test: cover thrown errors from exec() kill

This commit adds code coverage for the scenario where exec() kills a child process, but the call to ChildProcess#kill() throws an exception. PR-URL: #11038 Reviewed-By: Sam Roberts <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Franziska Hinkelmann <[email protected]>

Author: cjihrig

test/parallel/test-child-process-exec-kill-throws.js

@@ -0,0 +1,29 @@
+'use strict';
+// Flags: --expose_internals
+constcommon=require('../common');
+constassert=require('assert');
+constcp=require('child_process');
+constinternalCp=require('internal/child_process');
+
+if(process.argv[2]==='child'){
+// Keep the process alive and printing to stdout.
+setInterval(()=>{console.log('foo');},1);
+}else{
+// Monkey patch ChildProcess#kill() to kill the process and then throw.
+constkill=internalCp.ChildProcess.prototype.kill;
+
+internalCp.ChildProcess.prototype.kill=function(){
+kill.apply(this,arguments);
+thrownewError('mock error');
+};
+
+constcmd=`${process.execPath}${__filename} child`;
+constoptions={maxBuffer: 0};
+constchild=cp.exec(cmd,options,common.mustCall((err,stdout,stderr)=>{
+// Verify that if ChildProcess#kill() throws, the error is reported.
+assert(/^Error:mockerror$/.test(err));
+assert.strictEqual(stdout,'');
+assert.strictEqual(stderr,'');
+assert.strictEqual(child.killed,true);
+}));
+}