Throw error when config.json contains invalid JSON or is inaccessible

README.md

@@ -97,7 +97,7 @@ npm ci
 ```
 
 ### Configuration
-You can customize the application settings via a configuration file. By default, this configuration file resides in `config/config.json`. However, it is possible to adjust this path via the `CONFIG_FILE` environment variable. Note that the given path has to be either absolute (i.e. starting with `/`) or relative to the `config/` folder (i.e. it defaults to `./config.json`). **Note** that the path to the configuration file needs to be valid and writable because a `namespace` key will be generated and written to the file if it doesn't currently exist.
+You can customize the application settings via a configuration file. By default, this configuration file resides in `config/config.json`. However, it is possible to adjust this path via the `CONFIG_FILE` environment variable. Note that the given path has to be either absolute (i.e. starting with `/`) or relative to the `config/` folder (i.e. it defaults to `./config.json`). **Note** that the path to the configuration file needs to be valid and writable because a `namespace` key will be generated and written to the file if it doesn't currently exist. **Note** that if the file exists and contains invalid JSON data, JSKOS Server will refuse to start.
 
 Currently, there are only two environment variables:
 - `NODE_ENV` - either `development` (default) or `production`; currently, the only difference is that in `production`, HTTPS URIs are forced for entities created on POST requests.

config/index.js

@@ -49,7 +49,8 @@ let configUser = {}
 try {
   configUser = JSON.parse(fs.readFileSync(configFilePath))
 } catch(error) {
-  console.warn(`Warning: Could not load configuration file from ${configFilePath}. The application might not behave as expected.`)
+  console.error(`Warning: Could not load configuration file from ${configFilePath}. Please check whether it is valid JSON and restart the application.`)
+  process.exit(1)
 }
 if (env == "test") {
   configUser = _.pick(configUser, ["mongo"])