feat(nuxt): core API & flat layout support

.changeset/nuxt-flat-layout.md

@@ -0,0 +1,12 @@
+---
+"@arkenv/nuxt": patch
+"@arkenv/build": patch
+---
+
+#### Add flat layout support to `@arkenv/nuxt`
+
+Introduce flat layout schema support and typesafe `createEnv` signature overloads to `@arkenv/nuxt`.
+
+- Add `"flat"` layout mode to `ModuleOptions` and auto-detect it when a single `env.ts` file is configured.
+- Emit a deprecation warning in development when using the legacy `"simple"` layout option.
+- Expose flat `createEnv(schema, options)` overload with type inference for `NUXT_PUBLIC_` prefixes, `NODE_ENV`, and custom `exposeToClient` variables.

packages/build/src/index.test.ts

@@ -0,0 +1,134 @@
+import { describe, expect, it } from "vitest";
+import {
+	extractArkenvBlock,
+	extractBlock,
+	extractKeys,
+	parseBlockKeys,
+} from "./index";
+
+describe("@arkenv/build extractors", () => {
+	describe("extractKeys", () => {
+		it("should extract keys from legacy nested layout schema", () => {
+			const content = `
+				export const env = createEnv({
+					server: {
+						DATABASE_URL: "string",
+						ADMIN_TOKEN: "string"
+					},
+					client: {
+						NEXT_PUBLIC_API_URL: "string",
+						NEXT_PUBLIC_APP_ENV: "string"
+					},
+					shared: {
+						NODE_ENV: "string"
+					}
+				});
+			`;
+			const res = extractKeys(content, "NEXT_PUBLIC_");
+			expect(res.isLegacy).toBe(true);
+			expect(res.serverKeys).toEqual(["DATABASE_URL", "ADMIN_TOKEN"]);
+			expect(res.clientKeys).toEqual([
+				"NEXT_PUBLIC_API_URL",
+				"NEXT_PUBLIC_APP_ENV",
+			]);
+			expect(res.sharedKeys).toEqual(["NODE_ENV"]);
+		});
+
+		it("should extract keys from flat layout schema with NEXT_PUBLIC_ prefix", () => {
+			const content = `
+				export const env = createEnv({
+					DATABASE_URL: "string",
+					NEXT_PUBLIC_API_URL: "string",
+					NODE_ENV: "string",
+					CUSTOM_VAR: "string"
+				}, {
+					exposeToClient: ["CUSTOM_VAR"]
+				});
+			`;
+			const res = extractKeys(content, "NEXT_PUBLIC_");
+			expect(res.isLegacy).toBe(false);
+			expect(res.serverKeys).toEqual(["DATABASE_URL"]);
+			expect(res.clientKeys).toEqual(["NEXT_PUBLIC_API_URL"]);
+			expect(res.sharedKeys).toEqual(["NODE_ENV", "CUSTOM_VAR"]);
+		});
+
+		it("should extract keys from flat layout schema with NUXT_PUBLIC_ prefix", () => {
+			const content = `
+				export const env = arkenv({
+					DATABASE_URL: "string",
+					NUXT_PUBLIC_API_URL: "string",
+					NODE_ENV: "string",
+					CUSTOM_VAR: "string"
+				}, {
+					exposeToClient: ["CUSTOM_VAR"]
+				});
+			`;
+			const res = extractKeys(content, "NUXT_PUBLIC_");
+			expect(res.isLegacy).toBe(false);
+			expect(res.serverKeys).toEqual(["DATABASE_URL"]);
+			expect(res.clientKeys).toEqual(["NUXT_PUBLIC_API_URL"]);
+			expect(res.sharedKeys).toEqual(["NODE_ENV", "CUSTOM_VAR"]);
+		});
+	});
+
+	describe("extractBlock", () => {
+		it("should extract a specified block body", () => {
+			const content = `
+				createEnv({
+					server: {
+						DB_URL: "string"
+					},
+					client: {
+						API_URL: "string"
+					}
+				})
+			`;
+			expect(extractBlock(content, "server")).toBe('DB_URL: "string"');
+			expect(extractBlock(content, "client")).toBe('API_URL: "string"');
+		});
+
+		it("should return null for non-existent block", () => {
+			const content = "createEnv({ server: {} })";
+			expect(extractBlock(content, "shared")).toBeNull();
+		});
+	});
+
+	describe("parseBlockKeys", () => {
+		it("should parse standard, quoted, and comment-wrapped keys", () => {
+			const content = `
+				DATABASE_URL: "string",
+				"NUXT_PUBLIC_API_URL": "string",
+				'SINGLE_QUOTED': "string",
+				// Ignored key: "value",
+				/* Multi-line ignored: "value" */
+				nested: {
+					INNER_KEY: "string"
+				},
+				PORT: 3000
+			`;
+			const keys = parseBlockKeys(content);
+			expect(keys).toEqual([
+				"DATABASE_URL",
+				"NUXT_PUBLIC_API_URL",
+				"SINGLE_QUOTED",
+				"nested",
+				"PORT",
+			]);
+		});
+	});
+
+	describe("extractArkenvBlock", () => {
+		it("should extract the arkenv block content", () => {
+			const content = `
+				import { arkenv } from "arkenv";
+				export const env = arkenv({
+					DATABASE_URL: "string",
+					PORT: "number"
+				});
+			`;
+			expect(extractArkenvBlock(content)).toBe(
+				'DATABASE_URL: "string",\n\t\t\t\t\tPORT: "number"',
+			);
+		});
+	});
+});