Add validation for environment variables for Fantom (#52779)

Summary:
Pull Request resolved: #52779

Changelog: [internal]

Adds validation for Fantom environment variables at runtime, to catch typos or variables that no longer have an effect.

Reviewed By: rshest

Differential Revision: D78803045

fbshipit-source-id: efb28a4f3fd6a4be35fb525d91fb093a1e88f7e4

Author: rubennorte

private/react-native-fantom/runner/EnvironmentOptions.js

@@ -8,6 +8,16 @@
  * @format
  */
 
+const VALID_ENVIRONMENT_VARIABLES = [
+  'FANTOM_DEBUG_CPP',
+  'FANTOM_ENABLE_CPP_DEBUGGING',
+  'FANTOM_FORCE_CI_MODE',
+  'FANTOM_FORCE_OSS_BUILD',
+  'FANTOM_FORCE_TEST_MODE',
+  'FANTOM_LOG_COMMANDS',
+  'FANTOM_PRINT_OUTPUT',
+];
+
 /**
  * Prints the output of the Fantom tester to the test output.
  */
@@ -49,3 +59,20 @@ export const isCI: boolean =
 export const forceTestModeForBenchmarks: boolean = Boolean(
   process.env.FANTOM_FORCE_TEST_MODE,
 );
+
+/**
+ * Throws an error if there is an environment variable defined with the FANTOM_
+ * prefix that is not recognized.
+ */
+export function validateEnvironmentVariables(): void {
+  for (const key of Object.keys(process.env)) {
+    if (
+      key.startsWith('FANTOM_') &&
+      !VALID_ENVIRONMENT_VARIABLES.includes(key)
+    ) {
+      throw new Error(
+        `Unexpected Fantom environment variable: ${key}=${String(process.env[key])}. Accepted variables are: ${VALID_ENVIRONMENT_VARIABLES.join(', ')}`,
+      );
+    }
+  }
+}

private/react-native-fantom/runner/global-setup/globalSetup.js

@@ -8,13 +8,15 @@
  * @format
  */
 
-import {isOSS} from '../EnvironmentOptions';
+import {isOSS, validateEnvironmentVariables} from '../EnvironmentOptions';
 import build from './build';
 
 export default async function globalSetup(
   globalConfig: {...},
   projectConfig: {...},
 ): Promise<void> {
+  validateEnvironmentVariables();
+
   if (!isOSS) {
     await build();
   }