Adds a ConfigManager to persist configuration (#115)

Stacked on #116

Signed-off-by: Tyler Smalley <tyler@tailscale.com>

package.json

@@ -314,7 +314,7 @@
     "package": "vsce package --allow-star-activation",
     "precommit": "lint-staged",
     "prepare": "husky install",
-    "test": "vitest --passWithNoTests",
+    "test": "vitest",
     "vscode:prepublish": "(yarn run bundle-js & pid1=$!; yarn run bundle-go & pid2=$!; wait $pid1 || exit 1; wait $pid2 || exit 1)",
     "watch": "webpack serve"
   },

src/config-manager.test.ts

@@ -0,0 +1,46 @@
+import * as vscode from 'vscode';
+import * as fs from 'fs';
+import * as path from 'path';
+import { test, expect, beforeEach } from 'vitest';
+import { ConfigManager } from './config-manager';
+
+const extensionContext = {
+  globalStoragePath: '/tmp/vscode-tailscale',
+} as vscode.ExtensionContext;
+
+const configPath = path.join(extensionContext.globalStoragePath, 'config.json');
+
+beforeEach(() => {
+  if (fs.existsSync(configPath)) {
+    fs.unlinkSync(configPath);
+  }
+});
+
+test('withContext will create directory if it does not exist', () => {
+  fs.rmSync(extensionContext.globalStoragePath, { recursive: true, force: true });
+  expect(fs.existsSync(extensionContext.globalStoragePath)).toBe(false);
+
+  ConfigManager.withContext(extensionContext);
+  expect(fs.existsSync(extensionContext.globalStoragePath)).toBe(true);
+});
+
+test('withContext returns an initialized ConfigManager', () => {
+  const cm = ConfigManager.withContext(extensionContext);
+  expect(cm.configPath).toBe(configPath);
+});
+
+test('set persists config to disk', () => {
+  const cm = new ConfigManager(configPath);
+  const hosts = {
+    'host-1': {
+      user: 'foo',
+      rootDir: '/',
+    },
+  };
+
+  cm.set('hosts', hosts);
+  expect(cm.get('hosts')).toEqual(hosts);
+
+  const f = fs.readFileSync(configPath, 'utf8');
+  expect(JSON.parse(f)).toEqual({ hosts });
+});

src/config-manager.ts

@@ -0,0 +1,49 @@
+import * as vscode from 'vscode';
+import * as fs from 'fs';
+import * as path from 'path';
+
+interface Host {
+  user: string;
+  rootDir: string;
+}
+
+interface Config {
+  defaultHost?: Host;
+  hosts?: Record<string, Host>;
+}
+
+export class ConfigManager {
+  private config: Config;
+
+  constructor(public readonly configPath: string) {
+    if (fs.existsSync(this.configPath)) {
+      const rawData = fs.readFileSync(this.configPath, 'utf8');
+      this.config = JSON.parse(rawData);
+    } else {
+      this.config = {};
+    }
+  }
+
+  static withContext(context: vscode.ExtensionContext) {
+    const globalStoragePath = context.globalStoragePath;
+
+    if (!fs.existsSync(globalStoragePath)) {
+      fs.mkdirSync(globalStoragePath);
+    }
+
+    return new ConfigManager(path.join(globalStoragePath, 'config.json'));
+  }
+
+  get<K extends keyof Config>(key: K): Config[K] {
+    return this.config[key];
+  }
+
+  set<K extends keyof Config>(key: K, value: Config[K]) {
+    this.config[key] = value;
+    this.saveConfig();
+  }
+
+  private saveConfig() {
+    fs.writeFileSync(this.configPath, JSON.stringify(this.config, null, 2), 'utf8');
+  }
+}