feat: modular domain driven boilerplate

platform/config/dotenv.ts

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+import { load } from "@std/dotenv";
+
+const env = await load();
+
+/**
+ * TODO ...
+ */
+export function getDotEnvVariable(key: string): string {
+  return env[key] ?? Deno.env.get(key);
+}

platform/config/environment.ts

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+import { load } from "@std/dotenv";
+import { z, type ZodType } from "zod";
+
+import { InvalidEnvironmentKeyError } from "./errors.ts";
+import { getServiceEnvironment, type ServiceEnvironment } from "./service.ts";
+
+const env = await load();
+
+/**
+ * TODO ...
+ */
+export function getEnvironmentVariable<TType extends ZodType>({
+  key,
+  type,
+  envFallback,
+  fallback,
+}: {
+  key: string;
+  type: TType;
+  envFallback?: EnvironmentFallback;
+  fallback?: string;
+}): z.infer<TType> {
+  const serviceEnv = getServiceEnvironment();
+  const providedValue = env[key] ?? Deno.env.get(key);
+  const fallbackValue = typeof envFallback === "object" ? (envFallback[serviceEnv] ?? fallback) : fallback;
+  const toBeUsed = providedValue ?? fallbackValue;
+  try {
+    if (typeof toBeUsed === "string" && (toBeUsed.trim().startsWith("{") || toBeUsed.trim().startsWith("["))) {
+      return type.parse(JSON.parse(toBeUsed));
+    }
+    return type.parse(toBeUsed);
+  } catch (error) {
+    throw new InvalidEnvironmentKeyError(key, {
+      cause: error,
+    });
+  }
+}
+
+/*
+ |--------------------------------------------------------------------------------
+ | Types
+ |--------------------------------------------------------------------------------
+ */
+
+type EnvironmentFallback = Partial<Record<ServiceEnvironment, string>> & {
+  testing?: string;
+  local?: string;
+  stg?: string;
+  demo?: string;
+  prod?: string;
+};

platform/config/errors.ts

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+import { SERVICE_ENV } from "./service.ts";
+
+export class InvalidServiceEnvironmentError extends Error {
+  readonly code = "INVALID_SERVICE_ENVIRONMENT";
+
+  constructor(value: string) {
+    super(
+      `@platform/config requested invalid service environment, expected '${SERVICE_ENV.join(", ")}' got '${value}'.`,
+    );
+  }
+}
+
+export class InvalidEnvironmentKeyError extends Error {
+  readonly code = "INVALID_ENVIRONMENT_KEY";
+
+  constructor(
+    key: string,
+    readonly details: unknown,
+  ) {
+    super(`@platform/config invalid environment key '${key}' provided.`);
+  }
+}

platform/config/package.json

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+{
+  "name": "@platform/config",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "dependencies": {
+    "@std/dotenv": "npm:@jsr/std__dotenv@0.225.5",
+    "zod": "4.1.11"
+  }
+}

platform/config/service.ts

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+import { getDotEnvVariable } from "./dotenv.ts";
+
+export const SERVICE_ENV = ["testing", "local", "stg", "demo", "prod"] as const;
+
+/**
+ * TODO ...
+ */
+export function getServiceEnvironment(): ServiceEnvironment {
+  const value = getDotEnvVariable("SERVICE_ENV");
+  if (value === undefined) {
+    return "local";
+  }
+  if ((SERVICE_ENV as unknown as string[]).includes(value) === false) {
+    throw new Error(`Config Exception: Invalid env ${value} provided`);
+  }
+  return value as ServiceEnvironment;
+}
+
+export type ServiceEnvironment = (typeof SERVICE_ENV)[number];