From 34b0196c0f92316c4c58a776bb9d6c5e34780160 Mon Sep 17 00:00:00 2001
From: Naz <nazargargol@gmail.com>
Date: Thu, 18 Nov 2021 16:01:57 +0400
Subject: [PATCH] Added writeDisabled flag to URL file cache

refs https://github.com/TryGhost/Toolbox/issues/135

- Allows to turn off overwriting urls/resources JSON file caches on testing environment. This is needed to have predictable state when running multiple test suites that stop the Ghost process and try to persiste URL cache.
---
 core/server/services/url/LocalFileCache.js    |  8 ++++-
 core/server/services/url/index.js             |  9 +++--
 .../services/url/LocalFileCache.test.js       | 33 +++++++++++++++++++
 3 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/core/server/services/url/LocalFileCache.js b/core/server/services/url/LocalFileCache.js
index cbb46255e3..70eb5aacb6 100644
--- a/core/server/services/url/LocalFileCache.js
+++ b/core/server/services/url/LocalFileCache.js
@@ -5,8 +5,9 @@ class LocalFileCache {
     /**
      * @param {Object} options
      * @param {String} options.storagePath - cached storage path
+     * @param {Boolean} options.writeDisabled - controls if cache can write
      */
-    constructor({storagePath}) {
+    constructor({storagePath, writeDisabled}) {
         const urlsStoragePath = path.join(storagePath, 'urls.json');
         const resourcesCachePath = path.join(storagePath, 'resources.json');
 
@@ -14,6 +15,7 @@ class LocalFileCache {
             urls: urlsStoragePath,
             resources: resourcesCachePath
         };
+        this.writeDisabled = writeDisabled;
     }
 
     /**
@@ -62,6 +64,10 @@ class LocalFileCache {
      * @returns {Promise<Object>}
      */
     async write(type, data) {
+        if (this.writeDisabled) {
+            return null;
+        }
+
         return fs.writeFile(this.storagePaths[type], JSON.stringify(data, null, 4));
     }
 }
diff --git a/core/server/services/url/index.js b/core/server/services/url/index.js
index a7e8805930..5abff73f18 100644
--- a/core/server/services/url/index.js
+++ b/core/server/services/url/index.js
@@ -5,16 +5,21 @@ const UrlService = require('./UrlService');
 // NOTE: instead of a path we could give UrlService a "data-resolver" of some sort
 //       so it doesn't have to contain the logic to read data at all. This would be
 //       a possible improvement in the future
-
+let writeDisabled = false;
 let storagePath = config.getContentPath('data');
 
 // TODO: remove this hack in favor of loading from the content path when it's possible to do so
 //       by mocking content folders in pre-boot phase
 if (process.env.NODE_ENV.match(/^testing/)){
     storagePath = config.get('paths').urlCache;
+
+    // NOTE: prevents test suites from overwriting cache fixtures.
+    //       A better solution would be injecting a different implementation of the
+    //       cache based on the environment, this approach should do the trick for now
+    writeDisabled = true;
 }
 
-const cache = new LocalFileCache({storagePath});
+const cache = new LocalFileCache({storagePath, writeDisabled});
 const urlService = new UrlService({cache});
 
 // Singleton
diff --git a/test/unit/frontend/services/url/LocalFileCache.test.js b/test/unit/frontend/services/url/LocalFileCache.test.js
index 96a15131a4..d53a4ee79b 100644
--- a/test/unit/frontend/services/url/LocalFileCache.test.js
+++ b/test/unit/frontend/services/url/LocalFileCache.test.js
@@ -52,4 +52,37 @@ describe('Unit: services/url/LocalFileCache', function () {
             should.equal(cachedUrls, null);
         });
     });
+
+    describe('write', function () {
+        it('writes to the file system by type', async function () {
+            const storagePath = '/tmp/url-cache/';
+            const writeFileStub = sinon.stub(fs, 'writeFile')
+                .withArgs(`${storagePath}urls.json`)
+                .resolves(true);
+
+            const localFileCache = new LocalFileCache({storagePath});
+
+            const result = await localFileCache.write('urls', {data: 'test'});
+
+            result.should.equal(true);
+            writeFileStub.called.should.equal(true);
+        });
+
+        it('does not write to the file system is writes are disabled', async function () {
+            const storagePath = '/tmp/url-cache/';
+            const writeFileStub = sinon.stub(fs, 'writeFile')
+                .withArgs(`${storagePath}urls.json`)
+                .resolves(true);
+
+            const localFileCache = new LocalFileCache({
+                storagePath,
+                writeDisabled: true
+            });
+
+            const result = await localFileCache.write('urls', {data: 'test'});
+
+            should.equal(result, null);
+            writeFileStub.called.should.equal(false);
+        });
+    });
 });