PostComments API into CSV

main.go

package main

import (
	"io/ioutil"
	"net/http"
	"encoding/json"
	"encoding/csv"
	"strings"
	"fmt"
	"strconv"
	"os"
	"log"
)

var (
	postAPI = "https://jsonplaceholder.typicode.com/posts"
	commentsAPI = "https://jsonplaceholder.typicode.com/comments"
)

type Post struct {
	UserID int `json:"userId"`
	ID int
	Title string
	Body string
	Comments string
}

type Comment struct {
	PostId int 
	ID int
	Body string
}

func getHttpApiResponse(api string) ([]byte, error) {
	resp, err := http.Get(api)
	if err != nil {
		return nil, err
	}
	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	return body, nil
}

func parseCommentApiResponse(rawData []byte) ([]Comment, error) {
	var comments []Comment
	err := json.Unmarshal(rawData, &comments)
	if err != nil {
		return nil, err
	}
	return comments, err
}

func parsePostApiResponse(rawData []byte) ([]Post, error) {
	var posts []Post
	err := json.Unmarshal(rawData, &posts)
	if err != nil {
		return nil, err
	}
	return posts, err
}

func main() {

	rawPosts, err := getHttpApiResponse(postAPI)
	if err != nil {
		panic(err)
	}
	rawComments, err := getHttpApiResponse(commentsAPI)
	if err != nil {
		panic(err)
	}

	posts, err := parsePostApiResponse(rawPosts)
	comments, err := parseCommentApiResponse(rawComments)

	for i := 0; i < len(posts); i++ {
		post := posts[i]

		filteredComments := []string{}
		for i := 0; i < len(comments); i++ {
			comment := comments[i]
			if comment.PostId == post.ID {
				filteredComments = append(filteredComments, comment.Body)
			}
		}

		posts[i].Comments = strings.Join(filteredComments, " | ")
		// fmt.Println("---")
	}
	// fmt.Printf("POSTS\n%v\n\n\n", posts)

	csvFile, err := os.Create("posts.csv")
	if err != nil {
		log.Fatalf("failed creating file: %s", err)
	}

	csvwriter := csv.NewWriter(csvFile)
	
	// postsToCSV = [][]string{}
	for _, post := range posts {
		postId := strconv.Itoa(post.ID)
		// postTitle := strconv.Itoa(post.Title)
		// postsToCSV := append(postsToCSV, []string{postId, postTitle, post.Comments})
		csvPost := []string{postId,post.Body, post.Title, post.Comments}
		// rowcsv := fmt.Sprintf("%v,%v,%v", postId, post.Title, post.Comments)
		_ = csvwriter.Write(csvPost)
	}
	csvwriter.Flush()
	csvFile.Close()
	fmt.Printf("END") //%v",posts)
}

main_test.go

package main

import (
	"testing"
	"fmt"
)

func TestHttpClientCall(t  *testing.T) {
	resp, err := getHttpApiResponse(postAPI)
	if err != nil {
		t.Fail()
	}
	fmt.Printf("%v", resp)
}


func TestParseResponse(t  *testing.T) {
	rawData, _ := getHttpApiResponse(postAPI)

	resp, err := parsePostApiResponse(rawData)
	if err != nil {
		t.Fail()
	}
	fmt.Printf("POST=====\n%v\n", resp)

	rawData, _ = getHttpApiResponse(commentsAPI)
	resp, err = parseCommentApiResponse(rawData)
	if err != nil {
		t.Fail()
	}
	fmt.Printf("COMMENT=====\n%v\n", resp)
}