Class variable is undefined... despite being defined - coffeescript

Question

I have a class called RouteBinder that looks like this:
class RouteBinder
constructor: (#server, #pool) ->
bindRoute: (name, fn, method = "post", useDb = true) ->
#server[method]("/api/accounts/v1/" + name, (req, res, next) ->
client = await #pool.connect() if useDb?
await fn req, res, next, client
await #pool.release() if useDb?
)
I declare it and call it like this:
binder = new RouteBinder server, pool
binder.bindRoute "login", controllers.login
(Pool is node-postgres's Pool and is declared and tested earlier like this)
pool = new Pool
[...]
try
client = await pool.connect()
await client.query 'SELECT 1=1'
catch e
console.fatal "Could not connect to database: #{e}"
return
finally
try client.release() if client?
catch e
console.fatal "Couldn't release client: #{e}"
return
console.info 'Database is OK!'
When running this, I get this error:
02/14 18:44:34 error (node:11855) UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'connect' of undefined
at _callee2$ (/home/vi/[redacted]_accounts/main.js:136:38)
at tryCatch (/home/vi/[redacted]_accounts/node_modules/regenerator-runtime/runtime.js:45:40)
at Generator.invoke [as _invoke] (/home/vi/[redacted]_accounts/node_modules/regenerator-runtime/runtime.js:271:22)
at Generator.prototype.(anonymous function) [as next] (/home/vi/[redacted]_accounts/node_modules/regenerator-runtime/runtime.js:97:21)
at asyncGeneratorStep (/home/vi/[redacted]_accounts/node_modules/#babel/runtime/helpers/asyncToGenerator.js:3:24)
at _next (/home/vi/[redacted]_accounts/node_modules/#babel/runtime/helpers/asyncToGenerator.js:25:9)
at /home/vi/[redacted]_accounts/node_modules/#babel/runtime/helpers/asyncToGenerator.js:32:7
at new Promise (<anonymous>)
at /home/vi/[redacted]_accounts/node_modules/#babel/runtime/helpers/asyncToGenerator.js:21:12
at /home/vi/[redacted]_accounts/main.js:166:26
02/14 18:44:34 error (node:11855) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
02/14 18:44:34 error (node:11855) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
I'm using CoffeeScript compiled transpiled with Babel. My .babelrc looks like this:
{
"presets": ["#babel/env"],
"plugins": [
["#babel/plugin-transform-runtime",
{
"regenerator": true
}
]
]
}
Sorry if it's a rookie question, I'm still learning and would love all the advice I can get.

Answer 1

I figured out my mistake. Both #pool and #server were defined, however, the inline function (handler) for #server[method] was running in the context of that function.
The solution was to bind it to the RouteBinder instance using .bind(#) (or .bind(this), if you prefer)
bindRoute: (name, fn, method = "post", useDb = true) ->
#server[method]("/api/accounts/v1/" + name, ((req, res, next) ->
console.log "pool", #pool
client = await #pool.connect() if useDb?
await fn req, res, next, client
await #pool.release() if useDb?
).bind(#))