Retain public SDK constructor

javascript-sdk/src/sdk.ts

@@ -22,36 +22,51 @@ function generateCanaryWord(length = 8): string {
 }
 
 export default class RebuffSdk implements Rebuff {
-  private vectorStore: VectorStore;
-  private strategies: Record<string, Strategy>;
+  private sdkConfig: SdkConfig;
+  private vectorStore: VectorStore | undefined;
+  private strategies: Record<string, Strategy> | undefined;
   private defaultStrategy: string;
 
-  private constructor(strategies: Record<string, Strategy>, vectorStore: VectorStore) {
-    this.vectorStore = vectorStore;
-    this.strategies = strategies;
+  /**
+   * @deprecated Use `RebuffSdk.init` instead.
+   */
+  constructor(config: SdkConfig) {
+    // We're keeping this constructor for backwards compatibility. In the future, we can make it private and
+    // simplify this class quite a bit.
+
+    this.sdkConfig = config;
     this.defaultStrategy = "standard";
   }
 
   public static async init(config: SdkConfig): Promise<RebuffSdk> {
-    const vectorStore = await initVectorStore(config);
+    const sdk = new RebuffSdk(config);
+    sdk.vectorStore = await initVectorStore(config);
+    sdk.strategies = await sdk.getStrategies();
+    return sdk;
+  }
+
+  private async getStrategies(): Promise<Record<string, Strategy>> {
+    if (this.strategies) {
+      return this.strategies;
+    }
     const openai = {
-      conn: getOpenAIInstance(config.openai.apikey),
-      model: config.openai.model || "gpt-3.5-turbo",
+      conn: getOpenAIInstance(this.sdkConfig.openai.apikey),
+      model: this.sdkConfig.openai.model || "gpt-3.5-turbo",
     };
     const heuristicScoreThreshold = 0.75;
     const vectorScoreThreshold = 0.9;
     const openaiScoreThreshold = 0.9;
-    const strategies = {
+    this.strategies = {
       // For now, this is the only strategy.
       "standard": {
         tactics: [
           new Heuristic(heuristicScoreThreshold),
-          new Vector(vectorScoreThreshold, vectorStore),
+          new Vector(vectorScoreThreshold, await this.getVectorStore()),
           new OpenAI(openaiScoreThreshold, openai.model, openai.conn),
         ]
       },
     };
-    return new RebuffSdk(strategies, vectorStore);
+    return this.strategies;
   }
 
   async detectInjection({
@@ -69,9 +84,10 @@ export default class RebuffSdk implements Rebuff {
       throw new RebuffError("userInput is required");
     }
 
+    const strategies = await this.getStrategies();
     let injectionDetected = false;
     let tacticResults: TacticResult[] = [];
-    for (const tactic of this.strategies[this.defaultStrategy].tactics) {
+    for (const tactic of strategies[this.defaultStrategy].tactics) {
       const tacticOverride = tacticOverrides.find(t => t.name === tactic.name);
       if (tacticOverride && tacticOverride.run === false) {
         continue;
@@ -124,11 +140,19 @@ export default class RebuffSdk implements Rebuff {
     return false;
   }
 
+  async getVectorStore(): Promise<VectorStore> {
+    if (this.vectorStore) {
+      return this.vectorStore;
+    }
+    this.vectorStore = await initVectorStore(this.sdkConfig);
+    return this.vectorStore
+  }
+
   async logLeakage(
     input: string,
     metaData: Record<string, string>
   ): Promise<void> {
-    await this.vectorStore.addDocuments([new Document({
+    await (await this.getVectorStore()).addDocuments([new Document({
       metadata: metaData,
       pageContent: input,
     })]);