chore: prevent builds when vars are missing

tools/scripts/build/ensure-env.js

@@ -6,5 +6,40 @@ const env = require('../../../config/env');
 const clientPath = path.resolve(__dirname, '../../../client');
 const globalConfigPath = path.resolve(__dirname, '../../../config');
 
+const { FREECODECAMP_NODE_ENV } = process.env;
+
+if (FREECODECAMP_NODE_ENV === 'production') {
+  const locationKeys = [
+    'homeLocation',
+    'apiLocation',
+    'forumLocation',
+    'newsLocation'
+  ];
+  const deploymentKeys = ['locale', 'deploymentEnv', 'environment'];
+  const searchKeys = ['algoliaAppId', 'algoliaAPIKey'];
+  const donationKeys = ['stripePublicKey', 'paypalClientId'];
+
+  const expectedVariables = locationKeys.concat(
+    deploymentKeys,
+    searchKeys,
+    donationKeys
+  );
+  const variables = Object.keys(env);
+  expectedVariables.sort();
+  variables.sort();
+  if (expectedVariables.length !== variables.length) {
+    throw Error(`Env. variable validation failed. Expected
+    ${variables} to match
+    ${expectedVariables}
+    `);
+  }
+
+  for (const key of expectedVariables) {
+    if (!env[key]) {
+      throw Error(`Env. variable ${key} is missing, build cannot continue`);
+    }
+  }
+}
+
 fs.writeFileSync(`${clientPath}/config/env.json`, JSON.stringify(env));
 fs.writeFileSync(`${globalConfigPath}/env.json`, JSON.stringify(env));