Listen for Jest crashing, and restart the watcher

Environment

1. node -v: 8.4
2. Operating system: macOS

Steps to Reproduce

Run Jest for a very long time. Get output like:

[83639:0x103000000]  2640294 ms: Mark-sweep 1403.7 (1559.1) -> 1403.7 (1559.1) MB, 1658.3 / 0.0 ms  allocation failure GC in old space requested
[83639:0x103000000]  2642200 ms: Mark-sweep 1403.7 (1559.1) -> 1403.7 (1542.1) MB, 1905.3 / 0.0 ms  last resort 
[83639:0x103000000]  2644065 ms: Mark-sweep 1403.7 (1542.1) -> 1403.7 (1541.1) MB, 1863.2 / 0.0 ms  last resort
<--- JS stacktrace --->

==== JS stack trace =========================================

Security context: 0x3c40f489cef1 <JSObject>
    2: stringSlice(aka stringSlice) [buffer.js:556] [bytecode=0x247d9e747009 offset=96](this=0x3c40f4882241 <undefined>,buf=0x173c99209f01 <Uint8Array map = 0x358156c43de1>,encoding=0x3c40f48fe879 <String[4]: utf8>,start=0,end=298264)
    4: toString [buffer.js:629] [bytecode=0x247d9e746c41 offset=148](this=0x173c99209f01 <Uint8Array map = 0x358156c43de1>,encoding=0x3c40f48fe879 <String[4]: utf8...
FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory

 1: 
node::Abort() [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]
 2: 
node::FatalException(v8::Isolate*, v8::Local<v8::Value>, v8::Local<v8::Message>) [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]
 3: 
v8::internal::V8::FatalProcessOutOfMemory(char const*, bool)
 [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]
 4: 
v8::internal::Factory::NewRawTwoByteString(int, v8::internal::PretenureFlag) [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]
 5: 
v8::internal::Factory::NewStringFromUtf8(v8::internal::Vector<char const>, v8::internal::PretenureFlag)
 [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]
 6: 
v8::String::NewFromUtf8(v8::Isolate*, char const*, v8::NewStringType, int) [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]
 7: 
node::StringBytes::Encode(v8::Isolate*, char const*, unsigned long, node::encoding, v8::Local<v8::Value>*)
 [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]


 8: 
void node::Buffer::(anonymous namespace)::StringSlice<(node::encoding)1>(v8::FunctionCallbackInfo<v8::Value> const&)
 [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]
 9: 
v8::internal::FunctionCallbackArguments::Call(void (*)(v8::FunctionCallbackInfo<v8::Value> const&)) [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]

10: 
v8::internal::MaybeHandle<v8::internal::Object> v8::internal::(anonymous namespace)::HandleApiCallHelper<false>(v8::internal::Isolate*, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::FunctionTemplateInfo>, v8::internal::Handle<v8::internal::Object>, v8::internal::BuiltinArguments) [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]

11: 
v8::internal::Builtin_Impl_HandleApiCall(v8::internal::BuiltinArguments, v8::internal::Isolate*) [/Users/orta/.nvm/versions/node/v8.4.0/bin/node]

12: 0x23c1f6a840dd

Closed Jest
Closed Jest

Expected Behavior

Restart the watcher, and continue, show a message that Jest crashed and was re-booted so that people are not confused.

Actual Behavior

The spinner indicating it is working continues to spin.

[connectdotz]

there is one concern… if for some reason jest couldn’t be started, we will be firing it up continuously in that case… eventually killed vscode… maybe we should have a max restart count to safeguard this issue… thoughts?

[bookman25]

Related: #49