Only use fmt.Sprint() when necessary

cmd/backend/files.go

@@ -3,6 +3,7 @@ package backend
 import (
 	"fmt"
 	"io"
+	"log"
 	"os"
 )
 
@@ -19,10 +20,30 @@ func CopyFile(src, dst string) error {
 	}
 	defer dstFile.Close()
 
-	_, err = io.Copy(dstFile, srcFile)
+	if _, err = io.Copy(dstFile, srcFile); err != nil {
-	if err != nil {
 		return fmt.Errorf("error copying file: %v", err)
 	}
 
 	return dstFile.Sync()
 }
+
+func WriteFile(path string, src io.Reader) error {
+	file, err := os.Create(path)
+	if err != nil {
+		log.Println(err)
+		return fmt.Errorf("error creating file: %v", err)
+	}
+	defer file.Close()
+
+	if _, err = io.Copy(file, src); err != nil {
+		log.Println(err)
+		return fmt.Errorf("error copying file: %v", err)
+	}
+
+	if err = file.Sync(); err != nil {
+		log.Println(err)
+		return fmt.Errorf("error syncing file: %v", err)
+	}
+
+	return nil
+}

cmd/backend/rss.go

@@ -55,7 +55,7 @@ func GenerateRSS(c *Config, db *DB) (*string, error) {
 		}
 
 		item := &rss.Item{
-			Author:      fmt.Sprint(user.FirstName, " ", user.LastName),
+			Author:      user.FirstName + " " + user.LastName,
 			Categories:  tagNames,
 			Description: articleDescription,
 			Guid:        string(article.ID),

cmd/calls/pdf.go

@@ -2,7 +2,6 @@ package calls
 
 import (
 	"encoding/json"
-	"fmt"
 	"log"
 	"net/http"
 	"os"
@@ -43,6 +42,6 @@ func ServePDF(c *b.Config) http.HandlerFunc {
 			return
 		}
 
-		http.ServeFile(w, r, fmt.Sprint(c.PDFDir, "/", r.PathValue("id")))
+		http.ServeFile(w, r, c.PDFDir+"/"+r.PathValue("id"))
 	}
 }

cmd/frontend/articles.go

@@ -547,7 +547,7 @@ func UploadArticleImage(c *b.Config, s *b.CookieStore) http.HandlerFunc {
 			return
 		}
 
-		url := fmt.Sprint(c.Domain, "/image/serve/", filename)
+		url := c.Domain + "/image/serve/" + filename
 		w.Header().Set("Content-Type", "application/json")
 		json.NewEncoder(w).Encode(url)
 	}

cmd/frontend/issues.go

@@ -61,7 +61,7 @@ func PublishLatestIssue(c *b.Config, db *b.DB, s *b.CookieStore) http.HandlerFun
 
 		article := &b.Article{
 			Title:         title,
-			EncURL:        fmt.Sprint(c.Domain, "/image/serve/", imgFileName),
+			EncURL:        c.Domain + "/image/serve/" + imgFileName,
 			EncLength:     int(imgInfo.Size()),
 			EncType:       mime.TypeByExtension(filepath.Ext(imgAbsName)),
 			Published:     true,

cmd/frontend/pdf.go

@@ -2,10 +2,8 @@ package frontend
 
 import (
 	"fmt"
-	"io"
 	"log"
 	"net/http"
-	"os"
 	"path/filepath"
 
 	"github.com/google/uuid"
@@ -53,22 +51,14 @@ func UploadPDF(c *b.Config, s *b.CookieStore) http.HandlerFunc {
 		}
 
 		filename := fmt.Sprint(uuid.New(), ".pdf")
-		absFilepath, err := filepath.Abs(fmt.Sprint(c.PDFDir, "/", filename))
+		absFilepath, err := filepath.Abs(c.PDFDir + "/" + filename)
 		if err != nil {
 			log.Println(err)
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
 
-		pdf, err := os.Create(absFilepath)
+		if err = b.WriteFile(absFilepath, file); err != nil {
-		if err != nil {
-			log.Println(err)
-			http.Error(w, err.Error(), http.StatusInternalServerError)
-			return
-		}
-		defer pdf.Close()
-
-		if _, err = io.Copy(pdf, file); err != nil {
 			log.Println(err)
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return