add parallelSecretResolutionEnabled option

Author: zhiyuanliang-ms

src/AzureAppConfigurationImpl.ts

@@ -83,6 +83,9 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
     #ffRefreshInterval: number = DEFAULT_REFRESH_INTERVAL_IN_MS;
     #ffRefreshTimer: RefreshTimer;
 
+    // Key Vault references
+    #resolveSecretInParallel: boolean = false;
+
     /**
      * Selectors of key-values obtained from @see AzureAppConfigurationOptions.selectors
      */
@@ -163,6 +166,10 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
             }
         }
 
+        if (options?.keyVaultOptions?.parallelSecretResolutionEnabled) {
+            this.#resolveSecretInParallel = options.keyVaultOptions.parallelSecretResolutionEnabled;
+        }
+
         this.#adapters.push(new AzureKeyVaultKeyValueAdapter(options?.keyVaultOptions));
         this.#adapters.push(new JsonKeyValueAdapter());
     }
@@ -496,7 +503,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
 
         const secretResolutionPromises: Promise<void>[] = [];
         for (const setting of loadedSettings) {
-            if (isSecretReference(setting)) {
+            if (this.#resolveSecretInParallel && isSecretReference(setting)) {
                 // secret references are resolved asynchronously to improve performance
                 const secretResolutionPromise = this.#processKeyValue(setting)
                     .then(([key, value]) => {
@@ -508,9 +515,11 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
             // adapt configuration settings to key-values
             const [key, value] = await this.#processKeyValue(setting);
             keyValues.push([key, value]);
+        } 
+        if (secretResolutionPromises.length > 0) {
+            // wait for all secret resolution promises to be resolved
+            await Promise.all(secretResolutionPromises);
         }
-        // wait for all secret resolution promises to be resolved
-        await Promise.all(secretResolutionPromises);
 
         this.#clearLoadedKeyValues(); // clear existing key-values in case of configuration setting deletion
         for (const [k, v] of keyValues) {

src/keyvault/KeyVaultOptions.ts

@@ -32,4 +32,12 @@ export interface KeyVaultOptions {
      * @returns The secret value.
      */
     secretResolver?: (keyVaultReference: URL) => string | Promise<string>;
+
+    /**
+     * Specifies whether to resolve the secret value in parallel.
+     *
+     * @remarks
+     * If not specified, the default value is false.
+     */
+    parallelSecretResolutionEnabled?: boolean;
 }

test/keyvault.test.ts

@@ -127,4 +127,16 @@ describe("key vault reference", function () {
         expect(settings.get("TestKey")).eq("SecretValue");
         expect(settings.get("TestKey2")).eq("SecretValue2");
     });
+
+    it("should resolve key vault reference in parallel", async () => {
+        const settings = await load(createMockedConnectionString(), {
+            keyVaultOptions: {
+                credential: createMockedTokenCredential(),
+                parallelSecretResolutionEnabled: true
+            }
+        });
+        expect(settings).not.undefined;
+        expect(settings.get("TestKey")).eq("SecretValue");
+        expect(settings.get("TestKeyFixedVersion")).eq("OldSecretValue");
+    });
 });