sri-rang/securities-case

Not Actively Maintained - This was the interview project that got me a job at ING

Securities-Case

Build this project by;

$ mvn clean install

Main subprojects

securities-case-service

securities-case-services implements the services for this application and contains its domain model. The domain model is simple. There are is an Instrument class and a Price class. An instrument has a code and price. A price has a timestamp and an amount. The services module contains the InstrumentService (spring component) which can be used to retrieve all instruments with their latest prices. It is also possible to register a InstrumentListener which will callback in case a price of an instrument is updated. To simulate real instrument price updates a spring scheduler is used which randomly updates prices every second and triggers the callback.

securities-case-web

securities-case-web implements a REST API to retrieve the instrument list '/instruments' and contains a websocket to retrieve updates of instrument prices.

---

and now for the actual implementation..

securities-case-web-client-prototype

• Libs / frameworks / tools:
  • babeljs for ES6 support - nicer, concise version of JS
  • npm for dependency management and build lifecycle
  • mocha for test along with the expect library
• React
  • UI as a function of state
    • (state) => UI
  • pure functions
  • compose-able components
  • sync's state with UI
• Redux
  • Actions
    • all possible actions that may occur, including:
      • rest api response
      • websocket push message
      • user interaction with the UI
    • provide helpers to create actions
  • Store
    • provides a state tree
    • provides an event store for all actions
      • dispatch() for new actions
  • Reducers
    • reduce an action into a new state
    • (old_state, action) => new_state
    • state must be immutable
  • redux-react glues everything together
• Integrated with maven
• Tested with mocha
• Sources: securities-case-web-client-prototype/src/main/js
• Tests: securities-case-web-client-prototype/src/test/js

# First install node.js and then..

cd securities-case-web-client-prototype
npm install                             # Install deps
npm run test                            # Run tests
npm run build                           # Build

cd ../securities-case-web
mvn spring-boot:run                     # Start app server
google-chrome http://localhost:8080/    # View prototype in browser

# Maven integration
# npm install, build and test are integrated
# with the maven build cycle...

mvn clean install

# ...will get dependencies, build and test the prototype
# See securities-case-web-client-prototype/pom.xml for more

# Test output

  Action
    for get instruments
      ✓ should exist
      ✓ should be of the correct type
      ✓ should have instruments
    for select instrument
      ✓ should exist
      ✓ should be of the correct type
      ✓ should have code
    for get message
      ✓ should exist
      ✓ should be of the correct type
      ✓ should have message

  Types
    ✓ get instrument
    ✓ select_instrument
    ✓ get_message

  Reducer
    of filter instruments
      for unknown action
        ✓ state should exist
        ✓ state should have 0 instruments
        ✓ state should have null selected
      for get instruments
        ✓ state should exist
        ✓ state should have 4 instruments
        ✓ states first instrument should have code null
      for select instrument
        ✓ state should exist
        ✓ state should have correct selected instrument
    of messages
      for unknown action
        ✓ state should exist
        ✓ state should have 0 messages
        ✓ state should have null selected
      for get messages
        ✓ state should exist
        ✓ state should have 1 messages
        ✓ state should prepend messages
      for select instrument
        ✓ state should exist
        ✓ state should have correct selected instrument

  Store
    ✓ exists
    default state
      ✓ exists
      for filter instruments
        ✓ exists
        ✓ contains 0 instruments
        ✓ has null selected
      for messages
        ✓ exists
        ✓ contains 0 messages
        ✓ has null selected
    state after get_instruments action
      for filter instruments
        ✓ contains 4 instruments
        ✓ first instrument is null
    state after get_message action
      for messages
        ✓ contains 1 messages
    state after another get_message action
      for messages
        ✓ contains 2 messages
        ✓ message should be prepended
    state after select_instrument action
      for filter instruments
        ✓ has 9 selected
      for messages
        ✓ has 9 selected


  43 passing (19ms)