update

package.json

@@ -25,7 +25,7 @@
     "dev": "rollup --config --watch",
     "lint": "eslint src/ test/",
     "fix-lint": "eslint src/ test/ --fix",
-    "test": "mocha out/test/featureFlag.test.{js,cjs,mjs} --parallel"
+    "test": "mocha out/test/*.test.{js,cjs,mjs} --parallel"
   },
   "repository": {
     "type": "git",

src/AzureAppConfigurationImpl.ts

@@ -10,6 +10,7 @@ import {
     ListConfigurationSettingsOptions,
     featureFlagPrefix,
     isFeatureFlag,
+    isSecretReference,
     GetSnapshotOptions,
     GetSnapshotResponse,
     KnownSnapshotComposition
@@ -102,6 +103,9 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
     #ffRefreshInterval: number = DEFAULT_REFRESH_INTERVAL_IN_MS;
     #ffRefreshTimer: RefreshTimer;
 
+    // Key Vault references
+    #resolveSecretsInParallel: boolean = false;
+
     /**
      * Selectors of key-values obtained from @see AzureAppConfigurationOptions.selectors
      */
@@ -182,6 +186,10 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
             }
         }
 
+        if (options?.keyVaultOptions?.parallelSecretResolutionEnabled) {
+            this.#resolveSecretsInParallel = options.keyVaultOptions.parallelSecretResolutionEnabled;
+        }
+
         this.#adapters.push(new AzureKeyVaultKeyValueAdapter(options?.keyVaultOptions));
         this.#adapters.push(new JsonKeyValueAdapter());
     }
@@ -526,7 +534,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
      */
     async #loadSelectedAndWatchedKeyValues() {
         const keyValues: [key: string, value: unknown][] = [];
-        const loadedSettings = await this.#loadConfigurationSettings();
+        const loadedSettings: ConfigurationSetting[] = await this.#loadConfigurationSettings();
         if (this.#refreshEnabled && !this.#watchAll) {
             await this.#updateWatchedKeyValuesEtag(loadedSettings);
         }
@@ -536,11 +544,25 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
             this.#aiConfigurationTracing.reset();
         }
 
-        // adapt configuration settings to key-values
+        const secretResolutionPromises: Promise<void>[] = [];
         for (const setting of loadedSettings) {
+            if (this.#resolveSecretsInParallel && isSecretReference(setting)) {
+                // secret references are resolved asynchronously to improve performance
+                const secretResolutionPromise = this.#processKeyValue(setting)
+                    .then(([key, value]) => {
+                        keyValues.push([key, value]);
+                    });
+                secretResolutionPromises.push(secretResolutionPromise);
+                continue;
+            }
+            // 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);
+        }
 
         this.#clearLoadedKeyValues(); // clear existing key-values in case of configuration setting deletion
         for (const [k, v] of keyValues) {
@@ -585,7 +607,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
      */
     async #loadFeatureFlags() {
         const loadFeatureFlag = true;
-        const featureFlagSettings = await this.#loadConfigurationSettings(loadFeatureFlag);
+        const featureFlagSettings: ConfigurationSetting[] = await this.#loadConfigurationSettings(loadFeatureFlag);
 
         if (this.#requestTracingEnabled && this.#featureFlagTracing !== undefined) {
             // Reset old feature flag tracing in order to track the information present in the current response from server.

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");
+    });
 });

test/load.test.ts

@@ -126,7 +126,7 @@ describe("load", function () {
         const connectionString = createMockedConnectionString();
         return expect(load(connectionString, {
             selectors: [{
-                labelFilter: "\0" 
+                labelFilter: "\0"
             }]
         })).eventually.rejectedWith("Key filter cannot be null or empty.");
     });
@@ -136,7 +136,7 @@ describe("load", function () {
         return expect(load(connectionString, {
             selectors: [{
                 snapshotName: "Test",
-                labelFilter: "\0" 
+                labelFilter: "\0"
             }]
         })).eventually.rejectedWith("Key or label filter should not be used for a snapshot.");
     });