // TODO: Event fired for all files, every time debugger is enabled. So when we disable it, we need to reset the state
 session.on('Debugger.scriptParsed', ({ params }) => {
+  scriptUrls.set(params.scriptId, params.url)
   if (params.url.startsWith('file:')) {
-    scripts.push([params.url, params.scriptId])
+    scriptIds.push([params.url, params.scriptId])
   }
 })