[test visibility] Simple dynamic instrumentation - test visibility client

packages/dd-trace/src/ci-visibility/dynamic-instrumentation/index.js

@@ -0,0 +1,61 @@
+'use strict'
+
+const { join } = require('path')
+const { Worker } = require('worker_threads')
+const { randomUUID } = require('crypto')
+const log = require('../log')
+
+const probeIdToResolvePromise = new Map()
+
+class TestVisDynamicInstrumentation {
+  constructor () {
+    this.worker = null
+  }
+
+  // Return the snapshot id and a promise that's resolved if the breakpoint is hit
+  addLineProbe ({ file, line }) {
+    const snapshotId = randomUUID()
+
+    return [
+      snapshotId,
+      new Promise(resolve => {
+        const probeId = randomUUID()
+        probeIdToResolvePromise.set(probeId, resolve)
+        this.worker.postMessage({
+          snapshotId,
+          probe: { id: probeId, file, line }
+        })
+      })
+    ]
+  }
+
+  start () {
+    if (this.worker) return
+
+    const { NODE_OPTIONS, ...envWithoutNodeOptions } = process.env
+
+    log.debug('Starting Test Visibility - Dynamic Instrumentation client...')
+
+    this.worker = new Worker(
+      join(__dirname, 'worker', 'index.js'),
+      {
+        execArgv: [],
+        env: envWithoutNodeOptions
+      }
+    )
+
+    // Allow the parent to exit even if the worker is still running
+    this.worker.unref()
+
+    this.worker.on('message', ({ snapshot }) => {
+      const { probe: { id: probeId } } = snapshot
+      const resolve = probeIdToResolvePromise.get(probeId)
+      if (resolve) {
+        resolve({ snapshot })
+        probeIdToResolvePromise.delete(probeId)
+      }
+    }).unref() // We also need to unref this message handler
+  }
+}
+
+module.exports = new TestVisDynamicInstrumentation()

packages/dd-trace/src/ci-visibility/dynamic-instrumentation/worker/index.js

@@ -0,0 +1,86 @@
+const { parentPort } = require('worker_threads')
+// TODO: move session to common place
+const session = require('../../../debugger/devtools_client/session')
+// TODO: move getLocalStateForCallFrame to common place
+const { getLocalStateForCallFrame } = require('../../../debugger/devtools_client/snapshot')
+// TODO: move findScriptFromPartialPath to common place
+const {
+  findScriptFromPartialPath,
+  getStackFromCallFrames
+} = require('../../../debugger/devtools_client/state')
+const log = require('../../log')
+
+let sessionStarted = false
+
+const breakpointIdToSnapshotId = new Map()
+const breakpointIdToProbe = new Map()
+
+session.on('Debugger.paused', async ({ params: { hitBreakpoints: [hitBreakpoint], callFrames } }) => {
+  const probe = breakpointIdToProbe.get(hitBreakpoint)
+  if (!probe) {
+    return session.post('Debugger.resume')
+  }
+
+  const stack = getStackFromCallFrames(callFrames)
+
+  const getLocalState = await getLocalStateForCallFrame(callFrames[0])
+
+  await session.post('Debugger.resume')
+
+  const snapshotId = breakpointIdToSnapshotId.get(hitBreakpoint)
+
+  const snapshot = {
+    id: snapshotId,
+    timestamp: Date.now(),
+    probe: {
+      id: probe.probeId,
+      version: '0',
+      location: probe.location
+    },
+    stack,
+    language: 'javascript'
+  }
+
+  const state = getLocalState()
+  if (state) {
+    snapshot.captures = {
+      lines: { [probe.location.lines[0]]: { locals: state } }
+    }
+  }
+
+  parentPort.postMessage({ snapshot })
+})
+
+// TODO: add option to remove breakpoint
+parentPort.on('message', async ({ snapshotId, probe: { id: probeId, file, line } }) => {
+  await addBreakpoint(snapshotId, { probeId, file, line })
+})
+
+async function addBreakpoint (snapshotId, probe) {
+  if (!sessionStarted) await start()
+  const { file, line } = probe
+
+  probe.location = { file, lines: [String(line)] }
+
+  const script = findScriptFromPartialPath(file)
+  if (!script) throw new Error(`No loaded script found for ${file}`)
+
+  const [path, scriptId] = script
+
+  log.debug(`Adding breakpoint at ${path}:${line}`)
+
+  const { breakpointId } = await session.post('Debugger.setBreakpoint', {
+    location: {
+      scriptId,
+      lineNumber: line - 1
+    }
+  })
+
+  breakpointIdToProbe.set(breakpointId, probe)
+  breakpointIdToSnapshotId.set(breakpointId, snapshotId)
+}
+
+function start () {
+  sessionStarted = true
+  return session.post('Debugger.enable') // return instead of await to reduce number of promises created
+}

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

@@ -5,7 +5,7 @@ const { breakpoints } = require('./state')
 const session = require('./session')
 const { getLocalStateForCallFrame } = require('./snapshot')
 const send = require('./send')
-const { getScriptUrlFromId } = require('./state')
+const { getStackFromCallFrames } = require('./state')
 const { ackEmitting, ackError } = require('./status')
 const { parentThreadId } = require('./config')
 const log = require('../../log')
@@ -66,16 +66,7 @@ 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
-    }
-  })
+  const stack = getStackFromCallFrames(params.callFrames)
 
   // TODO: Send multiple probes in one HTTP request as an array (DEBUG-2848)
   for (const probe of probes) {

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

@@ -32,8 +32,17 @@ module.exports = {
       .sort(([a], [b]) => a.length - b.length)[0]
   },
 
-  getScriptUrlFromId (id) {
-    return scriptUrls.get(id)
+  getStackFromCallFrames (callFrames) {
+    return callFrames.map((frame) => {
+      let fileName = scriptUrls.get(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
+      }
+    })
   }
 }