6. net http

In this course, we'll be using Go's standard net/http package and the http.Client to make HTTP requests. In fact, we've already been using it! The http.Get function uses the http.DefaultClient under the hood.

Making a Request

import (
	"fmt"
	"io"
	"net/http"
)

func getProjects() ([]byte, error) {
	res, err := http.Get("https://api.jello.com/projects")
	if err != nil {
		return nil, fmt.Errorf("error making request: %w", err)
	}
	defer res.Body.Close()

	data, err := io.ReadAll(res.Body)
	if err != nil {
		return nil, fmt.Errorf("error reading response: %w", err)
	}
	return data, nil
}

We'll go in-depth on the various things happening here later, but let's cover some basics for now.

• http.Get uses the http.DefaultClient to make a request to the given url

• res is the HTTP response that comes back from the server

• defer res.Body.Close() ensures that the response body is properly closed after reading. Not doing so can cause memory issues.

• io.ReadAll reads the response body into a slice of bytes []byte called data

Assignment

There is a bug in the getIssueData function! It's returning the entire http.Response instead of the data from the body (a slice of bytes). Fix it so that it returns []byte.

1

Use io.ReadAll to read the .Body of the response

Read the response body into a byte slice using io.ReadAll(res.Body).

2

Return the resulting []byte

Return the []byte result (and handle any read errors).

package main

import (
	"fmt"
	"io"
	"net/http"
)

func getIssueData(url string) ([]byte, error) {
	res, err := http.Get(url)
	if err != nil {
		return nil, fmt.Errorf("error creating request: %w", err)
	}
	defer res.Body.Close()
	return res, nil
}

Solution

package main

import (
	"fmt"
	"io"
	"net/http"
)

func getIssueData(url string) ([]byte, error) {
	res, err := http.Get(url)
	if err != nil {
		return nil, fmt.Errorf("error creating request: %w", err)
	}
	defer res.Body.Close()
	
	// SOLUTION BELOW
	data, err := io.ReadAll(res.Body)
	if err != nil {
		return nil, fmt.Errorf("error reading response: %w", err)	
	}
	return data, nil
}