style: prefer stdlib idioms for errors and http methods

internal/deezer/client.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -62,7 +63,7 @@ func (c *Client) FetchResource(ctx context.Context, kind Kind, id string) (Resou
 		return nil, err
 	}
 
-	payload := map[string]interface{}{
+	payload := map[string]any{
 		"nb":     10000,
 		"start":  0,
 		"lang":   "en",
@@ -78,7 +79,7 @@ func (c *Client) FetchResource(ctx context.Context, kind Kind, id string) (Resou
 	}
 
 	url := fmt.Sprintf("https://www.deezer.com/ajax/gw-light.php?method=deezer.page%s&input=3&api_version=1.0&api_token=%s", kind.pageMethod(), c.Session.APIToken)
-	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewBuffer(jsonData))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewBuffer(jsonData))
 	if err != nil {
 		return nil, err
 	}
@@ -109,12 +110,12 @@ func (c *Client) FetchResource(ctx context.Context, kind Kind, id string) (Resou
 		{`"DATA_ERROR":"song::getData"`, "invalid track ID"},
 	} {
 		if strings.Contains(bodyStr, check.marker) {
-			return nil, fmt.Errorf("%s", check.errMsg)
+			return nil, errors.New(check.errMsg)
 		}
 	}
 
 	if strings.Contains(bodyStr, `"results":{}`) {
-		return nil, fmt.Errorf("unexpected response")
+		return nil, errors.New("unexpected response")
 	}
 
 	if err := resource.decode(body); err != nil {
@@ -132,7 +133,7 @@ func (c *Client) FetchMedia(ctx context.Context, track *Track, quality string) (
 	}
 
 	reqBody := fmt.Sprintf(`{"license_token":"%s","media":[{"type":"FULL","formats":%s}],"track_tokens":["%s"]}`, c.Session.LicenseToken, qualityFormats[quality], track.TrackToken)
-	req, err := http.NewRequestWithContext(ctx, "POST", "https://media.deezer.com/v1/get_url", bytes.NewBuffer([]byte(reqBody)))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, "https://media.deezer.com/v1/get_url", bytes.NewBuffer([]byte(reqBody)))
 	if err != nil {
 		return nil, err
 	}
@@ -159,20 +160,20 @@ func (c *Client) FetchMedia(ctx context.Context, track *Track, quality string) (
 
 	if len(media.Errors) > 0 {
 		if media.Errors[0].Code == 1000 {
-			return nil, fmt.Errorf("invalid license token")
+			return nil, errors.New("invalid license token")
 		}
-		return nil, fmt.Errorf("%s", media.Errors[0].Message)
+		return nil, errors.New(media.Errors[0].Message)
 	}
 
 	if len(media.Data) > 0 && len(media.Data[0].Errors) > 0 {
 		if media.Data[0].Errors[0].Code == 2002 {
-			return nil, fmt.Errorf("invalid track token")
+			return nil, errors.New("invalid track token")
 		}
-		return nil, fmt.Errorf("%s", media.Data[0].Errors[0].Message)
+		return nil, errors.New(media.Data[0].Errors[0].Message)
 	}
 
 	if len(media.Data) == 0 || len(media.Data[0].Media) == 0 || len(media.Data[0].Media[0].Sources) == 0 {
-		return nil, fmt.Errorf("no sources found")
+		return nil, errors.New("no sources found")
 	}
 
 	return &media, nil
@@ -180,7 +181,7 @@ func (c *Client) FetchMedia(ctx context.Context, track *Track, quality string) (
 
 func (c *Client) FetchCoverImage(ctx context.Context, track *Track) ([]byte, error) {
 	url := fmt.Sprintf("https://e-cdn-images.dzcdn.net/images/cover/%s/500x500-000000-80-0-0.jpg", track.Cover)
-	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -199,7 +200,7 @@ func (c *Client) FetchCoverImage(ctx context.Context, track *Track) ([]byte, err
 }
 
 func (c *Client) MediaStream(ctx context.Context, media *Media) (io.ReadCloser, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", media.URL(), nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, media.URL(), nil)
 	if err != nil {
 		return nil, err
 	}

internal/deezer/gateway.go

@@ -6,6 +6,7 @@ import (
 	"crypto/aes"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"math/rand/v2"
@@ -47,7 +48,7 @@ func gatewayEnv() (string, string, error) {
 	apiKey := os.Getenv("DEEZER_MOBILE_API_KEY")
 	gwKey := os.Getenv("DEEZER_MOBILE_GW_KEY")
 	if apiKey == "" || gwKey == "" {
-		return "", "", fmt.Errorf("DEEZER_MOBILE_API_KEY and DEEZER_MOBILE_GW_KEY must be set to use email/password login")
+		return "", "", errors.New("DEEZER_MOBILE_API_KEY and DEEZER_MOBILE_GW_KEY must be set to use email/password login")
 	}
 
 	if len(gwKey) != aes.BlockSize {
@@ -89,7 +90,7 @@ func (m *mobileClient) login(ctx context.Context, email, password string) (*Cred
 }
 
 func (m *mobileClient) authenticate(ctx context.Context) (string, string, string, error) {
-	body, err := m.gatewayRequest(ctx, "mobile_auth", "GET", "uniq_id", genUniqID(), nil)
+	body, err := m.gatewayRequest(ctx, "mobile_auth", http.MethodGet, "uniq_id", genUniqID(), nil)
 	if err != nil {
 		return "", "", "", err
 	}
@@ -104,10 +105,10 @@ func (m *mobileClient) authenticate(ctx context.Context) (string, string, string
 	}
 
 	if strings.Contains(string(body), "Undefined or invalid API key") {
-		return "", "", "", fmt.Errorf("DEEZER_MOBILE_API_KEY is invalid")
+		return "", "", "", errors.New("DEEZER_MOBILE_API_KEY is invalid")
 	}
 	if strings.Contains(string(body), "GATEWAY_ERROR") || res.Results.Token == "" {
-		return "", "", "", fmt.Errorf("unexpected response from gateway")
+		return "", "", "", errors.New("unexpected response from gateway")
 	}
 
 	encrypted, err := hex.DecodeString(res.Results.Token)
@@ -121,7 +122,7 @@ func (m *mobileClient) authenticate(ctx context.Context) (string, string, string
 	}
 
 	if len(decrypted) < 96 {
-		return "", "", "", fmt.Errorf("unexpected response from gateway")
+		return "", "", "", errors.New("unexpected response from gateway")
 	}
 
 	token := string(decrypted[0:64])
@@ -138,7 +139,7 @@ func (m *mobileClient) checkToken(ctx context.Context, token, tokenKey string) e
 	}
 	authToken := hex.EncodeToString(encrypted)
 
-	body, err := m.gatewayRequest(ctx, "api_checkToken", "GET", "auth_token", authToken, nil)
+	body, err := m.gatewayRequest(ctx, "api_checkToken", http.MethodGet, "auth_token", authToken, nil)
 	if err != nil {
 		return err
 	}
@@ -150,7 +151,7 @@ func (m *mobileClient) checkToken(ctx context.Context, token, tokenKey string) e
 		return err
 	}
 	if res.Results == "" {
-		return fmt.Errorf("unexpected response from gateway")
+		return errors.New("unexpected response from gateway")
 	}
 	m.sid = res.Results
 
@@ -183,13 +184,13 @@ func (m *mobileClient) userAuth(ctx context.Context, email, password, userKey st
 		return "", "", err
 	}
 
-	body, err := m.gatewayRequest(ctx, "mobile_userAuth", "POST", "", "", jsonBody)
+	body, err := m.gatewayRequest(ctx, "mobile_userAuth", http.MethodPost, "", "", jsonBody)
 	if err != nil {
 		return "", "", err
 	}
 
 	if strings.Contains(string(body), "USER_AUTH_ERROR") {
-		return "", "", fmt.Errorf("invalid email or password")
+		return "", "", errors.New("invalid email or password")
 	}
 
 	var res struct {
@@ -204,7 +205,7 @@ func (m *mobileClient) userAuth(ctx context.Context, email, password, userKey st
 	}
 
 	if res.Results.ARL == "" || res.Results.UserID == 0 {
-		return "", "", fmt.Errorf("unexpected response from gateway")
+		return "", "", errors.New("unexpected response from gateway")
 	}
 
 	return res.Results.ARL, res.Results.BlogName, nil
@@ -220,7 +221,7 @@ func (m *mobileClient) gatewayRequest(ctx context.Context, method, httpMethod, p
 	q.Set("method", method)
 	q.Set("api_key", m.apiKey)
 	q.Set("output", "3")
-	if httpMethod == "POST" {
+	if httpMethod == http.MethodPost {
 		q.Set("input", "3")
 	}
 	if m.sid != "" {

internal/deezer/login.go

@@ -32,7 +32,7 @@ func resolveARL(ctx context.Context, validate func(ctx context.Context, arl stri
 		return arl, nil
 	}
 
-	return "", fmt.Errorf("run 'godeez login' or export DEEZER_ARL environment variable")
+	return "", errors.New("run 'godeez login' or export DEEZER_ARL environment variable")
 }
 
 func Login(ctx context.Context, email, password string) (string, string, error) {

internal/deezer/session.go

@@ -31,7 +31,7 @@ func authenticate(ctx context.Context, arlCookie string) (*Session, error) {
 	}
 
 	url := "https://www.deezer.com/ajax/gw-light.php?method=deezer.getUserData&input=3&api_version=1.0&api_token="
-	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
 	if err != nil {
 		return nil, err
 	}

internal/download/bpm.go

@@ -3,6 +3,7 @@ package download
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -40,7 +41,7 @@ func findTrackURL(ctx context.Context, httpClient *http.Client, artist, title, d
 	values := neturl.Values{}
 	values.Add("query", fmt.Sprintf("%s %s", artist, title))
 
-	req, err := http.NewRequestWithContext(ctx, "POST", rootURL+"/searches", bytes.NewBufferString(values.Encode()))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, rootURL+"/searches", bytes.NewBufferString(values.Encode()))
 	if err != nil {
 		return "", err
 	}
@@ -102,14 +103,14 @@ func findTrackURL(ctx context.Context, httpClient *http.Client, artist, title, d
 	})
 
 	if matchURL == "" {
-		return "", fmt.Errorf("no data found")
+		return "", errors.New("no data found")
 	}
 
 	return rootURL + matchURL, nil
 }
 
 func fetchBPMPage(ctx context.Context, httpClient *http.Client, url string) (string, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
 	if err != nil {
 		return "", err
 	}
@@ -138,7 +139,7 @@ func parseBPM(html string) (bpmKey, error) {
 	modeMatch := modeRegex.FindStringSubmatch(html)
 
 	if len(bpmMatch) != 2 || len(keyMatch) != 2 || len(modeMatch) != 2 {
-		return bpmKey{}, fmt.Errorf("no data found")
+		return bpmKey{}, errors.New("no data found")
 	}
 
 	bpm := bpmMatch[1]

internal/download/genre.go

@@ -2,6 +2,7 @@ package download
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/url"
@@ -50,14 +51,14 @@ func fetchGenre(ctx context.Context, httpClient *http.Client, artist, title stri
 
 	filtered := filterTags(tags)
 	if len(filtered) == 0 {
-		return "", fmt.Errorf("no data found")
+		return "", errors.New("no data found")
 	}
 
 	return formatTags(filtered), nil
 }
 
 func fetchGenrePage(ctx context.Context, httpClient *http.Client, url string) (*goquery.Document, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
 	if err != nil {
 		return nil, err
 	}

internal/download/options.go

@@ -1,6 +1,7 @@
 package download
 
 import (
+	"errors"
 	"fmt"
 	"time"
 
@@ -27,14 +28,14 @@ func (o *Options) Validate(kind deezer.Kind) error {
 		return fmt.Errorf("invalid quality option: %s", o.Quality)
 	}
 	if o.Timeout <= 0 {
-		return fmt.Errorf("timeout must be a positive duration")
+		return errors.New("timeout must be a positive duration")
 	}
 	if kind == deezer.KindArtist {
 		if o.Limit <= 0 {
-			return fmt.Errorf("limit must be a positive integer")
+			return errors.New("limit must be a positive integer")
 		}
 		if o.Limit > 100 {
-			return fmt.Errorf("limit must not exceed 100")
+			return errors.New("limit must not exceed 100")
 		}
 	}
 

internal/download/progress.go

@@ -2,7 +2,7 @@ package download
 
 import (
 	"fmt"
-	"math/rand"
+	"math/rand/v2"
 	"os"
 	"time"
 

internal/store/download_info.go

@@ -2,6 +2,7 @@ package store
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"time"
 
@@ -24,12 +25,12 @@ func (s *Store) DownloadInfo(trackID string) (*DownloadInfo, error) {
 	if err := s.db.View(func(tx *bbolt.Tx) error {
 		b := tx.Bucket(trackBucket)
 		if b == nil {
-			return fmt.Errorf("bucket not found")
+			return errors.New("bucket not found")
 		}
 
 		data := b.Get([]byte(trackID))
 		if data == nil {
-			return fmt.Errorf("not found")
+			return errors.New("not found")
 		}
 		return json.Unmarshal(data, &info)
 	}); err != nil {

internal/store/store.go

@@ -6,19 +6,19 @@ import (
 	"path/filepath"
 	"time"
 
-	bolt "go.etcd.io/bbolt"
+	"go.etcd.io/bbolt"
 	bolterrors "go.etcd.io/bbolt/errors"
 )
 
 type Store struct {
-	db *bolt.DB
+	db *bbolt.DB
 }
 
 func Open(dir string) (*Store, error) {
-	db, err := bolt.Open(filepath.Join(dir, ".tracks.db"), 0600, &bolt.Options{Timeout: 5 * time.Second})
+	db, err := bbolt.Open(filepath.Join(dir, ".tracks.db"), 0600, &bbolt.Options{Timeout: 5 * time.Second})
 	if err != nil {
 		if errors.Is(err, bolterrors.ErrTimeout) {
-			return nil, fmt.Errorf("database is already in use by another process")
+			return nil, errors.New("database is already in use by another process")
 		}
 		return nil, fmt.Errorf("failed to open database: %w", err)
 	}

internal/tag/id3v2.go

@@ -1,7 +1,6 @@
 package tag
 
 import (
-	"fmt"
 	"strconv"
 	"strings"
 
@@ -37,7 +36,7 @@ func (t *id3v2Tagger) write(m Metadata) error {
 	t.addTag("TEXT", m.Lyricists)
 	t.addTag("TCON", m.Genre)
 	if duration, err := strconv.Atoi(m.Duration); err == nil {
-		t.addTag("TLEN", fmt.Sprintf("%d", duration*1000))
+		t.addTag("TLEN", strconv.Itoa(duration*1000))
 	}
 	t.addTag("TBPM", m.BPM)
 	t.addTag("TKEY", m.Key)

internal/update/release.go

@@ -3,6 +3,7 @@ package update
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"runtime"
@@ -46,7 +47,7 @@ func (u *Updater) Latest(ctx context.Context) (*Release, error) {
 		return nil, fmt.Errorf("failed to decode release: %w", err)
 	}
 	if release.TagName == "" {
-		return nil, fmt.Errorf("release has no tag name")
+		return nil, errors.New("release has no tag name")
 	}
 
 	return &release, nil