From ff492811230e7e8b39fd4da70951d2babcb27108 Mon Sep 17 00:00:00 2001
From: Lukasz Ostrowski <lukasz.ostrowski@saleor.io>
Date: Mon, 24 Oct 2022 16:11:15 +0200
Subject: [PATCH] Change behavior when FileAPL reads file that doesnt exist to
 fallback value (#96)

---
 src/APL/file-apl.test.ts | 25 ++++++++-----------------
 src/APL/file-apl.ts      | 26 +++++++++++++++++---------
 2 files changed, 25 insertions(+), 26 deletions(-)

diff --git a/src/APL/file-apl.test.ts b/src/APL/file-apl.test.ts
index 70eee80..9a02659 100644
--- a/src/APL/file-apl.test.ts
+++ b/src/APL/file-apl.test.ts
@@ -15,18 +15,14 @@ describe("APL", () => {
 
   describe("FileAPL", () => {
     describe("get", () => {
-      it("Should throw error when JSON parse fails", async () => {
-        vi.spyOn(fsPromises, "access").mockResolvedValue();
+      it("Should fallback to 'undefined' if parsing fail fails", async () => {
         vi.spyOn(fsPromises, "readFile").mockResolvedValue("Not a valid JSON");
 
         const apl = new FileAPL();
-        await expect(apl.get(stubAuthData.domain)).rejects.toThrow(
-          "File APL could not read auth data from the .saleor-app-auth.json file"
-        );
+        await expect(apl.get(stubAuthData.domain)).resolves.toBe(undefined);
       });
 
       it("Returns auth data for existing domain", async () => {
-        vi.spyOn(fsPromises, "access").mockResolvedValue();
         vi.spyOn(fsPromises, "readFile").mockResolvedValue(JSON.stringify(stubAuthData));
 
         const apl = new FileAPL();
@@ -35,7 +31,6 @@ describe("APL", () => {
       });
 
       it("Returns undefined for unknown domain", async () => {
-        vi.spyOn(fsPromises, "access").mockResolvedValue();
         vi.spyOn(fsPromises, "readFile").mockResolvedValue(JSON.stringify(stubAuthData));
 
         const apl = new FileAPL();
@@ -57,21 +52,20 @@ describe("APL", () => {
         );
         expect(spyWriteFile).toBeCalledWith(".saleor-app-auth.json", JSON.stringify(stubAuthData));
       });
-    });
 
-    it("Successfully save to file", async () => {
-      const spyWriteFile = vi.spyOn(fsPromises, "writeFile").mockResolvedValue();
+      it("Successfully save to file", async () => {
+        const spyWriteFile = vi.spyOn(fsPromises, "writeFile").mockResolvedValue();
 
-      const apl = new FileAPL();
+        const apl = new FileAPL();
 
-      await expect(apl.set(stubAuthData));
+        await expect(apl.set(stubAuthData));
 
-      expect(spyWriteFile).toBeCalledWith(".saleor-app-auth.json", JSON.stringify(stubAuthData));
+        expect(spyWriteFile).toBeCalledWith(".saleor-app-auth.json", JSON.stringify(stubAuthData));
+      });
     });
 
     describe("delete", () => {
       it("Should override file when called with known domain", async () => {
-        vi.spyOn(fsPromises, "access").mockResolvedValue();
         vi.spyOn(fsPromises, "readFile").mockResolvedValue(JSON.stringify(stubAuthData));
         const spyWriteFile = vi.spyOn(fsPromises, "writeFile").mockResolvedValue();
 
@@ -83,7 +77,6 @@ describe("APL", () => {
       });
 
       it("Should not delete data when called with unknown domain", async () => {
-        vi.spyOn(fsPromises, "access").mockResolvedValue();
         vi.spyOn(fsPromises, "readFile").mockResolvedValue(JSON.stringify(stubAuthData));
 
         const spyWriteFile = vi.spyOn(fsPromises, "writeFile").mockResolvedValue();
@@ -98,7 +91,6 @@ describe("APL", () => {
 
     describe("getAll", () => {
       it("Should return list with one item when auth data are existing", async () => {
-        vi.spyOn(fsPromises, "access").mockResolvedValue();
         vi.spyOn(fsPromises, "readFile").mockResolvedValue(JSON.stringify(stubAuthData));
 
         const apl = new FileAPL();
@@ -107,7 +99,6 @@ describe("APL", () => {
       });
 
       it("Should return empty list when auth data are empty", async () => {
-        vi.spyOn(fsPromises, "access").mockResolvedValue();
         vi.spyOn(fsPromises, "readFile").mockResolvedValue("{}");
 
         const apl = new FileAPL();
diff --git a/src/APL/file-apl.ts b/src/APL/file-apl.ts
index f6f5220..75b452a 100644
--- a/src/APL/file-apl.ts
+++ b/src/APL/file-apl.ts
@@ -31,38 +31,46 @@ export class FileAPL implements APL {
   /**
    * Load auth data from a file and return it as AuthData format.
    * In case of incomplete or invalid data, return `undefined`.
-   *
-   * @param {string} fileName
    */
   private async loadDataFromFile(): Promise<AuthData | undefined> {
-    debug(`Load auth data from the ${this.fileName} file`);
+    debug(`Will try to load auth data from the ${this.fileName} file`);
     let parsedData: Record<string, string> = {};
+
     try {
-      await fsPromises.access(this.fileName);
       parsedData = JSON.parse(await fsPromises.readFile(this.fileName, "utf-8"));
+      debug("%s read successfully", this.fileName);
     } catch (err) {
       debug(`Could not read auth data from the ${this.fileName} file`, err);
-      throw new Error(`File APL could not read auth data from the ${this.fileName} file`);
+      debug(
+        "Maybe apl.get() was called before app was registered. Returning empty, fallback data (undefined)"
+      );
+
+      return undefined;
     }
+
     const { token, domain } = parsedData;
+
     if (token && domain) {
+      debug("Token and domain found, returning values: %s, %s", domain, `${token[0]}***`);
       return { token, domain };
     }
+
     return undefined;
   }
 
   /**
    * Save auth data to file.
    * When `authData` argument is empty, will overwrite file with empty values.
-   *
-   * @param {string} fileName
-   * @param {AuthData} [authData]
    */
   private async saveDataToFile(authData?: AuthData) {
-    debug(`Save auth data to the ${this.fileName} file`);
+    debug(`Trying to save auth data to the ${this.fileName} file`);
+
     const newData = authData ? JSON.stringify(authData) : "{}";
+
     try {
       await fsPromises.writeFile(this.fileName, newData);
+
+      debug("Successfully written file %", this.fileName);
     } catch (err) {
       debug(`Could not save auth data to the ${this.fileName} file`, err);
       throw new Error("File APL was unable to save auth data");