stream: give error message if write() cb called twice

Otherwise, this condition would result in an error that just reads
`cb is not a function`, and which additionally could have lost
stack trace context through a `process.nextTick()` call.

PR-URL: nodejs#19510
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

lib/_stream_writable.js

@@ -37,6 +37,7 @@ const { getHighWaterMark } = require('internal/streams/state');
 const {
   ERR_INVALID_ARG_TYPE,
   ERR_METHOD_NOT_IMPLEMENTED,
+  ERR_MULTIPLE_CALLBACK,
   ERR_STREAM_CANNOT_PIPE,
   ERR_STREAM_DESTROYED,
   ERR_STREAM_NULL_VALUES,
@@ -449,6 +450,9 @@ function onwrite(stream, er) {
   var sync = state.sync;
   var cb = state.writecb;
 
+  if (typeof cb !== 'function')
+    throw new ERR_MULTIPLE_CALLBACK();
+
   onwriteStateUpdate(state);
 
   if (er)

test/parallel/test-stream-writable-write-cb-twice.js

@@ -0,0 +1,49 @@
+'use strict';
+const common = require('../common');
+const { Writable } = require('stream');
+
+{
+  // Sync + Sync
+  const writable = new Writable({
+    write: common.mustCall((buf, enc, cb) => {
+      cb();
+      common.expectsError(cb, {
+        code: 'ERR_MULTIPLE_CALLBACK',
+        type: Error
+      });
+    })
+  });
+  writable.write('hi');
+}
+
+{
+  // Sync + Async
+  const writable = new Writable({
+    write: common.mustCall((buf, enc, cb) => {
+      cb();
+      process.nextTick(() => {
+        common.expectsError(cb, {
+          code: 'ERR_MULTIPLE_CALLBACK',
+          type: Error
+        });
+      });
+    })
+  });
+  writable.write('hi');
+}
+
+{
+  // Async + Async
+  const writable = new Writable({
+    write: common.mustCall((buf, enc, cb) => {
+      process.nextTick(cb);
+      process.nextTick(() => {
+        common.expectsError(cb, {
+          code: 'ERR_MULTIPLE_CALLBACK',
+          type: Error
+        });
+      });
+    })
+  });
+  writable.write('hi');
+}