refactor

src/app.ts

@@ -5,8 +5,6 @@ import logger from "./logger";
 
 import {
   appendMimeTypeToClientFor,
-  axiosImageFetcher,
-  cachingImageFetcher,
   DEFAULT,
   Subsonic,
 } from "./subsonic";
@@ -17,6 +15,7 @@ import sonos, { bonobService } from "./sonos";
 import { MusicService } from "./music_service";
 import { SystemClock } from "./clock";
 import { JWTSmapiLoginTokens } from "./smapi_auth";
+import { axiosImageFetcher, cachingImageFetcher } from "./images";
 
 const config = readConfig();
 const clock = SystemClock;

src/images.ts

@@ -0,0 +1,48 @@
+
+import sharp from "sharp";
+import fse from "fs-extra";
+import path from "path";
+import { Md5 } from "ts-md5/dist/md5";
+import axios from "axios";
+
+import { CoverArt } from "./music_service";
+import { BROWSER_HEADERS } from "./utils";
+
+export type ImageFetcher = (url: string) => Promise<CoverArt | undefined>;
+
+export const cachingImageFetcher =
+  (cacheDir: string, delegate: ImageFetcher) =>
+  async (url: string): Promise<CoverArt | undefined> => {
+    const filename = path.join(cacheDir, `${Md5.hashStr(url)}.png`);
+    return fse
+      .readFile(filename)
+      .then((data) => ({ contentType: "image/png", data }))
+      .catch(() =>
+        delegate(url).then((image) => {
+          if (image) {
+            return sharp(image.data)
+              .png()
+              .toBuffer()
+              .then((png) => {
+                return fse
+                  .writeFile(filename, png)
+                  .then(() => ({ contentType: "image/png", data: png }));
+              });
+          } else {
+            return undefined;
+          }
+        })
+      );
+  };
+
+export const axiosImageFetcher = (url: string): Promise<CoverArt | undefined> =>
+  axios
+    .get(url, {
+      headers: BROWSER_HEADERS,
+      responseType: "arraybuffer",
+    })
+    .then((res) => ({
+      contentType: res.headers["content-type"],
+      data: Buffer.from(res.data, "binary"),
+    }))
+    .catch(() => undefined);

src/server.ts

@@ -35,7 +35,7 @@ import _, { shuffle } from "underscore";
 import morgan from "morgan";
 import { takeWithRepeats } from "./utils";
 import { parse } from "./burn";
-import { axiosImageFetcher, ImageFetcher } from "./subsonic";
+import { axiosImageFetcher, ImageFetcher } from "./images";
 import {
   JWTSmapiLoginTokens,
   SmapiAuthTokens,

src/subsonic.ts

@@ -15,17 +15,13 @@ import {
   AlbumSummary,
   Genre,
   Track,
-  CoverArt,
   Rating,
   AlbumQueryType,
   Artist,
   AuthFailure,
   Sortable,
 } from "./music_service";
-import sharp from "sharp";
 import _ from "underscore";
-import fse from "fs-extra";
-import path from "path";
 
 import axios, { AxiosRequestConfig } from "axios";
 import randomstring from "randomstring";
@@ -33,16 +29,8 @@ import { b64Encode, b64Decode } from "./b64";
 import logger from "./logger";
 import { assertSystem, BUrn } from "./burn";
 import { artist } from "./smapi";
+import { axiosImageFetcher, ImageFetcher } from "./images";
 
-export const BROWSER_HEADERS = {
-  accept:
-    "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
-  "accept-encoding": "gzip, deflate, br",
-  "accept-language": "en-GB,en;q=0.5",
-  "upgrade-insecure-requests": "1",
-  "user-agent":
-    "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:86.0) Gecko/20100101 Firefox/86.0",
-};
 
 export const t = (password: string, s: string) =>
   Md5.hashStr(`${password}${s}`);
@@ -353,45 +341,6 @@ export const asURLSearchParams = (q: any) => {
   return urlSearchParams;
 };
 
-export type ImageFetcher = (url: string) => Promise<CoverArt | undefined>;
-
-export const cachingImageFetcher =
-  (cacheDir: string, delegate: ImageFetcher) =>
-  async (url: string): Promise<CoverArt | undefined> => {
-    const filename = path.join(cacheDir, `${Md5.hashStr(url)}.png`);
-    return fse
-      .readFile(filename)
-      .then((data) => ({ contentType: "image/png", data }))
-      .catch(() =>
-        delegate(url).then((image) => {
-          if (image) {
-            return sharp(image.data)
-              .png()
-              .toBuffer()
-              .then((png) => {
-                return fse
-                  .writeFile(filename, png)
-                  .then(() => ({ contentType: "image/png", data: png }));
-              });
-          } else {
-            return undefined;
-          }
-        })
-      );
-  };
-
-export const axiosImageFetcher = (url: string): Promise<CoverArt | undefined> =>
-  axios
-    .get(url, {
-      headers: BROWSER_HEADERS,
-      responseType: "arraybuffer",
-    })
-    .then((res) => ({
-      contentType: res.headers["content-type"],
-      data: Buffer.from(res.data, "binary"),
-    }))
-    .catch(() => undefined);
-
 const AlbumQueryTypeToSubsonicType: Record<AlbumQueryType, string> = {
   alphabeticalByArtist: "alphabeticalByArtist",
   alphabeticalByName: "alphabeticalByName",
@@ -893,6 +842,7 @@ export class SubsonicGenericMusicLibrary implements SubsonicMusicLibrary {
 export class Subsonic implements MusicService {
   url: string;
   streamClientApplication: StreamClientApplication;
+  // todo: why is this in here?
   externalImageFetcher: ImageFetcher;
 
   constructor(

src/utils.ts

@@ -1,3 +1,13 @@
+export const BROWSER_HEADERS = {
+  accept:
+    "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
+  "accept-encoding": "gzip, deflate, br",
+  "accept-language": "en-GB,en;q=0.5",
+  "upgrade-insecure-requests": "1",
+  "user-agent":
+    "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:86.0) Gecko/20100101 Firefox/86.0",
+};
+
 export function takeWithRepeats<T>(things:T[], count: number) {
   const result = [];
   for(let i = 0; i < count; i++) {

tests/images.test.ts

@@ -0,0 +1,78 @@
+
+import tmp from "tmp";
+import fse from "fs-extra";
+import path from "path";
+import { Md5 } from "ts-md5";
+
+import sharp from "sharp";
+jest.mock("sharp");
+
+import { cachingImageFetcher } from "../src/images";
+
+describe("cachingImageFetcher", () => {
+  const delegate = jest.fn();
+  const url = "http://test.example.com/someimage.jpg";
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    jest.resetAllMocks();
+  });
+
+  describe("when there is no image in the cache", () => {
+    it("should fetch the image from the source and then cache and return it", async () => {
+      const dir = tmp.dirSync();
+      const cacheFile = path.join(dir.name, `${Md5.hashStr(url)}.png`);
+      const jpgImage = Buffer.from("jpg-image", "utf-8");
+      const pngImage = Buffer.from("png-image", "utf-8");
+
+      delegate.mockResolvedValue({ contentType: "image/jpeg", data: jpgImage });
+      const png = jest.fn();
+      (sharp as unknown as jest.Mock).mockReturnValue({ png });
+      png.mockReturnValue({
+        toBuffer: () => Promise.resolve(pngImage),
+      });
+
+      const result = await cachingImageFetcher(dir.name, delegate)(url);
+
+      expect(result!.contentType).toEqual("image/png");
+      expect(result!.data).toEqual(pngImage);
+
+      expect(delegate).toHaveBeenCalledWith(url);
+      expect(fse.existsSync(cacheFile)).toEqual(true);
+      expect(fse.readFileSync(cacheFile)).toEqual(pngImage);
+    });
+  });
+
+  describe("when the image is already in the cache", () => {
+    it("should fetch the image from the cache and return it", async () => {
+      const dir = tmp.dirSync();
+      const cacheFile = path.join(dir.name, `${Md5.hashStr(url)}.png`);
+      const data = Buffer.from("foobar2", "utf-8");
+
+      fse.writeFileSync(cacheFile, data);
+
+      const result = await cachingImageFetcher(dir.name, delegate)(url);
+
+      expect(result!.contentType).toEqual("image/png");
+      expect(result!.data).toEqual(data);
+
+      expect(delegate).not.toHaveBeenCalled();
+    });
+  });
+
+  describe("when the delegate returns undefined", () => {
+    it("should return undefined", async () => {
+      const dir = tmp.dirSync();
+      const cacheFile = path.join(dir.name, `${Md5.hashStr(url)}.png`);
+
+      delegate.mockResolvedValue(undefined);
+
+      const result = await cachingImageFetcher(dir.name, delegate)(url);
+
+      expect(result).toBeUndefined();
+
+      expect(delegate).toHaveBeenCalledWith(url);
+      expect(fse.existsSync(cacheFile)).toEqual(false);
+    });
+  });
+});

tests/subsonic.test.ts

@@ -1,8 +1,6 @@
 import { Md5 } from "ts-md5/dist/md5";
 import { v4 as uuid } from "uuid";
-import tmp from "tmp";
-import fse from "fs-extra";
-import path from "path";
+
 import {  pipe } from "fp-ts/lib/function";
 import { option as O, taskEither as TE, task as T, either as E } from "fp-ts";
 
@@ -14,7 +12,6 @@ import {
   asGenre,
   appendMimeTypeToClientFor,
   asURLSearchParams,
-  cachingImageFetcher,
   asTrack,
   artistImageURN,
   images,
@@ -29,8 +26,6 @@ import {
 import axios from "axios";
 jest.mock("axios");
 
-import sharp from "sharp";
-jest.mock("sharp");
 
 import randomstring from "randomstring";
 jest.mock("randomstring");
@@ -172,74 +167,6 @@ describe("asURLSearchParams", () => {
   });
 });
 
-describe("cachingImageFetcher", () => {
-  const delegate = jest.fn();
-  const url = "http://test.example.com/someimage.jpg";
-
-  beforeEach(() => {
-    jest.clearAllMocks();
-    jest.resetAllMocks();
-  });
-
-  describe("when there is no image in the cache", () => {
-    it("should fetch the image from the source and then cache and return it", async () => {
-      const dir = tmp.dirSync();
-      const cacheFile = path.join(dir.name, `${Md5.hashStr(url)}.png`);
-      const jpgImage = Buffer.from("jpg-image", "utf-8");
-      const pngImage = Buffer.from("png-image", "utf-8");
-
-      delegate.mockResolvedValue({ contentType: "image/jpeg", data: jpgImage });
-      const png = jest.fn();
-      (sharp as unknown as jest.Mock).mockReturnValue({ png });
-      png.mockReturnValue({
-        toBuffer: () => Promise.resolve(pngImage),
-      });
-
-      const result = await cachingImageFetcher(dir.name, delegate)(url);
-
-      expect(result!.contentType).toEqual("image/png");
-      expect(result!.data).toEqual(pngImage);
-
-      expect(delegate).toHaveBeenCalledWith(url);
-      expect(fse.existsSync(cacheFile)).toEqual(true);
-      expect(fse.readFileSync(cacheFile)).toEqual(pngImage);
-    });
-  });
-
-  describe("when the image is already in the cache", () => {
-    it("should fetch the image from the cache and return it", async () => {
-      const dir = tmp.dirSync();
-      const cacheFile = path.join(dir.name, `${Md5.hashStr(url)}.png`);
-      const data = Buffer.from("foobar2", "utf-8");
-
-      fse.writeFileSync(cacheFile, data);
-
-      const result = await cachingImageFetcher(dir.name, delegate)(url);
-
-      expect(result!.contentType).toEqual("image/png");
-      expect(result!.data).toEqual(data);
-
-      expect(delegate).not.toHaveBeenCalled();
-    });
-  });
-
-  describe("when the delegate returns undefined", () => {
-    it("should return undefined", async () => {
-      const dir = tmp.dirSync();
-      const cacheFile = path.join(dir.name, `${Md5.hashStr(url)}.png`);
-
-      delegate.mockResolvedValue(undefined);
-
-      const result = await cachingImageFetcher(dir.name, delegate)(url);
-
-      expect(result).toBeUndefined();
-
-      expect(delegate).toHaveBeenCalledWith(url);
-      expect(fse.existsSync(cacheFile)).toEqual(false);
-    });
-  });
-});
-
 const ok = (data: string | object) => ({
   status: 200,
   data,