fix bug that previous secret reference will override the same key loaded later when secret refresh is enabled

Author: zhiyuanliang-ms

src/appConfigurationImpl.ts

@@ -479,10 +479,12 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
      *                          If true, loads feature flag using the feature flag selectors;
      *                          If false, loads key-value using the key-value selectors. Defaults to false.
      */
-    async #loadConfigurationSettings(loadFeatureFlag: boolean = false): Promise<ConfigurationSetting[]> {
+    async #loadConfigurationSettings(loadFeatureFlag: boolean = false): Promise<Map<string, ConfigurationSetting>> {
         const selectors = loadFeatureFlag ? this.#ffSelectors : this.#kvSelectors;
         const funcToExecute = async (client) => {
-            const loadedSettings: ConfigurationSetting[] = [];
+            // Use a Map to deduplicate configuration settings by key. When multiple selectors return settings with the same key,
+            // the configuration setting loaded by the later selector in the iteration order will override the one from the earlier selector.
+            const loadedSettings: Map<string, ConfigurationSetting> = new Map<string, ConfigurationSetting>();
             // deep copy selectors to avoid modification if current client fails
             const selectorsToUpdate = JSON.parse(
                 JSON.stringify(selectors)
@@ -506,7 +508,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
                         pageEtags.push(page.etag ?? "");
                         for (const setting of page.items) {
                             if (loadFeatureFlag === isFeatureFlag(setting)) {
-                                loadedSettings.push(setting);
+                                loadedSettings.set(setting.key, setting);
                             }
                         }
                     }
@@ -528,7 +530,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
                     for await (const page of pageIterator) {
                         for (const setting of page.items) {
                             if (loadFeatureFlag === isFeatureFlag(setting)) {
-                                loadedSettings.push(setting);
+                                loadedSettings.set(setting.key, setting);
                             }
                         }
                     }
@@ -543,7 +545,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
             return loadedSettings;
         };
 
-        return await this.#executeWithFailoverPolicy(funcToExecute) as ConfigurationSetting[];
+        return await this.#executeWithFailoverPolicy(funcToExecute) as Map<string, ConfigurationSetting>;
     }
 
     /**
@@ -552,7 +554,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
     async #loadSelectedAndWatchedKeyValues() {
         this.#secretReferences = []; // clear all cached key vault reference configuration settings
         const keyValues: [key: string, value: unknown][] = [];
-        const loadedSettings: ConfigurationSetting[] = await this.#loadConfigurationSettings();
+        const loadedSettings: Map<string, ConfigurationSetting> = await this.#loadConfigurationSettings();
         if (this.#refreshEnabled && !this.#watchAll) {
             await this.#updateWatchedKeyValuesEtag(loadedSettings);
         }
@@ -562,7 +564,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
             this.#aiConfigurationTracing.reset();
         }
 
-        for (const setting of loadedSettings) {
+        for (const setting of loadedSettings.values()) {
             if (isSecretReference(setting)) {
                 this.#secretReferences.push(setting); // cache secret references for resolve/refresh secret separately
                 continue;
@@ -587,9 +589,10 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
     /**
      * Updates etag of watched settings from loaded data. If a watched setting is not covered by any selector, a request will be sent to retrieve it.
      */
-    async #updateWatchedKeyValuesEtag(existingSettings: ConfigurationSetting[]): Promise<void> {
+    async #updateWatchedKeyValuesEtag(existingSettings: Map<string, ConfigurationSetting>): Promise<void> {
         for (const sentinel of this.#sentinels) {
-            const matchedSetting = existingSettings.find(s => s.key === sentinel.key && s.label === sentinel.label);
+            // try to find matching setting by key and label from the map's values
+            const matchedSetting = Array.from(existingSettings.values()).find(s => s.key === sentinel.key && s.label === sentinel.label);
             if (matchedSetting) {
                 sentinel.etag = matchedSetting.etag;
             } else {
@@ -621,7 +624,7 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
      */
     async #loadFeatureFlags() {
         const loadFeatureFlag = true;
-        const featureFlagSettings: ConfigurationSetting[] = await this.#loadConfigurationSettings(loadFeatureFlag);
+        const featureFlagSettings: Map<string, 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.
@@ -630,7 +633,8 @@ export class AzureAppConfigurationImpl implements AzureAppConfiguration {
 
         // parse feature flags
         const featureFlags = await Promise.all(
-            featureFlagSettings.map(setting => this.#parseFeatureFlag(setting))
+            featureFlagSettings.values()
+                .map(setting => this.#parseFeatureFlag(setting))
         );
 
         // feature_management is a reserved key, and feature_flags is an array of feature flags