Replace fatal error handling with proper error propagation and logging

cmd/main.go

@@ -24,7 +24,8 @@ func main() {
 		var posts []models.Post = nil
 		err, posts := appContext.PostService.GetPostsFromApi(ctx, appContext.Tag, appContext.Instance)
 		if err != nil {
-			log.Fatal(err)
+			log.Println(err)
+			return
 		}
 
 		var existingPostIds = appContext.PostService.GetExistingPostIds()

internal/services/postService.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"log"
 	"net/http"
 	"strings"
 
@@ -26,24 +25,20 @@ func (*PostService) GetPostsFromApi(ctx context.Context, tag string, instance st
 	var requestUrl = instance + "/api/v1/timelines/tag/" + tag + "?limit=40"
 	req, err := http.NewRequestWithContext(ctx, "GET", requestUrl, nil)
 	if err != nil {
-		log.Fatal(err)
 		return err, nil
 	}
 
 	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
-		log.Fatal(err)
 		return err, nil
 	}
 	if resp.StatusCode != 200 || strings.Split(strings.ToLower(resp.Header.Get("Content-Type")), ";")[0] != "application/json" {
-		log.Fatal("Status code:", resp.StatusCode, " Content-Type:", resp.Header.Get("Content-Type"))
-		return err, nil
+		return fmt.Errorf("Status code:", resp.StatusCode, " Content-Type:", resp.Header.Get("Content-Type")), nil
 	}
 
 	var posts []models.Post = nil
 	err = json.NewDecoder(resp.Body).Decode(&posts)
 	if err != nil {
-		log.Fatal(err)
 		return err, nil
 	}
 	// defer: it basically means "do this later when the function returns"