refactor lib

src/lib/decrypt.ts

@@ -69,5 +69,5 @@ export const decryptDownload = (source: Buffer, trackId: string) => {
 };
 
 export const trackIsEncrypted = (url: string) => {
-  return url.includes("/mobile/") || url.includes("/media/");
-}
+  return url.includes('/mobile/') || url.includes('/media/');
+};

src/lib/get-url.ts

@@ -1,19 +1,19 @@
 import axios from 'axios';
 import {getSongFileName} from '../lib/decrypt';
 import instance from '../lib/request';
-import type {trackType} from '../types'
+import type {trackType} from '../types';
 
 interface userData {
-  license_token: string,
-  can_stream_lossless: boolean,
-  can_stream_hq: boolean,
+  license_token: string;
+  can_stream_lossless: boolean;
+  can_stream_hq: boolean;
 }
 
 class WrongLicense extends Error {
   constructor(format: string) {
-    super()
-    this.name = "WrongLicense"
-    this.message = `Your account can't stream ${format} tracks`
+    super();
+    this.name = 'WrongLicense';
+    this.message = `Your account can't stream ${format} tracks`;
   }
 }
 
@@ -31,16 +31,15 @@ const dzAuthenticate = async (): Promise<userData> => {
     license_token: data.results.USER.OPTIONS.license_token,
     can_stream_lossless: data.results.USER.OPTIONS.web_lossless || data.results.USER.OPTIONS.mobile_loseless,
     can_stream_hq: data.results.USER.OPTIONS.web_hq || data.results.USER.OPTIONS.mobile_hq,
-  }
+  };
   return user_data;
 };
 
 const getTrackUrlFromServer = async (track_token: string, format: string): Promise<string | null> => {
   const user = user_data ? user_data : await dzAuthenticate();
-  if (
-    format === "FLAC" && !user.can_stream_lossless ||
-    format === "MP3_320" && !user.can_stream_hq
-  ) throw new WrongLicense(format);
+  if ((format === 'FLAC' && !user.can_stream_lossless) || (format === 'MP3_320' && !user.can_stream_hq)) {
+    throw new WrongLicense(format);
+  }
 
   const {data} = await instance.post('https://media.deezer.com/v1/get_url', {
     license_token: user.license_token,
@@ -53,9 +52,9 @@ const getTrackUrlFromServer = async (track_token: string, format: string): Promi
     track_tokens: [track_token],
   });
 
-  if (data.data.length) {
+  if (data.data.length > 0) {
     if (data.data[0].errors) {
-      throw new Error(`Deezer error: ${JSON.stringify(data)}`)
+      throw new Error(`Deezer error: ${JSON.stringify(data)}`);
     }
     return data.data[0].media.length > 0 ? data.data[0].media[0].sources[0].url : null;
   }
@@ -67,52 +66,47 @@ const getTrackUrlFromServer = async (track_token: string, format: string): Promi
  * @param quality 1 = 128kbps, 3 = 320kbps and 9 = flac (around 1411kbps)
  */
 export const getTrackDownloadUrl = async (track: trackType, quality: number): Promise<string | null> => {
-  let url: string | null = null;
-  let wrongLicense;
-  let formatName;
-  if (quality === 9) {
-    formatName = 'FLAC';
-  } else if (quality === 3) {
-    formatName = 'MP3_320';
-  } else {
-    formatName = 'MP3_128';
+  let formatName: string;
+  switch (quality) {
+    case 9:
+      formatName = 'FLAC';
+      break;
+    case 3:
+      formatName = 'MP3_320';
+    case 1:
+      formatName = 'MP3_128';
+    default:
+      throw new Error(`Unknow quality ${quality}`);
   }
 
   // Get URL with the official API
   try {
-    url = await getTrackUrlFromServer(track.TRACK_TOKEN, formatName)
-    if (url) {
-      let isUrlOk = await testUrl(url)
-      if (isUrlOk) return url;
+    const url = await getTrackUrlFromServer(track.TRACK_TOKEN, formatName);
+    if (url && (await testUrl(url))) {
+      return url;
     }
-    url = null;
-  } catch (e) {
-    if (e instanceof WrongLicense) {
-      wrongLicense = true;
+  } catch (err) {
+    if (err instanceof WrongLicense) {
+      throw new Error(`Your account can't stream ${formatName} tracks`);
     } else {
-      throw e;
+      throw err;
     }
-    url = null;
   }
+
   // Fallback to the old method
-  if (!url) {
-    const cdn = track.MD5_ORIGIN[0]; // cdn destination
-    const filename = getSongFileName(track, quality); // encrypted file name
-    url = `https://e-cdns-proxy-${cdn}.dzcdn.net/mobile/1/${filename}`;
-    let isUrlOk = await testUrl(url)
-    if (isUrlOk) return url
-    url = null
+  const filename = getSongFileName(track, quality); // encrypted file name
+  const url = `https://e-cdns-proxy-${track.MD5_ORIGIN[0]}.dzcdn.net/mobile/1/${filename}`;
+  if (await testUrl(url)) {
+    return url;
   }
-  if (wrongLicense) throw new Error(`Your account can't stream ${formatName} tracks`);
-  return url
-}
+  return null;
+};
 
 const testUrl = async (url: string): Promise<boolean> => {
   try {
     let response = await axios.head(url);
-    if (Number(response.headers["content-length"]) > 0) return true;
-    return false;
-  } catch (e) {
+    return Number(response.headers['content-length']) > 0 ? true : false;
+  } catch (err) {
     return false;
   }
-}
+};