Refactor standalone-cache.test.js to avoid relying on 'flatted' (#3940)

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> Which issue, if any, is this issue related to?

Closes #3786

> Is there anything in the PR that needs further explanation?

Use `file-entry-cache#createFromFile` to create another instance of the cache, so that we can access to the cache without relying on the `flatted` which is the dependency of `file-entry-cache`

lib/__tests__/standalone-cache.test.js

@@ -6,14 +6,11 @@ const standalone = require("../standalone");
 const fixturesPath = path.join(__dirname, "fixtures");
 const fs = require("fs");
 const pify = require("pify");
-const readFile = pify(fs.readFile);
 const unlink = pify(fs.unlink);
 const cpFile = require("cp-file");
 const fileExists = require("file-exists-promise");
-// As 'file-entry-cache' use 'flatted' to create the cache,
-// need use this package to parse the content
-// eslint-disable-next-line node/no-extraneous-require
-const { parse } = require("flatted/cjs");
+
+const fCache = require("file-entry-cache");
 
 const cwd = process.cwd();
 const invalidFile = path.join(fixturesPath, "empty-block.css");
@@ -58,20 +55,16 @@ describe("standalone cache", () => {
 
   it("cache file is created at $CWD/.stylelintcache", () => {
     // Ensure cache file exists
-    return fileExists(expectedCacheFilePath)
-      .then(isFileExist => {
-        expect(!!isFileExist).toBe(true);
+    return fileExists(expectedCacheFilePath).then(isFileExist => {
+      expect(!!isFileExist).toBe(true);
 
-        return readFile(expectedCacheFilePath, "utf8");
-      })
-      .then(fileContents => {
-        return parse(fileContents);
-      })
-      .then(cacheFile => {
-        // Ensure cache file contains only linted css file
-        expect(typeof cacheFile[validFile] === "object").toBe(true);
-        expect(typeof cacheFile[newFileDest] === "undefined").toBe(true);
-      });
+      const fileCache = fCache.createFromFile(expectedCacheFilePath);
+      const { cache } = fileCache;
+
+      // Ensure cache file contains only linted css file
+      expect(typeof cache.getKey(validFile) === "object").toBe(true);
+      expect(typeof cache.getKey(newFileDest) === "undefined").toBe(true);
+    });
   });
 
   it("only changed files are linted", () => {
@@ -93,15 +86,11 @@ describe("standalone cache", () => {
         expect(isValidFileLinted).toBe(false);
         expect(isNewFileLinted).toBe(true);
 
-        // Ensure cache file contains linted css files
-        return readFile(expectedCacheFilePath, "utf8");
-      })
-      .then(fileContents => {
-        return parse(fileContents);
-      })
-      .then(cachedFiles => {
-        expect(typeof cachedFiles[validFile] === "object").toBe(true);
-        expect(typeof cachedFiles[newFileDest] === "object").toBe(true);
+        const fileCache = fCache.createFromFile(expectedCacheFilePath);
+        const { cache } = fileCache;
+
+        expect(typeof cache.getKey(validFile) === "object").toBe(true);
+        expect(typeof cache.getKey(newFileDest) === "object").toBe(true);
       });
   });
 
@@ -148,15 +137,11 @@ describe("standalone cache", () => {
         expect(isValidFileLinted).toBe(false);
         expect(isInvalidFileLinted).toBe(true);
 
-        // Ensure cache file doesn't contain invalid file
-        return readFile(expectedCacheFilePath, "utf8");
-      })
-      .then(fileContents => {
-        return parse(fileContents);
-      })
-      .then(cachedFiles => {
-        expect(typeof cachedFiles[validFile] === "object").toBe(true);
-        expect(typeof cachedFiles[newFileDest] === "undefined").toBe(true);
+        const fileCache = fCache.createFromFile(expectedCacheFilePath);
+        const { cache } = fileCache;
+
+        expect(typeof cache.getKey(validFile) === "object").toBe(true);
+        expect(typeof cache.getKey(newFileDest) === "undefined").toBe(true);
       });
   });
   it("files with syntax errors are not cached", () => {
@@ -166,13 +151,11 @@ describe("standalone cache", () => {
         return standalone(getConfig());
       })
       .then(() => {
-        return readFile(expectedCacheFilePath, "utf8");
-      })
-      .then(fileContents => {
-        const cachedFiles = parse(fileContents);
+        const fileCache = fCache.createFromFile(expectedCacheFilePath);
+        const { cache } = fileCache;
 
-        expect(typeof cachedFiles[validFile] === "object").toBe(true);
-        expect(typeof cachedFiles[newFileDest] === "undefined").toBe(true);
+        expect(typeof cache.getKey(validFile) === "object").toBe(true);
+        expect(typeof cache.getKey(newFileDest) === "undefined").toBe(true);
       });
   });
   it("cache file is removed when cache is disabled", () => {
@@ -257,14 +240,10 @@ describe("standalone cache uses cacheLocation", () => {
       .then(fileStats => {
         expect(!!fileStats).toBe(true);
 
-        // Ensure cache file contains cached entity
-        return readFile(cacheLocationFile, "utf8");
-      })
-      .then(fileContents => {
-        return parse(fileContents);
-      })
-      .then(cacheFile => {
-        expect(typeof cacheFile[validFile] === "object").toBe(true);
+        const fileCache = fCache.createFromFile(cacheLocationFile);
+        const { cache } = fileCache;
+
+        expect(typeof cache.getKey(validFile) === "object").toBe(true);
       });
   });
   it("cacheLocation is a directory", () => {
@@ -280,14 +259,10 @@ describe("standalone cache uses cacheLocation", () => {
         // Ensure cache file is created
         expect(!!cacheFileStats).toBe(true);
 
-        // Ensure cache file contains cached entity
-        return readFile(expectedCacheFilePath, "utf8");
-      })
-      .then(fileContents => {
-        return parse(fileContents);
-      })
-      .then(cacheFile => {
-        expect(typeof cacheFile[validFile] === "object").toBe(true);
+        const fileCache = fCache.createFromFile(expectedCacheFilePath);
+        const { cache } = fileCache;
+
+        expect(typeof cache.getKey(validFile) === "object").toBe(true);
       });
   });
 });

package.json

@@ -45,7 +45,7 @@
     "cosmiconfig": "^5.0.0",
     "debug": "^4.0.0",
     "execall": "^1.0.0",
-    "file-entry-cache": "^4.0.0",
+    "file-entry-cache": "^5.0.1",
     "get-stdin": "^6.0.0",
     "global-modules": "^2.0.0",
     "globby": "^9.0.0",