Refactor from.

lib/index.js

@@ -342,6 +342,23 @@ const Channel = function(length = 0) {
   );
 };
 
+// Node.js stream.readable
+const fromNodeStream = (channel, stream) => {
+  stream.on(`readable`, async () => {
+    for (;;) {
+      const data = stream.read();
+
+      if (data === null) {
+        break;
+      } else {
+        await channel.push(data);
+      }
+    }
+  });
+
+  stream.once(`end`, channel.close);
+};
+
 Channel.from = (values, mapfn, thisArg) => {
   const channel = Channel();
 
@@ -367,20 +384,7 @@ Channel.from = (values, mapfn, thisArg) => {
           }
         }
       } catch (exception) {
-        // Node.js stream.readable
+        fromNodeStream(channel, values);
-        values.on(`readable`, async () => {
-          while (true) {
-            const data = values.read();
-
-            if (data === null) {
-              break;
-            } else {
-              await channel.push(data);
-            }
-          }
-        });
-
-        values.once(`end`, channel.close);
       }
     }
   })();