From 2774187857c4d23e61c01cbfa36c7f1338470f2b Mon Sep 17 00:00:00 2001
From: Tom Esterez <testerez@gmail.com>
Date: Mon, 27 Jan 2020 02:48:17 -0500
Subject: [PATCH] Return exit codes (#213)

---
 README.md                       |  2 +-
 src/completion-listener.js      | 48 ++++++++++++++++++---------------
 src/completion-listener.spec.js | 22 +++++++--------
 3 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/README.md b/README.md
index 4ed1f5bb..bbf2203a 100644
--- a/README.md
+++ b/README.md
@@ -247,7 +247,7 @@ concurrently can be used programmatically by using the API documented below:
     to use when prefixing with `time`. Default: `yyyy-MM-dd HH:mm:ss.ZZZ`
 
 > Returns: a `Promise` that resolves if the run was successful (according to `successCondition` option),
-> or rejects otherwise.
+> or rejects, containing an array with the exit codes of each command that has been run.
 
 Example:
 
diff --git a/src/completion-listener.js b/src/completion-listener.js
index d5439463..b4e735ac 100644
--- a/src/completion-listener.js
+++ b/src/completion-listener.js
@@ -7,29 +7,33 @@ module.exports = class CompletionListener {
         this.scheduler = scheduler;
     }
 
-    listen(commands) {
-        const closeStreams = commands.map(command => command.close);
-        const allClosed = Rx.zip(...closeStreams);
-        return Rx.merge(...closeStreams).pipe(
-            bufferCount(closeStreams.length),
-            map(exitCodes => {
-                switch (this.successCondition) {
-                /* eslint-disable indent */
-                    case 'first':
-                        return exitCodes[0] === 0;
+    isSuccess(exitCodes) {
+        switch (this.successCondition) {
+        /* eslint-disable indent */
+            case 'first':
+                return exitCodes[0] === 0;
+
+            case 'last':
+                return exitCodes[exitCodes.length - 1] === 0;
 
-                    case 'last':
-                        return exitCodes[exitCodes.length - 1] === 0;
+            default:
+                return exitCodes.every(exitCode => exitCode === 0);
+            /* eslint-enable indent */
+        }
+    }
 
-                    default:
-                        return exitCodes.every(exitCode => exitCode === 0);
-                /* eslint-enable indent */
-                }
-            }),
-            switchMap(success => success
-                ? Rx.of(null, this.scheduler)
-                : Rx.throwError(new Error(), this.scheduler)),
-            take(1)
-        ).toPromise();
+    listen(commands) {
+        const closeStreams = commands.map(command => command.close);
+        return Rx.merge(...closeStreams)
+            .pipe(
+                bufferCount(closeStreams.length),
+                switchMap(exitCodes =>
+                    this.isSuccess(exitCodes)
+                        ? Rx.of(exitCodes, this.scheduler)
+                        : Rx.throwError(exitCodes, this.scheduler)
+                ),
+                take(1)
+            )
+            .toPromise();
     }
 };
diff --git a/src/completion-listener.spec.js b/src/completion-listener.spec.js
index 9b371ef2..9c6bef32 100644
--- a/src/completion-listener.spec.js
+++ b/src/completion-listener.spec.js
@@ -9,10 +9,11 @@ beforeEach(() => {
     scheduler = new TestScheduler();
 });
 
-const createController = successCondition => new CompletionListener({
-    successCondition,
-    scheduler
-});
+const createController = successCondition =>
+    new CompletionListener({
+        successCondition,
+        scheduler
+    });
 
 describe('with default success condition set', () => {
     it('succeeds if all processes exited with code 0', () => {
@@ -23,7 +24,7 @@ describe('with default success condition set', () => {
 
         scheduler.flush();
 
-        return expect(result).resolves.toBeNull();
+        return expect(result).resolves.toEqual([0, 0]);
     });
 
     it('fails if one of the processes exited with non-0 code', () => {
@@ -34,11 +35,10 @@ describe('with default success condition set', () => {
 
         scheduler.flush();
 
-        expect(result).rejects.toThrowError();
+        expect(result).rejects.toEqual([0, 1]);
     });
 });
 
-
 describe('with success condition set to first', () => {
     it('succeeds if first process to exit has code 0', () => {
         const result = createController('first').listen(commands);
@@ -48,7 +48,7 @@ describe('with success condition set to first', () => {
 
         scheduler.flush();
 
-        return expect(result).resolves.toBeNull();
+        return expect(result).resolves.toEqual([0, 1]);
     });
 
     it('fails if first process to exit has non-0 code', () => {
@@ -59,7 +59,7 @@ describe('with success condition set to first', () => {
 
         scheduler.flush();
 
-        return expect(result).rejects.toThrowError();
+        return expect(result).rejects.toEqual([1, 0]);
     });
 });
 
@@ -72,7 +72,7 @@ describe('with success condition set to last', () => {
 
         scheduler.flush();
 
-        return expect(result).resolves.toBeNull();
+        return expect(result).resolves.toEqual([1, 0]);
     });
 
     it('fails if last process to exit has non-0 code', () => {
@@ -83,6 +83,6 @@ describe('with success condition set to last', () => {
 
         scheduler.flush();
 
-        return expect(result).rejects.toThrowError();
+        return expect(result).rejects.toEqual([0, 1]);
     });
 });