SFTP service is not triggered on file changes

[chathurace]

Description

No response

Steps to Reproduce

Write an SFTP service to listen to a folder (e.g. shown below).
Add a file to the SFTP server's corresponding folder.
onFileChange method in the service is not invoked.

Service:

import ballerina/ftp;
import ballerina/log;

listener ftp:Listener inventoryUpdatesL = new (protocol = ftp:SFTP, path = "/upload", port = 2222, auth = {
credentials: {
username: "foo",
password: "pass"
}
}, host = "localhost", pollingInterval = 3);

service ftp:Service on inventoryUpdatesL {
remote function onFileChange(ftp:WatchEvent & readonly event, ftp:Caller caller) returns error? {
do {
log:printInfo("Files changed.");
} on fail error err {
return error("unhandled error", err);
}
}
}

Version

1.0.5

Environment Details (with versions)

No response

[chathurace]

This issue occurs due to the missing fileNamePattern attribute in the service config. When it is added, service is triggered correctly (see below). However, this behavior should be improved by making the service trigger for all file types if a name pattern is not given.

listener ftp:Listener inventoryUpdatesL = new (protocol = ftp:SFTP, path = "/upload", port = 2222, auth = {
    credentials: {
        username: "foo",
        password: "pass"
    }
}, fileNamePattern = "(.*).csv", host = "localhost", pollingInterval = 3);

[LakshanWeerasinghe]

@niveathika can you check this?