flaky: test-child-process-pipe-dataflow

[refack]

Job: https://ci.nodejs.org/job/node-test-binary-windows/23616/COMPILED_BY=vs2017,RUNNER=win10,RUN_SUBSET=3/testReport/junit/(root)/test/parallel_test_child_process_pipe_dataflow/
Worker: https://ci.nodejs.org/computer/test-azure_msft-win10-x64-3/
Code:
https://github.com/gireeshpunathil/node/blob/b1f82e4342f8a630b1ef83cd33781a725428f569/test/parallel/test-child-process-pipe-dataflow.js#L44-L46
Message:

assert.js:86
  throw new AssertionError(obj);
  ^

AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:

1 !== 0

    at ChildProcess.<anonymous> (c:\workspace\node-test-binary-windows\test\parallel\test-child-process-pipe-dataflow.js:45:12)
    at ChildProcess.<anonymous> (c:\workspace\node-test-binary-windows\test\common\index.js:367:15)
    at ChildProcess.emit (events.js:197:13)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:254:12)

[gireeshpunathil]

if grep found less bytes than expected, that should result in another assertion.
if grep did not find any bytes, then it should hang (our pipe is fused into its stdin) leading to timeout
if grep shows up exit code 1 would mean strange: Is it that grep is not available on the system? in which case the failure should be consistent!

Is this system picked part of regular CI? @refack - can you please check if it has grep in the first place? My test semantics expects UNIX simulated grep, not the windows native one (though I am not sure how different they are in terms of arguments). thanks!

[gireeshpunathil]

ran a 3K times on the failing system but no reproduce.

It turns out that the assumptions about grep were not right - it works like in any other system, and there is nothing special. At the moment the best thing I believe is to catch the standard error streams of the child process as well, so that we know what happened to those.

[Trott]

https://ci.nodejs.org/job/node-test-binary-windows/24562/COMPILED_BY=vs2017,RUNNER=win10,RUN_SUBSET=0/console

test-azure_msft-win10-x64-4

00:22:57 not ok 61 parallel/test-child-process-pipe-dataflow
00:22:57   ---
00:22:57   duration_ms: 0.175
00:22:57   severity: fail
00:22:57   exitcode: 1
00:22:57   stack: |-
00:22:57     got unexpected data from child #0:
00:22:57     cat
00:22:57     got unexpected data from child #0:
00:22:57     :
00:22:57     got unexpected data from child #0:
00:22:57      
00:22:57     got unexpected data from child #0:
00:22:57     write error
00:22:57     got unexpected data from child #0:
00:22:57     : 
00:22:57     got unexpected data from child #0:
00:22:57     No space left on device
00:22:57     got unexpected data from child #0:
00:22:57     
00:22:57     
00:22:57     assert.js:85
00:22:57       throw new AssertionError(obj);
00:22:57       ^
00:22:57     
00:22:57     AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:
00:22:57     
00:22:57     1 !== 0
00:22:57     
00:22:57         at ChildProcess.<anonymous> (c:\workspace\node-test-binary-windows\test\parallel\test-child-process-pipe-dataflow.js:42:14)
00:22:57         at ChildProcess.<anonymous> (c:\workspace\node-test-binary-windows\test\common\index.js:358:15)
00:22:57         at ChildProcess.emit (events.js:198:13)
00:22:57         at Process.ChildProcess._handle.onexit (internal/child_process.js:254:12)
00:22:57   ...

[refack]

No space left on device

Is this expected?

node/test/parallel/test-child-process-pipe-dataflow.js

Lines 36 to 44 in 269103a

	[cat, grep, wc].forEach((child, index) => {
	child.stderr.on('data', (d) => {
	// Don't want to assert here, as we might miss error code info.
	console.error(`got unexpected data from child #${index}:\n${d}`);
	});
	child.on('exit', common.mustCall(function(code) {
	assert.strictEqual(code, 0);
	}));
	});

P.S. Worker had 60GB free disk space.

[refack]

P.S. I want to add a lint rule that looks for asserts with no message in loops 🤔

[Trott]

https://ci.nodejs.org/job/node-test-binary-windows/24683/COMPILED_BY=vs2017,RUNNER=win10,RUN_SUBSET=1/console

test-azure_msft-win10-x64-5

10:32:10 not ok 62 parallel/test-child-process-pipe-dataflow
10:32:10   ---
10:32:10   duration_ms: 0.212
10:32:10   severity: fail
10:32:10   exitcode: 1
10:32:10   stack: |-
10:32:10     assert.js:85
10:32:10       throw new AssertionError(obj);
10:32:10       ^
10:32:10     
10:32:10     AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:
10:32:10     
10:32:10     1 !== 0
10:32:10     
10:32:10         at ChildProcess.<anonymous> (c:\workspace\node-test-binary-windows\test\parallel\test-child-process-pipe-dataflow.js:42:14)
10:32:10         at ChildProcess.<anonymous> (c:\workspace\node-test-binary-windows\test\common\index.js:358:15)
10:32:10         at ChildProcess.emit (events.js:198:13)
10:32:10         at Process.ChildProcess._handle.onexit (internal/child_process.js:254:12)
10:32:10   ...