refactor(misc): replace fmt.Errorf with errors.New where possible

No need to to invoke the whole Printf machinery for constant strings. While
this shouldn't have an impact on memory consumption nor allocation (as
constructing errors to return is never in a hot path), this should reduce a bit
the code size, as errors.New will be inlined to a simple struct initialization
instead of a function call.

Author: jvoisin

client/client.go

@@ -125,7 +125,7 @@ func (c *Client) UserByID(userID int64) (*User, error) {
 
 // UserByUsername returns a single user.
 func (c *Client) UserByUsername(username string) (*User, error) {
-	body, err := c.request.Get(fmt.Sprintf("/v1/users/%s", username))
+	body, err := c.request.Get("/v1/users/" + username)
 	if err != nil {
 		return nil, err
 	}

internal/cli/reset_password.go

@@ -4,6 +4,7 @@
 package cli // import "miniflux.app/v2/internal/cli"
 
 import (
+	"errors"
 	"fmt"
 
 	"miniflux.app/v2/internal/model"
@@ -19,7 +20,7 @@ func resetPassword(store *storage.Storage) {
 	}
 
 	if user == nil {
-		printErrorAndExit(fmt.Errorf("user not found"))
+		printErrorAndExit(errors.New("user not found"))
 	}
 
 	userModificationRequest := &model.UserModificationRequest{

internal/config/parser.go

@@ -7,6 +7,7 @@ import (
 	"bufio"
 	"bytes"
 	"crypto/rand"
+	"errors"
 	"fmt"
 	"io"
 	"net/url"
@@ -60,7 +61,7 @@ func (cp *configParser) postParsing() error {
 
 	scheme := strings.ToLower(parsedURL.Scheme)
 	if scheme != "https" && scheme != "http" {
-		return fmt.Errorf("BASE_URL scheme must be http or https")
+		return errors.New("BASE_URL scheme must be http or https")
 	}
 
 	cp.options.options["BASE_URL"].ParsedStringValue = baseURL
@@ -294,7 +295,7 @@ func readSecretFileValue(filename string) (string, error) {
 
 	value := string(bytes.TrimSpace(data))
 	if value == "" {
-		return "", fmt.Errorf("secret file is empty")
+		return "", errors.New("secret file is empty")
 	}
 
 	return value, nil

internal/config/validators.go

@@ -4,6 +4,7 @@
 package config // import "miniflux.app/v2/internal/config"
 
 import (
+	"errors"
 	"fmt"
 	"slices"
 	"strconv"
@@ -29,7 +30,7 @@ func validateListChoices(inputValues, choices []string) error {
 func validateGreaterThan(rawValue string, min int) error {
 	intValue, err := strconv.Atoi(rawValue)
 	if err != nil {
-		return fmt.Errorf("value must be an integer")
+		return errors.New("value must be an integer")
 	}
 	if intValue > min {
 		return nil
@@ -40,7 +41,7 @@ func validateGreaterThan(rawValue string, min int) error {
 func validateGreaterOrEqualThan(rawValue string, min int) error {
 	intValue, err := strconv.Atoi(rawValue)
 	if err != nil {
-		return fmt.Errorf("value must be an integer")
+		return errors.New("value must be an integer")
 	}
 	if intValue >= min {
 		return nil
@@ -51,7 +52,7 @@ func validateGreaterOrEqualThan(rawValue string, min int) error {
 func validateRange(rawValue string, min, max int) error {
 	intValue, err := strconv.Atoi(rawValue)
 	if err != nil {
-		return fmt.Errorf("value must be an integer")
+		return errors.New("value must be an integer")
 	}
 	if intValue < min || intValue > max {
 		return fmt.Errorf("value must be between %d and %d", min, max)

internal/googlereader/handler.go

@@ -126,8 +126,7 @@ func checkOutputFormat(r *http.Request) error {
 		output = request.QueryStringParam(r, "output", "")
 	}
 	if output != "json" {
-		err := fmt.Errorf("googlereader: only json output is supported")
-		return err
+		return errors.New("googlereader: only json output is supported")
 	}
 	return nil
 }
@@ -280,7 +279,7 @@ func (h *handler) editTagHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if len(addTags) == 0 && len(removeTags) == 0 {
-		err = fmt.Errorf("googlreader: add or/and remove tags should be supplied")
+		err = errors.New("googlreader: add or/and remove tags should be supplied")
 		json.ServerError(w, r, err)
 		return
 	}
@@ -1014,7 +1013,7 @@ func (h *handler) userInfoHandler(w http.ResponseWriter, r *http.Request) {
 		json.ServerError(w, r, err)
 		return
 	}
-	userInfo := userInfoResponse{UserID: fmt.Sprint(user.ID), UserName: user.Username, UserProfileID: fmt.Sprint(user.ID), UserEmail: user.Username}
+	userInfo := userInfoResponse{UserID: strconv.FormatInt(user.ID, 10), UserName: user.Username, UserProfileID: strconv.FormatInt(user.ID, 10), UserEmail: user.Username}
 	json.OK(w, r, userInfo)
 }
 
@@ -1048,7 +1047,7 @@ func (h *handler) streamItemIDsHandler(w http.ResponseWriter, r *http.Request) {
 	)
 
 	if len(rm.Streams) != 1 {
-		json.ServerError(w, r, fmt.Errorf("googlereader: only one stream type expected"))
+		json.ServerError(w, r, errors.New("googlereader: only one stream type expected"))
 		return
 	}
 	switch rm.Streams[0].Type {

internal/googlereader/item.go

@@ -4,6 +4,7 @@
 package googlereader // import "miniflux.app/v2/internal/googlereader"
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
 	"strconv"
@@ -58,7 +59,7 @@ func parseItemID(itemIDValue string) (int64, error) {
 func parseItemIDsFromRequest(r *http.Request) ([]int64, error) {
 	items := r.Form[paramItemIDs]
 	if len(items) == 0 {
-		return nil, fmt.Errorf("googlereader: no items requested")
+		return nil, errors.New("googlereader: no items requested")
 	}
 
 	itemIDs := make([]int64, len(items))

internal/googlereader/request_modifier.go

@@ -49,8 +49,8 @@ func (r RequestModifiers) String() string {
 
 	results = append(results, fmt.Sprintf("Count: %d", r.Count))
 	results = append(results, fmt.Sprintf("Offset: %d", r.Offset))
-	results = append(results, fmt.Sprintf("Sort Direction: %s", r.SortDirection))
-	results = append(results, fmt.Sprintf("Continuation Token: %s", r.ContinuationToken))
+	results = append(results, "Sort Direction: "+r.SortDirection)
+	results = append(results, "Continuation Token: "+r.ContinuationToken)
 	results = append(results, fmt.Sprintf("Start Time: %d", r.StartTime))
 	results = append(results, fmt.Sprintf("Stop Time: %d", r.StopTime))
 

internal/integration/apprise/apprise.go

@@ -6,6 +6,7 @@ package apprise
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log/slog"
 	"net/http"
@@ -29,7 +30,7 @@ func NewClient(serviceURL, baseURL string) *Client {
 
 func (c *Client) SendNotification(feed *model.Feed, entries model.Entries) error {
 	if c.baseURL == "" || c.servicesURL == "" {
-		return fmt.Errorf("apprise: missing base URL or services URL")
+		return errors.New("apprise: missing base URL or services URL")
 	}
 
 	for _, entry := range entries {

internal/integration/espial/espial.go

@@ -6,6 +6,7 @@ package espial // import "miniflux.app/v2/internal/integration/espial"
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"time"
@@ -27,7 +28,7 @@ func NewClient(baseURL, apiKey string) *Client {
 
 func (c *Client) CreateLink(entryURL, entryTitle, espialTags string) error {
 	if c.baseURL == "" || c.apiKey == "" {
-		return fmt.Errorf("espial: missing base URL or API key")
+		return errors.New("espial: missing base URL or API key")
 	}
 
 	apiEndpoint, err := urllib.JoinBaseURLAndPath(c.baseURL, "/api/add")

internal/integration/instapaper/instapaper.go

@@ -4,6 +4,7 @@
 package instapaper // import "miniflux.app/v2/internal/integration/instapaper"
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -25,7 +26,7 @@ func NewClient(username, password string) *Client {
 
 func (c *Client) AddURL(entryURL, entryTitle string) error {
 	if c.username == "" || c.password == "" {
-		return fmt.Errorf("instapaper: missing username or password")
+		return errors.New("instapaper: missing username or password")
 	}
 
 	values := url.Values{}