Validate config before loading datastore

src/datastore/DataStore.ts

@@ -14,6 +14,7 @@ import CaptainConstants from '../utils/CaptainConstants'
 import CaptainEncryptor from '../utils/Encryptor'
 import Utils from '../utils/Utils'
 import AppsDataStore from './AppsDataStore'
+import validateConfigFile from './validateConfigFile'
 import ProDataStore from './ProDataStore'
 import ProjectsDataStore from './ProjectsDataStore'
 import RegistriesDataStore from './RegistriesDataStore'
@@ -69,11 +70,14 @@ class DataStore {
     private projectsDataStore: ProjectsDataStore
 
     constructor(namespace: string) {
+        const configPath = `${CaptainConstants.captainDataDirectory}/config-${namespace}.json`
+        validateConfigFile(configPath)
+
         const data = new Configstore(
             `captain-store-${namespace}`, // This value seems to be unused
             {},
             {
-                configPath: `${CaptainConstants.captainDataDirectory}/config-${namespace}.json`,
+                configPath,
             }
         )
 

src/datastore/validateConfigFile.ts

@@ -0,0 +1,15 @@
+import fs = require('fs-extra')
+
+export default function validateConfigFile(configPath: string): void {
+    if (!fs.pathExistsSync(configPath)) {
+        return
+    }
+
+    try {
+        fs.readJsonSync(configPath)
+    } catch {
+        throw new Error(
+            `Cannot load CapRover configuration from ${configPath}: the file contains malformed JSON. Fix the file or restore it from a backup before restarting CapRover.`
+        )
+    }
+}

tests/validateConfigFile.test.ts

@@ -0,0 +1,40 @@
+import fs = require('fs-extra')
+import os = require('os')
+import path = require('path')
+import validateConfigFile from '../src/datastore/validateConfigFile'
+
+describe('validateConfigFile', () => {
+    let temporaryDirectory: string
+    let configPath: string
+
+    beforeEach(() => {
+        temporaryDirectory = fs.mkdtempSync(
+            path.join(os.tmpdir(), 'caprover-config-')
+        )
+        configPath = path.join(temporaryDirectory, 'config-captain.json')
+    })
+
+    afterEach(() => {
+        fs.removeSync(temporaryDirectory)
+    })
+
+    test('rejects malformed JSON without modifying the file', () => {
+        const malformedConfig = '{"namespace":"captain",}'
+        fs.writeFileSync(configPath, malformedConfig)
+
+        expect(() => validateConfigFile(configPath)).toThrow(
+            'the file contains malformed JSON'
+        )
+        expect(fs.readFileSync(configPath, 'utf8')).toBe(malformedConfig)
+    })
+
+    test('accepts valid JSON', () => {
+        fs.writeJsonSync(configPath, { namespace: 'captain' })
+
+        expect(() => validateConfigFile(configPath)).not.toThrow()
+    })
+
+    test('accepts a missing config file for first-time setup', () => {
+        expect(() => validateConfigFile(configPath)).not.toThrow()
+    })
+})