From af636870d44bf1436ed3e91f92af03cf1f3218ed Mon Sep 17 00:00:00 2001
From: Nick O'Leary <nick.oleary@gmail.com>
Date: Tue, 6 Oct 2020 15:42:52 +0100
Subject: [PATCH] Add better error message if context file gets corrupted

---
 .../lib/nodes/context/localfilesystem.js      | 27 ++++++++++++-------
 .../runtime/locales/en-US/runtime.json        |  1 +
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/packages/node_modules/@node-red/runtime/lib/nodes/context/localfilesystem.js b/packages/node_modules/@node-red/runtime/lib/nodes/context/localfilesystem.js
index 9755681d8..ef499f0f9 100644
--- a/packages/node_modules/@node-red/runtime/lib/nodes/context/localfilesystem.js
+++ b/packages/node_modules/@node-red/runtime/lib/nodes/context/localfilesystem.js
@@ -137,16 +137,15 @@ function stringify(value) {
     return { json: result, circular: hasCircular };
 }
 
-
-function writeFileAtomic(storagePath, content) {
+async function writeFileAtomic(storagePath, content) {
     // To protect against file corruption, write to a tmp file first and then
     // rename to the destination file
     let finalFile = storagePath + ".json";
     let tmpFile = finalFile + "."+Date.now()+".tmp";
-    return fs.outputFile(tmpFile, content, "utf8").then(function() {
-        return fs.rename(tmpFile,finalFile);
-    })
+    await fs.outputFile(tmpFile, content, "utf8");
+    return fs.rename(tmpFile,finalFile);
 }
+
 function LocalFileSystem(config){
     this.config = config;
     this.storageBaseDir = getBasePath(this.config);
@@ -169,6 +168,7 @@ LocalFileSystem.prototype.open = function(){
     if (this.cache) {
         var scopes = [];
         var promises = [];
+        var contextFiles = [];
         return listFiles(self.storageBaseDir).then(function(files) {
             files.forEach(function(file) {
                 var parts = file.split(path.sep);
@@ -179,15 +179,22 @@ LocalFileSystem.prototype.open = function(){
                 } else {
                     scopes.push(parts[1].substring(0,parts[1].length-5)+":"+parts[0]);
                 }
-                promises.push(loadFile(path.join(self.storageBaseDir,file)));
+                let contextFile = path.join(self.storageBaseDir,file);
+                contextFiles.push(contextFile)
+                promises.push(loadFile(contextFile));
             })
             return Promise.all(promises);
         }).then(function(res) {
             scopes.forEach(function(scope,i) {
-                var data = res[i]?JSON.parse(res[i]):{};
-                Object.keys(data).forEach(function(key) {
-                    self.cache.set(scope,key,data[key]);
-                })
+                try {
+                    var data = res[i]?JSON.parse(res[i]):{};
+                    Object.keys(data).forEach(function(key) {
+                        self.cache.set(scope,key,data[key]);
+                    })
+                } catch(err) {
+                    let error = new Error(log._("context.localfilesystem.invalid-json",{file: contextFiles[i]}))
+                    throw error;
+                }
             });
         }).catch(function(err){
             if(err.code == 'ENOENT') {
diff --git a/packages/node_modules/@node-red/runtime/locales/en-US/runtime.json b/packages/node_modules/@node-red/runtime/locales/en-US/runtime.json
index 3047295de..bc866e09e 100644
--- a/packages/node_modules/@node-red/runtime/locales/en-US/runtime.json
+++ b/packages/node_modules/@node-red/runtime/locales/en-US/runtime.json
@@ -176,6 +176,7 @@
         "error-invalid-default-module": "Default context store unknown: '__storage__'",
         "unknown-store": "Unknown context store '__name__' specified. Using default store.",
         "localfilesystem": {
+            "invalid-json": "Invalid JSON in context file '__file__'",
             "error-circular": "Context __scope__ contains a circular reference that cannot be persisted",
             "error-write": "Error writing context: __message__"
         }