From 732a97ba0cce84352e6fc691195700c0fac6bd27 Mon Sep 17 00:00:00 2001
From: Koen Kanters <koenkanters94@gmail.com>
Date: Thu, 3 Oct 2019 20:06:31 +0200
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20write=20to=20configuration.yaml?=
 =?UTF-8?q?=20when=20it=20didn=E2=80=99t=20change.=20https://github.com/Ko?=
 =?UTF-8?q?enkk/zigbee2mqtt/issues/2071?=
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---
 lib/util/settings.js    |  6 +++---
 lib/util/yaml.js        | 10 +++++++---
 package.json            |  1 +
 test/controller.test.js |  7 +++++++
 test/settings.test.js   | 11 +++++++++++
 test/stub/data.js       |  4 ++--
 6 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/lib/util/settings.js b/lib/util/settings.js
index 03671472fa..bed07bf3ac 100644
--- a/lib/util/settings.js
+++ b/lib/util/settings.js
@@ -244,16 +244,16 @@ function write() {
     // Read settings to check if we have to split devices/groups into separate file.
     const actual = yaml.read(file);
     if (typeof actual.devices === 'string') {
-        yaml.write(data.joinPath(actual.devices), settings.devices);
+        yaml.writeIfChanged(data.joinPath(actual.devices), settings.devices);
         toWrite.devices = actual.devices;
     }
 
     if (typeof actual.groups === 'string') {
-        yaml.write(data.joinPath(actual.groups), settings.groups);
+        yaml.writeIfChanged(data.joinPath(actual.groups), settings.groups);
         toWrite.groups = actual.groups;
     }
 
-    yaml.write(file, toWrite);
+    yaml.writeIfChanged(file, toWrite);
 
     _settings = read();
     _settingsWithDefaults = objectAssignDeep.noMutate(defaults, get());
diff --git a/lib/util/yaml.js b/lib/util/yaml.js
index 9d2ab8a41d..a3a64c1c1c 100644
--- a/lib/util/yaml.js
+++ b/lib/util/yaml.js
@@ -1,5 +1,6 @@
 const yaml = require('js-yaml');
 const fs = require('fs');
+const equals = require('fast-deep-equal');
 
 function read(file) {
     try {
@@ -25,8 +26,11 @@ function readIfExists(file) {
     return fs.existsSync(file) ? read(file) : null;
 }
 
-function write(file, content) {
-    fs.writeFileSync(file, yaml.safeDump(content));
+function writeIfChanged(file, content) {
+    const before = readIfExists(file);
+    if (!equals(before, content)) {
+        fs.writeFileSync(file, yaml.safeDump(content));
+    }
 }
 
-module.exports = {read, readIfExists, write};
+module.exports = {read, readIfExists, writeIfChanged};
diff --git a/package.json b/package.json
index a6381b822c..03b4a2d18c 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
   "dependencies": {
     "ajv": "*",
     "debounce": "*",
+    "fast-deep-equal": "*",
     "git-last-commit": "*",
     "js-yaml": "*",
     "mkdir-recursive": "*",
diff --git a/test/controller.test.js b/test/controller.test.js
index b84d2d9e45..7bb05838cd 100644
--- a/test/controller.test.js
+++ b/test/controller.test.js
@@ -380,4 +380,11 @@ describe('Controller', () => {
         await flushPromises();
         expect(MQTT.publish).toHaveBeenCalledTimes(0);
     });
+
+    it('Should start when state is corrupted', async () => {
+        fs.writeFileSync(path.join(data.mockDir, 'state.json'), 'corrupted');
+        await controller.start();
+        await flushPromises();
+        expect(controller.state.state).toStrictEqual({});
+    });
 });
diff --git a/test/settings.test.js b/test/settings.test.js
index e3af2b0356..7d8d0e0484 100644
--- a/test/settings.test.js
+++ b/test/settings.test.js
@@ -463,4 +463,15 @@ describe('Settings', () => {
             settings.changeFriendlyName('myname1', 'myname');
         }).toThrowError(`friendly_name 'myname' is already in use`);
     });
+
+    it('Shouldnt write to configuration.yaml when there are no changes in it', () => {
+        const contentConfiguration = {devices: 'devices.yaml'};
+        const contentDevices = {};
+        write(configurationFile, contentConfiguration);
+        const before = fs.statSync(configurationFile).mtimeMs;
+        write(devicesFile, contentDevices);
+        settings.addDevice('0x1234');
+        const after = fs.statSync(configurationFile).mtimeMs;
+        expect(before).toBe(after);
+    });
 });
diff --git a/test/stub/data.js b/test/stub/data.js
index de867d5942..f764802327 100644
--- a/test/stub/data.js
+++ b/test/stub/data.js
@@ -132,11 +132,11 @@ function writeDefaultConfiguration() {
         }
     };
 
-    yaml.write(path.join(mockDir, 'configuration.yaml'), config);
+    yaml.writeIfChanged(path.join(mockDir, 'configuration.yaml'), config);
 }
 
 function writeEmptyState() {
-    yaml.write(path.join(mockDir, 'state.json'), JSON.stringify({}));
+    fs.writeFileSync(path.join(mockDir, 'state.json'), JSON.stringify({}));
 }
 
 function writeDefaultState() {