test: stdio pipe behavior tests

Add two regression tests for stdio over pipes.
test-stdio-pipe-access tests if accessing stdio pipe that is being read
by another process does not deadlocks Node.js. This was reported in
#10836 and was fixed in v8.3.0.
The deadlock would happen intermittently, so we run the test 5 times.
test-stdio-pipe-redirect tests if redirecting one child process stdin to
another process stdout does not crash Node as reported in
#17493. It was fixed in
#18019.
PR-URL: #18614
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: bzoz

test/parallel/test-stdio-pipe-access.js

@@ -0,0 +1,35 @@
+'use strict';
+require('../common');
+
+// Test if Node handles acessing process.stdin if it is a redirected
+// pipe without deadlocking
+const{ spawn, spawnSync }=require('child_process');
+
+constnumTries=5;
+constwho=process.argv.length<=2 ? 'runner' : process.argv[2];
+
+switch(who){
+case'runner':
+for(letnum=0;num<numTries;++num){
+spawnSync(process.argv0,
+[process.argv[1],'parent'],
+{'stdio': 'inherit'});
+}
+break;
+case'parent':
+constmiddle=spawn(process.argv0,
+[process.argv[1],'middle'],
+{'stdio': 'pipe'});
+middle.stdout.on('data',()=>{});
+break;
+case'middle':
+spawn(process.argv0,
+[process.argv[1],'bottom'],
+{'stdio': [process.stdin,
+process.stdout,
+process.stderr]});
+break;
+case'bottom':
+process.stdin;
+break;
+}

test/parallel/test-stdio-pipe-redirect.js

@@ -0,0 +1,38 @@
+'use strict';
+require('../common');
+
+// Test if Node handles redirecting one child process stdout to another
+// process stdin without crashing.
+constspawn=require('child_process').spawn;
+
+constwriteSize=100;
+consttotalDots=10000;
+
+constwho=process.argv.length<=2 ? 'parent' : process.argv[2];
+
+switch(who){
+case'parent':
+constconsumer=spawn(process.argv0,[process.argv[1],'consumer'],{
+stdio: ['pipe','ignore','inherit'],
+});
+constproducer=spawn(process.argv0,[process.argv[1],'producer'],{
+stdio: ['pipe',consumer.stdin,'inherit'],
+});
+process.stdin.on('data',()=>{});
+producer.on('exit',process.exit);
+break;
+case'producer':
+constbuffer=Buffer.alloc(writeSize,'.');
+letwritten=0;
+constwrite=()=>{
+if(written<totalDots){
+written+=writeSize;
+process.stdout.write(buffer,write);
+}
+};
+write();
+break;
+case'consumer':
+process.stdin.on('data',()=>{});
+break;
+}