promisified exec and execFile should return a promise with ChildProce…

…ss instance attached (#880)

prelude/bootstrap.js

@@ -1660,22 +1660,30 @@ function payloadFileSync(pointer) {
  // CHILD_PROCESS ///////////////////////////////////////////////
  // /////////////////////////////////////////////////////////////
 
- var customPromiseExecFunction = (o) => (...args) =>
- new Promise((resolve, reject) => {
- o.apply(
- undefined,
- args.concat((error, stdout, stderr) => {
- if (error !== null) {
- error.stdout = stdout;
- error.stderr = stderr;
- reject(error);
- } else {
- resolve({ stdout, stderr });
- }
- })
- );
+ var customPromiseExecFunction = (o) => (...args) => {
+ let resolve;
+ let reject;
+ const p = new Promise((res, rej) => {
+ resolve = res;
+ reject = rej;
  });
 
+ p.child = o.apply(
+ undefined,
+ args.concat((error, stdout, stderr) => {
+ if (error !== null) {
+ error.stdout = stdout;
+ error.stderr = stderr;
+ reject(error);
+ } else {
+ resolve({ stdout, stderr });
+ }
+ })
+ );
+
+ return p;
+ };
+
  Object.defineProperty(require('child_process').exec, custom, {
  value: customPromiseExecFunction(require('child_process').exec),
  });