Weather Client

A simple command line utility to query the OpenWeatherMap Current Weather Data API

./weather -location Seattle -units imperial
{Clouds few clouds 81.86 Seattle}

Usage

• Prior to use, install Golang
• Create an account on Open Weather Map and sign up for an API key
• Create an environment variable for your Open Weather Map API key: export WEATHERAPI=YourOpenWeatherMapAPIKey
• Clone weather repo to local machine and change to that directory
• Build weather client: go build -o weather ./cmd/main.go
• ./weather -location Seattle -units imperial

Goals

To learn and become more familiar with the following aspects of the Go language:

• testing
• functions and methods
• structs
• HTTP Client
• writing clear code

Application Requirements

• I want to be able to connect an external REST API -- OpenWeatherAPI
• I want to be able to pass an formatted URL to the REST API
• I want to take the json response from the API and populate a response struct
• I want to use the reponse struct to populate a final struct for display to the user

Testing Requirements

• I want to test the behavior of the application code as it relates to an external API and the Go standard library
• I don't want to test the OpenWeather API since I assume they test their code
• I don't want to test the Go standard library since they do test their code

Tests

• TestFormatURL: Given a set of input parameters, can the FormatURL method correctly put together a url string
• TestGetWeather: Given a test web sever w/ data, can the Get method correctly return a Weather struct with the fields populated
• TestNewClient: Given a set of input parameters, can the NewClient func correctly return a Client struct with the fields populated
• TestUnmarshallJson: Given an io.Reader, can the ParseResponse func correctly decode json to a Weather struct

Structs and Methods

Client: Holds all info needed to make a call to the OpenWeather API

• FormatURL: Builds a URL based off of input parameters. URL will be used in call to open OpenWeather API
• Get: Makes the call to OpenWeatherAPI, converts JSON to struct for use in customer output

WeatherResponse: Populated from OpenWeather API JSON response. Not fit for output to customer

Weather: Populated from WeatherResponse struct. Used to present data to customer

Standalone Funcs

NewClient: Generates a Client struct for use in querying the OpenWeather API

ParseResponse: Accepts an io.Reader and decodes JSON into WeatherResponse struct. WeatherResponse struct in then used to populate a Weather struct.