Fixed support for Node 8.12.0.

Author: mcollina

lib/v8-log-to-ticks.js

@@ -3,11 +3,32 @@
 const { spawn } = require('child_process')
 const { parse } = require('jsonstream2')
 const { extname } = require('path')
+const { promisify } = require('util')
 const through = require('through2')
 const fs = require('fs')
 const pump = require('pump')
 
-module.exports = v8LogToTicks
+const readFile = promisify(fs.readFile)
+const writeFile = promisify(fs.writeFile)
+
+module.exports = process
+
+function process (isolateLogPath, node) {
+  return filterLinesThatAreTooLong(isolateLogPath).then((filtered) => {
+    return v8LogToTicks(filtered, node)
+  })
+}
+
+// long lines make the --preprocess crash. We are just filtering them beforehand
+// as Node.js 8.12.0 would crash if there is any error in the preprocess script
+function filterLinesThatAreTooLong (isolateLogPath) {
+  const dest = isolateLogPath + '.filtered'
+  // TODO use streams
+  return readFile(isolateLogPath, 'utf8').then((data) => {
+    data = data.split('\n').filter((s) => s.length < 1024).join('\n')
+    return writeFile(dest, data)
+  }).then(() => dest)
+}
 
 function v8LogToTicks (isolateLogPath, node) {
   const isJson = extname(isolateLogPath) === '.json'
@@ -22,8 +43,12 @@ function v8LogToTicks (isolateLogPath, node) {
     // it's an error in the V8 internal tick profiler)
     // ignore them.
     const ignore = /unknown code state:/
+    // pump(sp.stderr, process.stderr)
     pump(sp.stderr, through((errMsg, _, cb) => {
-      if (ignore.test(errMsg)) cb()
+      if (ignore.test(errMsg)) {
+        console.log('ignored', errMsg.toString())
+        cb()
+      }
       else cb(errMsg, _, cb)
     }), process.stderr)
   }