From a2746f6e683ad28f61cc7edcf1d17f7b5d707ee0 Mon Sep 17 00:00:00 2001
From: David Braun <David@NodeGuy.com>
Date: Wed, 18 Oct 2017 10:37:07 -0400
Subject: [PATCH] Channel.select: Complain when given non-channel method
 promises.

---
 lib/index.js  | 38 +++++++++++++++++++++++---------------
 test/index.js |  6 ++++++
 2 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/lib/index.js b/lib/index.js
index 5bf5968..aa5664f 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -326,23 +326,31 @@ Channel.select = methodPromises =>
   Object.assign(
     new Promise((resolve, reject) => {
       methodPromises.forEach(async promise => {
-        promise.prethen(() => {
-          // We've been given a heads-up that this method will complete first so
-          // cancel the other method calls.
-          methodPromises.forEach(other => {
-            if (other !== promise) {
-              other.cancel();
-            }
-          });
-        });
-
         try {
-          await promise;
-        } catch (exception) {
-          reject(exception);
-        }
+          promise.prethen(() => {
+            // We've been given a heads-up that this method will complete first
+            // so cancel the other method calls.
+            methodPromises.forEach(other => {
+              if (other !== promise) {
+                other.cancel();
+              }
+            });
+          });
 
-        resolve(promise.channel);
+          try {
+            await promise;
+          } catch (exception) {
+            reject(exception);
+          }
+
+          resolve(promise.channel);
+        } catch (exception) {
+          reject(
+            new TypeError(
+              `Channel.select accepts only Channel method promises.`
+            )
+          );
+        }
       });
     }),
     {
diff --git a/test/index.js b/test/index.js
index be85c78..f3eb702 100644
--- a/test/index.js
+++ b/test/index.js
@@ -128,6 +128,12 @@ describe(`Channel`, function() {
       closed
     );
   });
+
+  it(`complains when given non-channel method promises`, function() {
+    assertRejects(async () => {
+      await Channel.select([Promise.resolve()]);
+    }, new TypeError(`Channel.select accepts only Channel method promises.`));
+  });
 });
 
 describe(`functional interface`, async function() {