inject resetAndDestroy into socket in test for older versions of node

Author: RythenGlyth

test/MockFtpServer.js

@@ -39,6 +39,15 @@ module.exports = class MockFtpServer {
         })
         this.dataConn = undefined
         this.dataServer = net.createServer(conn => {
+            if(!conn.resetAndDestroy) {
+                conn.resetAndDestroy = () => {
+                    conn._handle.reset(() => {
+                        this.conn.emit("close")
+                    })
+                    conn._handle.onread = () =>{};
+                    conn._handle = null;
+                }
+            }
             this.dataConn = conn
             this.connections.push(conn)
             this.didOpenDataConn()

test/downloadSpec.js

@@ -148,11 +148,17 @@ describe("Download to stream", function() {
         dataSocket.destroy(new Error("Error that should be ignored because task has completed successfully"))
     })
     it("handles early data socket closure", async () => {
+        /**
+         * type of this.client
+         * @type {Client}
+         */
+        this.client;
+
         this.server.addHandlers({
             "pasv": () => `227 Entering Passive Mode (${this.server.dataAddressForPasvResponse})`,
             "retr": ({arg})  => {
                 //close data connection such that client receives ECONNRESET
-                this.server.dataConn.resetAndDestroy?.()
+                this.server.dataConn.resetAndDestroy()
 
                 return `550 ${arg}: No such file or directory.`
             }