fix: require env vars to be set and fail otherwise

Author: alfetopito

apps/cow-fi/util/environment.ts

@@ -7,15 +7,15 @@ function isEnvironmentName(value: string): value is EnvironmentName {
   return ALL_ENVIRONMENTS.includes(value as EnvironmentName)
 }
 
-function getConfiguredEnvironmentName(): EnvironmentName | undefined {
+function getConfiguredEnvironmentName(): EnvironmentName {
   const env = process.env[ENVIRONMENT_VAR_NAME]?.trim().toLowerCase()
 
   if (!env) {
-    return undefined
+    throw new Error(`Missing ${ENVIRONMENT_VAR_NAME}. Expected one of: ${ALL_ENVIRONMENTS.join(', ')}`)
   }
 
   if (!isEnvironmentName(env)) {
-    return undefined
+    throw new Error(`Invalid ${ENVIRONMENT_VAR_NAME}="${env}". Expected one of: ${ALL_ENVIRONMENTS.join(', ')}`)
   }
 
   return env
@@ -37,23 +37,10 @@ function getEnvironmentChecks(environmentName: EnvironmentName): EnvironmentChec
   }
 }
 
-function getDefaultEnvironmentChecks(): EnvironmentChecks {
-  return {
-    isLocal: false,
-    isDev: false,
-    isPr: false,
-    isProd: false,
-  }
-}
+const configuredEnvironmentName = getConfiguredEnvironmentName()
 
 export function checkEnvironment(): EnvironmentChecks {
-  const configuredEnvironmentName = getConfiguredEnvironmentName()
-
-  if (configuredEnvironmentName) {
-    return getEnvironmentChecks(configuredEnvironmentName)
-  }
-
-  return getDefaultEnvironmentChecks()
+  return getEnvironmentChecks(configuredEnvironmentName)
 }
 
 const { isLocal, isDev, isPr, isProd } = checkEnvironmentUsingWindow()
@@ -62,7 +49,7 @@ function checkEnvironmentUsingWindow(): EnvironmentChecks {
   return checkEnvironment()
 }
 
-function getEnvironmentName(): EnvironmentName | undefined {
+function getEnvironmentName(): EnvironmentName {
   if (isProd) {
     return 'production'
   } else if (isPr) {
@@ -72,10 +59,10 @@ function getEnvironmentName(): EnvironmentName | undefined {
   } else if (isLocal) {
     return 'local'
   } else {
-    return undefined
+    return configuredEnvironmentName
   }
 }
 
-export const environmentName: EnvironmentName | undefined = getEnvironmentName()
+export const environmentName: EnvironmentName = getEnvironmentName()
 
 export { isLocal, isDev, isPr, isProd }

apps/cow-fi/util/environments.test.ts

@@ -1,73 +1,69 @@
-import { checkEnvironment, EnvironmentChecks } from './environment'
+const ENVIRONMENT_VAR_NAME = 'NEXT_PUBLIC_ENVIRONMENT'
+const originalEnvironment = process.env[ENVIRONMENT_VAR_NAME]
 
-const DEFAULT_ENVIRONMENTS_CHECKS: EnvironmentChecks = {
+const DEFAULT_ENVIRONMENTS_CHECKS = {
   isProd: false,
   isPr: false,
   isDev: false,
   isLocal: false,
 }
 
 describe('Detect environments using configured env var', () => {
-  const ENVIRONMENT_VAR_NAME = 'NEXT_PUBLIC_ENVIRONMENT'
-  const originalEnvironment = process.env[ENVIRONMENT_VAR_NAME]
-
   afterEach(() => {
+    jest.resetModules()
+
     if (typeof originalEnvironment === 'undefined') {
       delete process.env[ENVIRONMENT_VAR_NAME]
     } else {
       process.env[ENVIRONMENT_VAR_NAME] = originalEnvironment
     }
   })
 
-  describe('No configured environment', () => {
-    it('returns no active envs', () => {
-      expect(checkEnvironment()).toEqual(DEFAULT_ENVIRONMENTS_CHECKS)
-    })
-  })
+  it('throws when the env var is missing', async () => {
+    delete process.env[ENVIRONMENT_VAR_NAME]
 
-  describe('Is production', () => {
-    const isProduction = { ...DEFAULT_ENVIRONMENTS_CHECKS, isProd: true }
+    await expect(import('./environment')).rejects.toThrow(`Missing ${ENVIRONMENT_VAR_NAME}`)
+  })
 
-    it('uses env var override', () => {
-      process.env[ENVIRONMENT_VAR_NAME] = 'production'
+  it('throws when the env var is invalid', async () => {
+    process.env[ENVIRONMENT_VAR_NAME] = 'invalid-environment'
 
-      expect(checkEnvironment()).toEqual(isProduction)
-    })
+    await expect(import('./environment')).rejects.toThrow(`Invalid ${ENVIRONMENT_VAR_NAME}="invalid-environment"`)
   })
 
-  describe('Is PR', () => {
-    const isPr = { ...DEFAULT_ENVIRONMENTS_CHECKS, isPr: true }
+  it('uses production env var override', async () => {
+    process.env[ENVIRONMENT_VAR_NAME] = 'production'
 
-    it('uses env var override', () => {
-      process.env[ENVIRONMENT_VAR_NAME] = 'pr'
+    const { checkEnvironment, environmentName } = await import('./environment')
 
-      expect(checkEnvironment()).toEqual(isPr)
-    })
+    expect(environmentName).toBe('production')
+    expect(checkEnvironment()).toEqual({ ...DEFAULT_ENVIRONMENTS_CHECKS, isProd: true })
   })
 
-  describe('Is Development', () => {
-    const isDevelopment = { ...DEFAULT_ENVIRONMENTS_CHECKS, isDev: true }
+  it('uses pr env var override', async () => {
+    process.env[ENVIRONMENT_VAR_NAME] = 'pr'
 
-    it('uses env var override', () => {
-      process.env[ENVIRONMENT_VAR_NAME] = 'development'
+    const { checkEnvironment, environmentName } = await import('./environment')
 
-      expect(checkEnvironment()).toEqual(isDevelopment)
-    })
+    expect(environmentName).toBe('pr')
+    expect(checkEnvironment()).toEqual({ ...DEFAULT_ENVIRONMENTS_CHECKS, isPr: true })
   })
 
-  describe('Is Local', () => {
-    const isLocal = { ...DEFAULT_ENVIRONMENTS_CHECKS, isLocal: true }
+  it('uses development env var override', async () => {
+    process.env[ENVIRONMENT_VAR_NAME] = 'development'
+
+    const { checkEnvironment, environmentName } = await import('./environment')
 
-    it('uses env var override', () => {
-      process.env[ENVIRONMENT_VAR_NAME] = 'local'
+    expect(environmentName).toBe('development')
+    expect(checkEnvironment()).toEqual({ ...DEFAULT_ENVIRONMENTS_CHECKS, isDev: true })
+  })
 
-      expect(checkEnvironment()).toEqual(isLocal)
-    })
+  it('uses local env var override', async () => {
+    process.env[ENVIRONMENT_VAR_NAME] = 'local'
 
-    it('returns no active envs when env var is invalid', () => {
-      process.env[ENVIRONMENT_VAR_NAME] = 'invalid-environment'
+    const { checkEnvironment, environmentName } = await import('./environment')
 
-      expect(checkEnvironment()).toEqual(DEFAULT_ENVIRONMENTS_CHECKS)
-    })
+    expect(environmentName).toBe('local')
+    expect(checkEnvironment()).toEqual({ ...DEFAULT_ENVIRONMENTS_CHECKS, isLocal: true })
   })
 })

apps/cowswap-frontend/jest.setup.ts

@@ -69,10 +69,12 @@ beforeEach(() => {
   __resetGtmInstance()
 })
 
-// eslint-disable-next-line @nx/enforce-module-boundaries
-import '../../jest.setup'
 import { i18n } from '@lingui/core'
 
+process.env.REACT_APP_ENVIRONMENT = 'production'
+
+require('../../jest.setup')
+
 i18n.load('en-US', {})
 i18n.activate('en-US')
 

apps/explorer/src/test/utils/env.test.ts

@@ -12,6 +12,18 @@ describe('explorer env detection', () => {
     }
   })
 
+  it('throws when the env var is missing', async () => {
+    delete process.env[ENVIRONMENT_VAR_NAME]
+
+    await expect(import('../../utils/env')).rejects.toThrow(`Missing ${ENVIRONMENT_VAR_NAME}`)
+  })
+
+  it('throws when the env var is invalid', async () => {
+    process.env[ENVIRONMENT_VAR_NAME] = 'invalid-environment'
+
+    await expect(import('../../utils/env')).rejects.toThrow(`Invalid ${ENVIRONMENT_VAR_NAME}="invalid-environment"`)
+  })
+
   it('uses the configured environment name', async () => {
     process.env[ENVIRONMENT_VAR_NAME] = 'production'
 
@@ -41,19 +53,4 @@ describe('explorer env detection', () => {
       isProd: false,
     })
   })
-
-  it('falls back when the configured environment is invalid', async () => {
-    process.env[ENVIRONMENT_VAR_NAME] = 'invalid-environment'
-
-    const { environmentName, checkEnvironment } = await import('../../utils/env')
-
-    expect(environmentName).toBeUndefined()
-    expect(checkEnvironment()).toEqual({
-      isLocal: false,
-      isDev: false,
-      isPr: false,
-      isStaging: false,
-      isProd: false,
-    })
-  })
 })

apps/explorer/src/utils/env.ts

@@ -15,15 +15,17 @@ function isEnvironmentName(value: string): value is Envs {
   return ALL_ENVIRONMENTS.includes(value as Envs)
 }
 
-function getConfiguredEnvironmentName(): Envs | undefined {
+function getConfiguredEnvironmentName(): Envs {
   const env = process.env[EXPLORER_ENVIRONMENT_VAR_NAME]?.trim().toLowerCase()
 
   if (!env) {
-    return undefined
+    throw new Error(`Missing ${EXPLORER_ENVIRONMENT_VAR_NAME}. Expected one of: ${ALL_ENVIRONMENTS.join(', ')}`)
   }
 
   if (!isEnvironmentName(env)) {
-    return undefined
+    throw new Error(
+      `Invalid ${EXPLORER_ENVIRONMENT_VAR_NAME}="${env}". Expected one of: ${ALL_ENVIRONMENTS.join(', ')}`,
+    )
   }
 
   return env
@@ -39,34 +41,16 @@ function getEnvironmentChecks(environmentName: Envs): EnvsFlags {
   }
 }
 
-function getDefaultEnvironmentChecks(): EnvsFlags {
-  return {
-    isLocal: false,
-    isDev: false,
-    isPr: false,
-    isStaging: false,
-    isProd: false,
-  }
-}
+const configuredEnvironmentName = getConfiguredEnvironmentName()
 
 export function checkEnvironment(): EnvsFlags {
-  const configuredEnvironmentName = getConfiguredEnvironmentName()
-
-  if (configuredEnvironmentName) {
-    return getEnvironmentChecks(configuredEnvironmentName)
-  }
-
-  return getDefaultEnvironmentChecks()
+  return getEnvironmentChecks(configuredEnvironmentName)
 }
 
 const { isLocal, isDev, isPr, isStaging, isProd } = checkEnvironment()
 
-function getEnvironmentName(): Envs | undefined {
-  const configuredEnvironmentName = getConfiguredEnvironmentName()
-
-  if (configuredEnvironmentName) {
-    return configuredEnvironmentName
-  } else if (isProd) {
+function getEnvironmentName(): Envs {
+  if (isProd) {
     return 'production'
   } else if (isStaging) {
     return 'staging'
@@ -77,10 +61,10 @@ function getEnvironmentName(): Envs | undefined {
   } else if (isLocal) {
     return 'local'
   } else {
-    return undefined
+    return configuredEnvironmentName
   }
 }
 
-export const environmentName: Envs | undefined = getEnvironmentName()
+export const environmentName: Envs = getEnvironmentName()
 
 export { isLocal, isDev, isPr, isStaging, isProd }

jest.setup.ts

@@ -7,6 +7,9 @@ import { TextDecoder, TextEncoder } from 'util'
 
 // For simplicity, we will use CowSwap default .env for all projects and libs
 config({ path: __dirname + '/apps/cowswap-frontend/.env' })
+config({ path: __dirname + '/apps/cowswap-frontend/.env.development' })
+config({ path: __dirname + '/apps/explorer/.env' })
+config({ path: __dirname + '/apps/cow-fi/.env' })
 
 if (typeof global.TextEncoder === 'undefined') {
   global.ReadableStream = Readable as unknown as typeof globalThis.ReadableStream