1 files changed, 43 insertions, 0 deletions
diff --git a/src/lib/env.ts b/src/lib/env.ts
new file mode 100644
index 0000000..20f18f5
--- /dev/null
+++ b/src/lib/env.ts
@@ -0,0 +1,43 @@
+import dotenv from 'dotenv';
+
+// Parsing the env file.
+dotenv.config({ path: '../../.env' });
+
+type Env = {
+  PAYPAL_LIVE_CLIENT_ID: string,
+  PAYPAL_SANDBOX_CLIENT_ID: string,
+  ENVIRONMENT: 'dev' | 'prod',
+};
+
+type DirtyEnv = { [key in keyof Env]?: string };
+
+const ENV: { [key in keyof Env]: number } = {
+  PAYPAL_LIVE_CLIENT_ID: 1,
+  PAYPAL_SANDBOX_CLIENT_ID: 1,
+  ENVIRONMENT: 1,
+};
+
+const { env }: { env: DirtyEnv } = process;
+
+const sanitisedEnvEntries =
+  (Object.keys(ENV) as (keyof Env)[])
+  .map<[keyof Env, string]>(key => {
+    const value = env[key];
+    if (!value) {
+      throw new Error(`Environment not configured correctly. ${key} was not defined.`);
+    }
+
+    if (key === 'ENVIRONMENT') {
+      if (!['dev', 'prod'].includes(value)) {
+        throw new Error(`
+          Environment not configured correctly. ${key} must be
+          either 'dev' or 'prod', but '${value}' was provided.
+        `);
+      }
+    }
+    return [key, value];
+  });
+
+const sanitisedEnv = Object.fromEntries(sanitisedEnvEntries) as Env;
+
+export default sanitisedEnv;
+\ No newline at end of file