refactor(parameters): replace EnvironmentVariablesService class with helper functions in Parameters

packages/commons/src/envUtils.ts

@@ -301,6 +301,15 @@ const getXRayTraceIdFromEnv = (): string | undefined => {
   return xRayTraceData?.Root;
 };
 
+/**
+ * Helper function to determine if a value is considered thruthy.
+ *
+ * @param value The value to check for truthiness.
+ */
+const isValueTrue = (value: string): boolean => {
+  return truthyValues.has(value.toLowerCase());
+};
+
 export {
   getStringFromEnv,
   getNumberFromEnv,
@@ -310,4 +319,5 @@ export {
   getXrayTraceDataFromEnv,
   isRequestXRaySampled,
   getXRayTraceIdFromEnv,
+  isValueTrue,
 };

packages/commons/tests/unit/envUtils.test.ts

@@ -7,6 +7,7 @@ import {
   getXRayTraceIdFromEnv,
   isDevMode,
   isRequestXRaySampled,
+  isValueTrue,
 } from '../../src/envUtils.js';
 
 describe('Functions: envUtils', () => {
@@ -330,4 +331,31 @@ describe('Functions: envUtils', () => {
       expect(value).toEqual(false);
     });
   });
+
+  describe('Function: isValueTrue', () => {
+    const valuesToTest: Array<Array<string | boolean>> = [
+      ['1', true],
+      ['y', true],
+      ['yes', true],
+      ['t', true],
+      ['TRUE', true],
+      ['on', true],
+      ['', false],
+      ['false', false],
+      ['fasle', false],
+      ['somethingsilly', false],
+      ['0', false],
+    ];
+
+    it.each(valuesToTest)(
+      'takes string "%s" and returns %s',
+      (input, output) => {
+        // Prepare
+        // Act
+        const value = isValueTrue(input as string);
+        // Assess
+        expect(value).toBe(output);
+      }
+    );
+  });
 });

packages/parameters/src/appconfig/AppConfigProvider.ts

@@ -1,3 +1,4 @@
+import { getServiceName } from '@aws-lambda-powertools/commons/utils/env';
 import type { StartConfigurationSessionCommandInput } from '@aws-sdk/client-appconfigdata';
 import {
   AppConfigDataClient,
@@ -206,7 +207,7 @@ class AppConfigProvider extends BaseProvider {
     });
 
     const { application, environment } = options;
-    this.application = application ?? this.envVarsService.getServiceName();
+    this.application = application ?? getServiceName();
     if (!this.application || this.application.trim().length === 0) {
       throw new Error(
         'Application name is not defined or POWERTOOLS_SERVICE_NAME is not set'

packages/parameters/src/base/BaseProvider.ts

@@ -5,7 +5,6 @@ import {
   isSdkClient,
   isString,
 } from '@aws-lambda-powertools/commons';
-import { EnvironmentVariablesService } from '../config/EnvironmentVariablesService.js';
 import { GetParameterError, TransformParameterError } from '../errors.js';
 import type {
   BaseProviderConstructorOptions,
@@ -38,7 +37,6 @@ import { transformValue } from './transformValue.js';
  * this should be an acceptable tradeoff.
  */
 abstract class BaseProvider implements BaseProviderInterface {
-  public envVarsService: EnvironmentVariablesService;
   protected client: unknown;
   protected store: Map<string, ExpirableValue>;
 
@@ -48,7 +46,6 @@ abstract class BaseProvider implements BaseProviderInterface {
     awsSdkV3ClientPrototype,
   }: BaseProviderConstructorOptions) {
     this.store = new Map();
-    this.envVarsService = new EnvironmentVariablesService();
     if (awsSdkV3Client) {
       if (!isSdkClient(awsSdkV3Client) && awsSdkV3ClientPrototype) {
         console.warn(
@@ -96,7 +93,7 @@ abstract class BaseProvider implements BaseProviderInterface {
     name: string,
     options?: GetOptionsInterface
   ): Promise<unknown | undefined> {
-    const configs = new GetOptions(this.envVarsService, options);
+    const configs = new GetOptions(options);
     const key = [name, configs.transform].toString();
 
     if (!configs.forceFetch && !this.hasKeyExpiredInCache(key)) {
@@ -135,7 +132,7 @@ abstract class BaseProvider implements BaseProviderInterface {
     path: string,
     options?: GetMultipleOptionsInterface
   ): Promise<unknown> {
-    const configs = new GetMultipleOptions(this.envVarsService, options);
+    const configs = new GetMultipleOptions(options);
     const key = [path, configs.transform].toString();
 
     if (!configs.forceFetch && !this.hasKeyExpiredInCache(key)) {

packages/parameters/src/base/GetMultipleOptions.ts

@@ -1,4 +1,3 @@
-import type { EnvironmentVariablesService } from '../config/EnvironmentVariablesService.js';
 import type { GetMultipleOptionsInterface } from '../types/BaseProvider.js';
 import { GetOptions } from './GetOptions.js';
 
@@ -13,11 +12,8 @@ class GetMultipleOptions
 {
   public throwOnTransformError = false;
 
-  public constructor(
-    envVarsService: EnvironmentVariablesService,
-    options: GetMultipleOptionsInterface = {}
-  ) {
-    super(envVarsService, options);
+  public constructor(options: GetMultipleOptionsInterface = {}) {
+    super(options);
 
     if (options.throwOnTransformError !== undefined) {
       this.throwOnTransformError = options.throwOnTransformError;

packages/parameters/src/base/GetOptions.ts

@@ -1,9 +1,9 @@
-import type { EnvironmentVariablesService } from '../config/EnvironmentVariablesService.js';
 import { DEFAULT_MAX_AGE_SECS } from '../constants.js';
 import type {
   GetOptionsInterface,
   TransformOptions,
 } from '../types/BaseProvider.js';
+import { getParametersMaxAge } from '../utils/env.js';
 
 /**
  * Options for the `get` method.
@@ -16,15 +16,11 @@ class GetOptions implements GetOptionsInterface {
   public sdkOptions?: unknown;
   public transform?: TransformOptions;
 
-  public constructor(
-    envVarsService: EnvironmentVariablesService,
-    options: GetOptionsInterface = {}
-  ) {
+  public constructor(options: GetOptionsInterface = {}) {
     Object.assign(this, options);
 
     if (options.maxAge === undefined) {
-      this.maxAge =
-        envVarsService.getParametersMaxAge() ?? DEFAULT_MAX_AGE_SECS;
+      this.maxAge = getParametersMaxAge() ?? DEFAULT_MAX_AGE_SECS;
     }
   }
 }

packages/parameters/src/ssm/SSMProvider.ts

@@ -1,4 +1,5 @@
 import type { JSONValue } from '@aws-lambda-powertools/commons/types';
+import { isValueTrue } from '@aws-lambda-powertools/commons/utils/env';
 import type {
   GetParameterCommandInput,
   GetParametersByPathCommandInput,
@@ -32,6 +33,7 @@ import type {
   SSMSetOptions,
   SSMSplitBatchAndDecryptParametersOutputType,
 } from '../types/SSMProvider.js';
+import { getSSMDecrypt } from '../utils/env.js';
 
 /**
  * ## Intro
@@ -843,10 +845,8 @@ class SSMProvider extends BaseProvider {
     if (options?.decrypt !== undefined) return options.decrypt;
     if (sdkOptions?.WithDecryption !== undefined)
       return sdkOptions.WithDecryption;
-    if (this.envVarsService.getSSMDecrypt() !== '') {
-      return this.envVarsService.isValueTrue(
-        this.envVarsService.getSSMDecrypt()
-      );
+    if (getSSMDecrypt() !== '') {
+      return isValueTrue(getSSMDecrypt());
     }
 
     return undefined;

packages/parameters/src/utils/env.ts

@@ -0,0 +1,33 @@
+import {
+  getNumberFromEnv,
+  getStringFromEnv,
+} from '@aws-lambda-powertools/commons/utils/env';
+
+/**
+ * It returns the value of the POWERTOOLS_PARAMETERS_MAX_AGE environment variable.
+ *
+ * @returns {number|undefined}
+ */
+const getParametersMaxAge = (): number | undefined => {
+  try {
+    return getNumberFromEnv({
+      key: 'POWERTOOLS_PARAMETERS_MAX_AGE',
+    });
+  } catch (error) {
+    return undefined;
+  }
+};
+
+/**
+ * It returns the value of the POWERTOOLS_PARAMETERS_SSM_DECRYPT environment variable.
+ *
+ * @returns {string}
+ */
+const getSSMDecrypt = (): string => {
+  return getStringFromEnv({
+    key: 'POWERTOOLS_PARAMETERS_SSM_DECRYPT',
+    defaultValue: '',
+  });
+};
+
+export { getParametersMaxAge, getSSMDecrypt };