After upgrading to Expo SDK 36, expo-cli crashes with "TypeError: chunk.msg.match is not a function"

[kevgrig]

Description

After upgrading to Expo SDK 36, I'm always getting the following error immediately after launching in my emulator. I never received it before. Issue #519 is similar but expo start --clear didn't help.

Observed Behavior

/@expo/[email protected]/src/logs/PackagerLogsStream.ts:493
    if (chunk.msg.match(/\(node:.\d*\)/)) {
                  ^
TypeError: chunk.msg.match is not a function
    at PackagerLogsStream.chunk [as _cleanUpNodeErrors] (/@expo/[email protected]/src/logs/PackagerLogsStream.ts:493:19)
    at Object.write (/@expo/[email protected]/src/logs/PackagerLogsStream.ts:211:24)
    at Logger._emit (/usr/lib/node_modules/expo-cli/node_modules/@expo/bunyan/lib/bunyan.js:928:22)
    at Logger.info (/usr/lib/node_modules/expo-cli/node_modules/@expo/bunyan/lib/bunyan.js:1053:24)
    at Object.logInfo (/@expo/[email protected]/src/project/ProjectUtils.ts:92:27)
    at _logPackagerOutput (/@expo/[email protected]/src/Project.ts:1573:18)
    at Stream.packagerProcess.stdout.pipe.on.data (/@expo/[email protected]/src/Project.ts:1797:7)
    at Stream.emit (events.js:198:13)
    at drain (/usr/lib/node_modules/expo-cli/node_modules/through/index.js:36:16)
    at Stream.stream.queue.stream.push (/usr/lib/node_modules/expo-cli/node_modules/through/index.js:45:5)

Environment

$ expo diagnostics

  Expo CLI 3.11.1 environment info:
    System:
      OS: Linux 5.3 Fedora 30 (Workstation Edition) 30 (Workstation Edition)
      Shell: 5.0.7 - /bin/bash
    Binaries:
      Node: 10.16.3 - /usr/bin/node
      Yarn: 1.19.2 - /usr/bin/yarn
      npm: 6.9.0 - /usr/bin/npm
    npmPackages:
      expo: ^36.0.0 => 36.0.0 
      react: 16.9.0 => 16.9.0 
      react-native: https://github.com/expo/react-native/archive/sdk-36.0.0.tar.gz => 0.61.4 
      react-navigation: ^3.13.0 => 3.13.0 
    npmGlobalPackages:
      expo-cli: 3.11.1

• Phone/emulator/simulator platform, model and version: Android Emulator, Pixel 3a API 28

Reproducible Demo

I will try to work on this but the current code is private.

[kevgrig]

I'm exploring the source code and while I'm not sure how to modify the frames that are at /@expo/[...], I found in the third frame from the top (/usr/lib/node_modules/expo-cli/node_modules/@expo/bunyan/lib/bunyan.js) that there is the following line which I commented out:

//var xxx = function xxx() {};  // comment out to turn on debug logging

However, the log entries leading up to the failure just seem like they're logging some application JSON data and nothing particularly special:

XXX: writing log rec "          33" to "raw" stream (30 <= 30): {"name":"expo","hostname":"x270","pid":8503,"type":"project","project":"[...]","level":30,"tag":"metro","msg":"          33","time":"2019-12-16T06:07:01.496Z","id":"46815f80-1fca-11ea-a91c-2d452ab10d3b","v":0}

/@expo/[email protected]/src/logs/PackagerLogsStream.ts:493
    if (chunk.msg.match(/\(node:.\d*\)/)) {
                  ^
TypeError: chunk.msg.match is not a function
[...]

[kevgrig]

Looking at PackagerLogsStream.ts:211, a few lines after the failing call, there is a check for typeof chunk.msg === 'string', whereas the failing function (PackagerLogsStream.ts:488) seems to presume that if the chunk isn't of type object, then it must be a string. So, I'm just guessing, but perhaps the fix is:

$ git diff
diff --git a/packages/xdl/src/logs/PackagerLogsStream.ts b/packages/xdl/src/logs/PackagerLogsStream.ts
index 1df4d132..729f1f1a 100644
--- a/packages/xdl/src/logs/PackagerLogsStream.ts
+++ b/packages/xdl/src/logs/PackagerLogsStream.ts
@@ -490,7 +490,7 @@ export default class PackagerLogsStream {
       return chunk;
     }
 
-    if (chunk.msg.match(/\(node:.\d*\)/)) {
+    if (typeof chunk.msg === 'string' && chunk.msg.match(/\(node:.\d*\)/)) {
       // Example: (node:13817) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): SyntaxError: SyntaxError /Users/brent/universe/apps/new-project-template/main.js: Unexpected token (10:6)
       // The first part of this is totally useless, so let's remove it.
       if (chunk.msg.match(/UnhandledPromiseRejectionWarning/)) {

So I think the basic question is: how do we build a debug version of the /@expo/xdl code? I'm using a managed workflow.

[kevgrig]

Resolved after upgrading expo-cli to 3.11.2 and starting with expo start -c.