issue with nodemon

[kenenisa]

Nodemon works perfectly but when I include const LocalSession = require('telegraf-session-local') it keeps failing to restart like: [nodemon] restarting due to changes... [nodemon] starting 'node index.js' again and again.

I'm using nodemon 2.0.15 and the latest telegraf-session-local version

[TemaSM]

Hi @kenenisa

That's an expected behavior of nodemon, because it starts watching changes of files: [nodemon] watching extensions: js,mjs,json.
If you look into simple example:

telegraf-session-local/examples/simple.js

Line 6 in 43ab64d

bot.use((new LocalSession({ database: 'example_db.json' })).middleware())

- Here is database option which defines the path for database file of sessions, for example example_db.json.
telegraf-sessin-local uses underlying library called lowdb to store and manipulate database data.
When you start your bot, lowdb creates new file descriptor for database-file and touches it (look onto file modification date-time just after starting nodemon or node), which simply fires nodemon event like 'file was modified' and nodemon performing restart of your js file, which leads to looped behavior:
--(1)-- Start js file and watch for changes by nodemon --(2)--> JS file started by node --(3)--> Bot started and touched database file --(4)--> Nodemon detected change of json file --(5)--> Nodemon re-executes js file --> (1)

To fix this, please add config for nodemon to ignore json-database file, for example by adding new block into your package.json:

"nodemonConfig": {
  "ignore": ["sessions.json", "example_db.json"]
}

sessions.json - default filename of sessions' database in telegraf-session-local:

telegraf-session-local/lib/session.js

Line 15 in 43ab64d

* @param {String} [options.database] - Name or path to database file `default:` `'sessions.json'`

[kenenisa]

Hi @kenenisa

That's an expected behavior of nodemon, because it starts watching changes of files: [nodemon] watching extensions: js,mjs,json. If you look into simple example:

telegraf-session-local/examples/simple.js

Line 6 in 43ab64d

bot.use((new LocalSession({ database: 'example_db.json' })).middleware())

• Here is database option which defines the path for database file of sessions, for example example_db.json.
  telegraf-sessin-local uses underlying library called lowdb to store and manipulate database data.
  When you start your bot, lowdb creates new file descriptor for database-file and touches it (look onto file modification date-time just after starting nodemon or node), which simply fires nodemon event like 'file was modified' and nodemon performing restart of your js file, which leads to looped behavior:
  --(1)-- Start js file and watch for changes by nodemon --(2)--> JS file started by node --(3)--> Bot started and touched database file --(4)--> Nodemon detected change of json file --(5)--> Nodemon re-executes js file --> (1)
  To fix this, please add config for nodemon to ignore json-database file, for example by adding new block into your package.json:

{
  "...": "... other standard package.json values",
  "nodemonConfig": {
    "ignore": ["sessions.json", "example_db.json"]
  }
}

sessions.json - default filename of sessions' database in telegraf-session-local:

telegraf-session-local/lib/session.js

Line 15 in 43ab64d

* @param {String} [options.database] - Name or path to database file `default:` `'sessions.json'`

The issue is resolved. It's now working as intended.