feat(commons): make utilities aware of provisioned concurrency

Author: dreamorosi

packages/commons/src/Utility.ts

@@ -51,15 +51,43 @@
  * ```
  */
 export class Utility {
+  #initializationType: 'unknown' | 'on-demand' | 'provisioned-concurrency';
   protected coldStart = true;
   protected readonly defaultServiceName: string = 'service_undefined';
 
+  public constructor() {
+    this.#initializationType = this.getInitializationType();
+    if (this.#initializationType !== 'on-demand') {
+      this.coldStart = false;
+    }
+  }
+
+  /**
+   * Get the value of the `POWERTOOLS_SERVICE_NAME` environment variable.
+   */
+  protected getInitializationType():
+    | 'unknown'
+    | 'on-demand'
+    | 'provisioned-concurrency' {
+    const envVarValue = process.env.AWS_LAMBDA_INITIALIZATION_TYPE?.trim();
+    if (envVarValue === 'on-demand') {
+      return 'on-demand';
+    }
+    if (envVarValue === 'provisioned-concurrency') {
+      return 'provisioned-concurrency';
+    }
+    return 'unknown';
+  }
+
   /**
    * Get the cold start status of the current execution environment.
    *
    * The method also flips the cold start status to `false` after the first invocation.
    */
   protected getColdStart(): boolean {
+    if (this.#initializationType !== 'on-demand') {
+      return false;
+    }
     if (this.coldStart) {
       this.coldStart = false;
 

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

@@ -15,6 +15,12 @@ describe('Class: Utility', () => {
     public validateServiceName(serviceName: string): boolean {
       return this.isValidServiceName(serviceName);
     }
+    public getInitializationType():
+      | 'unknown'
+      | 'on-demand'
+      | 'provisioned-concurrency' {
+      return super.getInitializationType();
+    }
   }
 
   it('returns the correct cold start value', () => {
@@ -27,6 +33,15 @@ describe('Class: Utility', () => {
     expect(utility.dummyMethod()).toBe(false);
   });
 
+  it('returns the correct cold start value when provisioned concurrency is used', () => {
+    // Prepare
+    process.env.AWS_LAMBDA_INITIALIZATION_TYPE = 'provisioned-concurrency';
+    const utility = new TestUtility();
+
+    // Act & Assess
+    expect(utility.dummyMethod()).toBe(false);
+  });
+
   it('flips the cold start value', () => {
     // Prepare
     const utility = new TestUtility();
@@ -54,4 +69,23 @@ describe('Class: Utility', () => {
     expect(utility.validateServiceName('serverlessAirline')).toBe(true);
     expect(utility.validateServiceName('')).toBe(false);
   });
+
+  it.each([
+    { value: 'on-demand', expected: 'on-demand' },
+    { value: 'provisioned-concurrency', expected: 'provisioned-concurrency' },
+    { value: '', expected: 'unknown' },
+  ])(
+    'returns the correct initialization type ($value)',
+    ({ value, expected }) => {
+      // Prepare
+      process.env.AWS_LAMBDA_INITIALIZATION_TYPE = value;
+      const utility = new TestUtility();
+
+      // Act
+      const initializationType = utility.getInitializationType();
+
+      // Assess
+      expect(initializationType).toBe(expected);
+    }
+  );
 });

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

@@ -6,6 +6,10 @@ import {
   PT_VERSION as version,
 } from '../../src/index.js';
 
+vi.hoisted(() => {
+  process.env.AWS_EXECUTION_ENV = '';
+});
+
 describe('Helpers: awsSdk', () => {
   describe('Function: userAgentMiddleware', () => {
     beforeAll(() => {

packages/commons/vitest.config.ts

@@ -3,5 +3,6 @@ import { defineProject } from 'vitest/config';
 export default defineProject({
   test: {
     environment: 'node',
+    setupFiles: ['../testing/src/setupEnv.ts'],
   },
 });

packages/testing/src/setupEnv.ts

@@ -377,3 +377,4 @@ if (
 process.env._HANDLER = 'index.handler';
 process.env.POWERTOOLS_SERVICE_NAME = 'hello-world';
 process.env.AWS_XRAY_LOGGING_LEVEL = 'silent';
+process.env.AWS_LAMBDA_INITIALIZATION_TYPE = 'on-demand';