funda-assignment
Funda Programming Assignment
Install
$ git clone https://github.com/pietgeursen/funda-assignment
$ cd funda-assignment
$ npm install
Rename the .env_example file to .env. Edit the file and set your funda api key.
Run
Find the agents with the most listings.
$ ./index
Will display something like:
[##########################################################################] 100%
╔════════════════════════════════════════════════╤════════════════════════════════════════════════════╗
║ Agent Name │ Number of Listings ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ ERA Van De Steege │ 37 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ Broersma Makelaardij │ 35 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ Hoekstra en van Eck Amsterdam West │ 27 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ Hoekstra en van Eck Amsterdam Noord │ 27 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ Makelaardij Van der Linden Amsterdam │ 24 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ Makelaarsland │ 20 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ RET Makelaars │ 18 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ Heeren Makelaars │ 18 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ Von Poll Real Estate │ 16 ║
╟────────────────────────────────────────────────┼────────────────────────────────────────────────────╢
║ Hallie & Van Klooster Makelaardij │ 15 ║
╚════════════════════════════════════════════════╧════════════════════════════════════════════════════╝
Find the agents with the most listings with gardens.
$ ./index -g
Print help message
$ ./index.js --help
Prints:
Usage:
index.js [OPTIONS] [ARGS]
Options:
-g, --withGardens BOOL Only properties that have gardens
-h, --help Display help and usage details
Test
$ npm test
> npx standard && tape test/*.test.js
TAP version 13
# end to end
ok 1 progress gets called
ok 2 error is null
ok 3 there are two agents
ok 4 The agent with the most objects is first
ok 5 The agent has the correct number of listings
# if the request fails, getTopTenAgents should call back with error
ok 6 should be equal
# if the request succeeds but has an empty body, getTopTenAgents should call back with error
ok 7 Error is set
# topTenAgents orders the results correctly
ok 8 agents are in correct order
# topTenAgents only gets the top ten
ok 9 selects only the top ten
# doesn't explode if passed an empty object
ok 10 should not throw
1..10
# tests 10
# pass 10
# ok
Add to the path (in development)
$ npm link
And then you can run this from anywhere with:
$ topTenFundaAgents -g
Features
- Rate limited
- Shows a progress bar
- Uses a .env file so that you don't accidentally commit the api key
- Program exits with a helpful message if you don't provide an api key
- Has at least some tests. The end to end test mocks the
requestlibrary so the tests don't rely on the network - Has a sane cli interface that would be easy to extend
- Tests enforce coding style (standard)
- CI is set up
- There is a separate
config.jsonwhere things like the rate limit can easily be changed - Supports being added to the path
Thoughts and discussion
This is not the nicest way to do this
I spent a bit of time trying to find the api docs. I was expecting to find some query parameters that did the sorting for me. I guess it's part of the exercise to see how we solve this problem. But in the real world you'd do this all on the backend (assuming you had control over the backend) and expose some query parameters on the api eg.
/makelaars/amsterdam?orderBy=NumListingsDescending
Rate limiting
There other ways the rate limiting could be done to improve performance. One way would be to track the number of requests so far this minute and only limit when you cross that threshold. This has the down side that if you re-run the script again you'll exceed the limit.
Pull streams vs other options
I like pull streams. They're like RxJs but a little more accessible. I love a functional approach and like solving these sorts of problems with combinations of map filter and reduce.
I also picked pull-streams because they're fun and a bit different. If I was writing this in a professional environment I'd probably use async / await. I think I could make a pretty tidy solution doing that. Or even just using RxJs.
Ramda
I had a go at using ramda in sortAndSelectTopAgents.js. I've only used it once or twice but it's a library that seems fun and I want to learn it better. Again, for production, maybe I'd use lodash because it's a bit more accessible. I think ramda's functional style is a bit mind bendy when you're learning it (at least for me.)