refactor: extract env var prefix constant

Author: tstephen-nhs

packages/cdkConstructs/src/config/index.ts

@@ -1,10 +1,11 @@
 import {CloudFormationClient, DescribeStacksCommand} from "@aws-sdk/client-cloudformation"
 import {S3Client, HeadObjectCommand} from "@aws-sdk/client-s3"
 import {StandardStackProps} from "../apps/createApp"
+import {ENV_DEFAULT_PREFIX} from "../constants"
 
 export function getConfigFromEnvVar(
   varName: string,
-  prefix: string = "CDK_CONFIG_",
+  prefix: string = ENV_DEFAULT_PREFIX,
   defaultValue: string | undefined = undefined
 ): string {
   const value = process.env[prefix + varName]
@@ -19,7 +20,7 @@ export function getConfigFromEnvVar(
 
 export function getBooleanConfigFromEnvVar(
   varName: string,
-  prefix: string = "CDK_CONFIG_",
+  prefix: string = ENV_DEFAULT_PREFIX,
   defaultValue: string | undefined = undefined
 ): boolean {
   const value = getConfigFromEnvVar(varName, prefix, defaultValue)
@@ -28,7 +29,7 @@ export function getBooleanConfigFromEnvVar(
 
 export function getNumberConfigFromEnvVar(
   varName: string,
-  prefix: string = "CDK_CONFIG_",
+  prefix: string = ENV_DEFAULT_PREFIX,
   defaultValue: string | undefined = undefined
 ): number {
   const value = getConfigFromEnvVar(varName, prefix, defaultValue)

packages/cdkConstructs/src/constants.ts

@@ -1,5 +1,8 @@
 import {Fn} from "aws-cdk-lib"
 
+/** Default prefix used for CDK config environment variables. */
+export const ENV_DEFAULT_PREFIX = "CDK_CONFIG_"
+
 /** Imported cross-stack account resource values used by constructs in this package. */
 export const ACCOUNT_RESOURCES = {
   CloudwatchEncryptionKMSPolicyArn: Fn.importValue("account-resources:CloudwatchEncryptionKMSPolicyArn"),

packages/cdkConstructs/tests/apps/createApp.test.ts

@@ -24,6 +24,7 @@ import {
 } from "vitest"
 import {createApp, type CreateAppParams} from "../../src/apps/createApp"
 import {AwsSolutionsChecks} from "cdk-nag"
+import {ENV_DEFAULT_PREFIX} from "../../src/constants"
 
 describe("createApp", () => {
   const originalEnv = process.env
@@ -51,10 +52,10 @@ describe("createApp", () => {
 
   describe("when all environment variables are set", () => {
     beforeEach(() => {
-      process.env.CDK_CONFIG_versionNumber = "1.2.3"
-      process.env.CDK_CONFIG_commitId = "abc123def456"
-      process.env.CDK_CONFIG_isPullRequest = "false"
-      process.env.CDK_CONFIG_environment = "test-environment"
+      process.env[`${ENV_DEFAULT_PREFIX}versionNumber`] = "1.2.3"
+      process.env[`${ENV_DEFAULT_PREFIX}commitId`] = "abc123def456"
+      process.env[`${ENV_DEFAULT_PREFIX}isPullRequest`] = "false"
+      process.env[`${ENV_DEFAULT_PREFIX}environment`] = "test-environment"
     })
 
     test("creates an App with correct configuration", () => {
@@ -124,10 +125,10 @@ describe("createApp", () => {
 
   describe("when isPullRequest is true", () => {
     beforeEach(() => {
-      process.env.CDK_CONFIG_versionNumber = "0.0.1-pr"
-      process.env.CDK_CONFIG_commitId = "pr123"
-      process.env.CDK_CONFIG_isPullRequest = "true"
-      process.env.CDK_CONFIG_environment = "test-environment"
+      process.env[`${ENV_DEFAULT_PREFIX}versionNumber`] = "0.0.1-pr"
+      process.env[`${ENV_DEFAULT_PREFIX}commitId`] = "pr123"
+      process.env[`${ENV_DEFAULT_PREFIX}isPullRequest`] = "true"
+      process.env[`${ENV_DEFAULT_PREFIX}environment`] = "test-environment"
     })
 
     test("correctly modifies props", () => {
@@ -159,41 +160,41 @@ describe("createApp", () => {
   describe("when environment variables are missing", () => {
 
     test("throws error when versionNumber is not set", () => {
-      process.env.CDK_CONFIG_commitId = "abc123"
-      process.env.CDK_CONFIG_isPullRequest = "false"
-      process.env.CDK_CONFIG_environment = "test-environment"
+      process.env[`${ENV_DEFAULT_PREFIX}commitId`] = "abc123"
+      process.env[`${ENV_DEFAULT_PREFIX}isPullRequest`] = "false"
+      process.env[`${ENV_DEFAULT_PREFIX}environment`] = "test-environment"
 
       expect(() => {
         createApp(buildParams())
-      }).toThrow("Environment variable CDK_CONFIG_versionNumber is not set")
+      }).toThrow(`Environment variable ${ENV_DEFAULT_PREFIX}versionNumber is not set`)
     })
 
     test("throws error when commitId is not set", () => {
-      process.env.CDK_CONFIG_versionNumber = "1.0.0"
-      process.env.CDK_CONFIG_isPullRequest = "false"
-      process.env.CDK_CONFIG_environment = "test-environment"
+      process.env[`${ENV_DEFAULT_PREFIX}versionNumber`] = "1.0.0"
+      process.env[`${ENV_DEFAULT_PREFIX}isPullRequest`] = "false"
+      process.env[`${ENV_DEFAULT_PREFIX}environment`] = "test-environment"
 
       expect(() => {
         createApp(buildParams())
-      }).toThrow("Environment variable CDK_CONFIG_commitId is not set")
+      }).toThrow(`Environment variable ${ENV_DEFAULT_PREFIX}commitId is not set`)
     })
 
     test("throws error when isPullRequest is not set", () => {
-      process.env.CDK_CONFIG_versionNumber = "1.0.0"
-      process.env.CDK_CONFIG_commitId = "abc123"
-      process.env.CDK_CONFIG_environment = "test-environment"
+      process.env[`${ENV_DEFAULT_PREFIX}versionNumber`] = "1.0.0"
+      process.env[`${ENV_DEFAULT_PREFIX}commitId`] = "abc123"
+      process.env[`${ENV_DEFAULT_PREFIX}environment`] = "test-environment"
       expect(() => {
         createApp(buildParams())
-      }).toThrow("Environment variable CDK_CONFIG_isPullRequest is not set")
+      }).toThrow(`Environment variable ${ENV_DEFAULT_PREFIX}isPullRequest is not set`)
     })
 
     test("throws error when environment is not set", () => {
-      process.env.CDK_CONFIG_versionNumber = "1.0.0"
-      process.env.CDK_CONFIG_commitId = "abc123"
-      process.env.CDK_CONFIG_isPullRequest = "false"
+      process.env[`${ENV_DEFAULT_PREFIX}versionNumber`] = "1.0.0"
+      process.env[`${ENV_DEFAULT_PREFIX}commitId`] = "abc123"
+      process.env[`${ENV_DEFAULT_PREFIX}isPullRequest`] = "false"
       expect(() => {
         createApp(buildParams())
-      }).toThrow("Environment variable CDK_CONFIG_environment is not set")
+      }).toThrow(`Environment variable ${ENV_DEFAULT_PREFIX}environment is not set`)
     })
 
   })

packages/cdkConstructs/tests/config/index.test.ts

@@ -12,6 +12,7 @@ import {
   getNumberConfigFromEnvVar,
   getTrustStoreVersion
 } from "../../src/config/index"
+import {ENV_DEFAULT_PREFIX} from "../../src/constants"
 
 const mockCloudFormationSend = vi.fn()
 const mockS3Send = vi.fn()
@@ -88,22 +89,22 @@ describe("config helpers", () => {
   })
 
   test("getConfigFromEnvVar returns the configured value", () => {
-    process.env.CDK_CONFIG_STACK_NAME = "primary"
+    process.env[`${ENV_DEFAULT_PREFIX}STACK_NAME`] = "primary"
 
     expect(getConfigFromEnvVar("STACK_NAME")).toBe("primary")
   })
 
   test("getConfigFromEnvVar returns the default value when env var is not set", () => {
-    delete process.env.CDK_CONFIG_MISSING
+    delete process.env[`${ENV_DEFAULT_PREFIX}MISSING`]
 
-    expect(getConfigFromEnvVar("MISSING", "CDK_CONFIG_", "fallback")).toBe("fallback")
+    expect(getConfigFromEnvVar("MISSING", ENV_DEFAULT_PREFIX, "fallback")).toBe("fallback")
   })
 
   test("getConfigFromEnvVar throws when value is missing", () => {
-    delete process.env.CDK_CONFIG_MISSING
+    delete process.env[`${ENV_DEFAULT_PREFIX}MISSING`]
 
     expect(() => getConfigFromEnvVar("MISSING"))
-      .toThrow("Environment variable CDK_CONFIG_MISSING is not set")
+      .toThrow(`Environment variable ${ENV_DEFAULT_PREFIX}MISSING is not set`)
   })
 
   test("getConfigFromEnvVar supports alternate prefixes", () => {
@@ -113,36 +114,36 @@ describe("config helpers", () => {
   })
 
   test("getBooleanConfigFromEnvVar maps string booleans", () => {
-    process.env.CDK_CONFIG_FEATURE_FLAG = "true "
-    process.env.CDK_CONFIG_OTHER_FLAG = " false"
+    process.env[`${ENV_DEFAULT_PREFIX}FEATURE_FLAG`] = "true "
+    process.env[`${ENV_DEFAULT_PREFIX}OTHER_FLAG`] = " false"
 
     expect(getBooleanConfigFromEnvVar("FEATURE_FLAG")).toBe(true)
     expect(getBooleanConfigFromEnvVar("OTHER_FLAG")).toBe(false)
   })
 
   test("getBooleanConfigFromEnvVar uses default value when env var is not set", () => {
-    delete process.env.CDK_CONFIG_BOOL_MISSING
+    delete process.env[`${ENV_DEFAULT_PREFIX}BOOL_MISSING`]
 
-    expect(getBooleanConfigFromEnvVar("BOOL_MISSING", "CDK_CONFIG_", "true")).toBe(true)
-    expect(getBooleanConfigFromEnvVar("BOOL_MISSING", "CDK_CONFIG_", "false")).toBe(false)
+    expect(getBooleanConfigFromEnvVar("BOOL_MISSING", ENV_DEFAULT_PREFIX, "true")).toBe(true)
+    expect(getBooleanConfigFromEnvVar("BOOL_MISSING", ENV_DEFAULT_PREFIX, "false")).toBe(false)
   })
 
   test("getNumberConfigFromEnvVar parses numeric strings", () => {
-    process.env.CDK_CONFIG_TIMEOUT = "45"
+    process.env[`${ENV_DEFAULT_PREFIX}TIMEOUT`] = "45"
 
     expect(getNumberConfigFromEnvVar("TIMEOUT")).toBe(45)
   })
 
   test("getNumberConfigFromEnvVar uses default value when env var is not set", () => {
-    delete process.env.CDK_CONFIG_NUM_MISSING
+    delete process.env[`${ENV_DEFAULT_PREFIX}NUM_MISSING`]
 
-    expect(getNumberConfigFromEnvVar("NUM_MISSING", "CDK_CONFIG_", "99")).toBe(99)
+    expect(getNumberConfigFromEnvVar("NUM_MISSING", ENV_DEFAULT_PREFIX, "99")).toBe(99)
   })
 
   test("getConfigFromEnvVar ignores default value when env var is set", () => {
-    process.env.CDK_CONFIG_STACK_NAME = "primary"
+    process.env[`${ENV_DEFAULT_PREFIX}STACK_NAME`] = "primary"
 
-    expect(getConfigFromEnvVar("STACK_NAME", "CDK_CONFIG_", "ignored")).toBe("primary")
+    expect(getConfigFromEnvVar("STACK_NAME", ENV_DEFAULT_PREFIX, "ignored")).toBe("primary")
   })
 
   test("getTrustStoreVersion returns the version ID from S3", async () => {