Remove proload for config loading (#5778)

* Refactor resolve and load config

* Add changeset

* Update name

* Remove unnecessary node_env handling

* Fix test

* Update comment

8 files changed, 65 insertions, 128 deletions

diff --git a/.changeset/calm-peas-doubt.md b/.changeset/calm-peas-doubt.md
new file mode 100644
index 000000000..68de7b3a6
--- /dev/null
+++ b/.changeset/calm-peas-doubt.md
@@ -0,0 +1,5 @@
+---
+'astro': major
+---
+
+Remove proload to load the Astro config. It will now use NodeJS and Vite to load the config only.
diff --git a/packages/astro/package.json b/packages/astro/package.json
index 8f3061082..f7ede273a 100644
--- a/packages/astro/package.json
+++ b/packages/astro/package.json
@@ -120,8 +120,6 @@
     "@babel/plugin-transform-react-jsx": "^7.17.12",
     "@babel/traverse": "^7.18.2",
     "@babel/types": "^7.18.4",
-    "@proload/core": "^0.3.3",
-    "@proload/plugin-tsm": "^0.2.1",
     "@types/babel__core": "^7.1.19",
     "@types/html-escaper": "^3.0.0",
     "@types/yargs-parser": "^21.0.0",
diff --git a/packages/astro/src/content/utils.ts b/packages/astro/src/content/utils.ts
index 07f19faf0..8d52fd01e 100644
--- a/packages/astro/src/content/utils.ts
+++ b/packages/astro/src/content/utils.ts
@@ -190,7 +190,6 @@ export async function loadContentConfig({
 	settings: AstroSettings;
 }): Promise<ContentConfig | Error> {
 	const contentPaths = getContentPaths({ srcDir: settings.config.srcDir });
-	const nodeEnv = process.env.NODE_ENV;
 	const tempConfigServer: ViteDevServer = await createServer({
 		root: fileURLToPath(settings.config.root),
 		server: { middlewareMode: true, hmr: false },
@@ -207,9 +206,6 @@ export async function loadContentConfig({
 		return new NotFoundError('Failed to resolve content config.');
 	} finally {
 		await tempConfigServer.close();
-		// Reset NODE_ENV to initial value
-		// Vite's `createServer()` sets NODE_ENV to 'development'!
-		process.env.NODE_ENV = nodeEnv;
 	}
 	const config = contentConfigParser.safeParse(unparsedConfig);
 	if (config.success) {
diff --git a/packages/astro/src/core/config/config.ts b/packages/astro/src/core/config/config.ts
index 248ea9117..5be492b40 100644
--- a/packages/astro/src/core/config/config.ts
+++ b/packages/astro/src/core/config/config.ts
@@ -115,7 +115,7 @@ export function resolveRoot(cwd?: string | URL): string {
 }
 
 /** Merge CLI flags & user config object (CLI flags take priority) */
-function mergeCLIFlags(astroConfig: AstroUserConfig, flags: CLIFlags, cmd: string) {
+function mergeCLIFlags(astroConfig: AstroUserConfig, flags: CLIFlags) {
 	astroConfig.server = astroConfig.server || {};
 	astroConfig.markdown = astroConfig.markdown || {};
 	astroConfig.experimental = astroConfig.experimental || {};
@@ -136,6 +136,23 @@ function mergeCLIFlags(astroConfig: AstroUserConfig, flags: CLIFlags, cmd: strin
 	return astroConfig;
 }
 
+async function search(fsMod: typeof fs, root: string) {
+	const paths = [
+		'astro.config.mjs',
+		'astro.config.js',
+		'astro.config.ts',
+		'astro.config.mts',
+		'astro.config.cjs',
+		'astro.config.cts',
+	].map((p) => path.join(root, p));
+
+	for (const file of paths) {
+		if (fsMod.existsSync(file)) {
+			return file;
+		}
+	}
+}
+
 interface LoadConfigOptions {
 	cwd?: string;
 	flags?: Flags;
@@ -147,41 +164,36 @@ interface LoadConfigOptions {
 	fsMod?: typeof fs;
 }
 
+interface ResolveConfigPathOptions {
+	cwd?: string;
+	flags?: Flags;
+	fs: typeof fs;
+}
+
 /**
  * Resolve the file URL of the user's `astro.config.js|cjs|mjs|ts` file
- * Note: currently the same as loadConfig but only returns the `filePath`
- * instead of the resolved config
  */
 export async function resolveConfigPath(
-	configOptions: Pick<LoadConfigOptions, 'cwd' | 'flags'> & { fs: typeof fs }
+	configOptions: ResolveConfigPathOptions
 ): Promise<string | undefined> {
 	const root = resolveRoot(configOptions.cwd);
 	const flags = resolveFlags(configOptions.flags || {});
-	let userConfigPath: string | undefined;
 
+	let userConfigPath: string | undefined;
 	if (flags?.config) {
 		userConfigPath = /^\.*\//.test(flags.config) ? flags.config : `./${flags.config}`;
 		userConfigPath = fileURLToPath(new URL(userConfigPath, `file://${root}/`));
-	}
-
-	// Resolve config file path using Proload
-	// If `userConfigPath` is `undefined`, Proload will search for `astro.config.[cm]?[jt]s`
-	try {
-		const config = await loadConfigWithVite({
-			configPath: userConfigPath,
-			root,
-			fs: configOptions.fs,
-		});
-		return config.filePath;
-	} catch (e) {
-		if (flags.config) {
+		if (!configOptions.fs.existsSync(userConfigPath)) {
 			throw new AstroError({
 				...AstroErrorData.ConfigNotFound,
 				message: AstroErrorData.ConfigNotFound.message(flags.config),
 			});
 		}
-		throw e;
+	} else {
+		userConfigPath = await search(configOptions.fs, root);
 	}
+
+	return userConfigPath;
 }
 
 interface OpenConfigResult {
@@ -261,22 +273,6 @@ async function tryLoadConfig(
 	}
 }
 
-/**
- * Attempt to load an `astro.config.mjs` file
- * @deprecated
- */
-export async function loadConfig(configOptions: LoadConfigOptions): Promise<AstroConfig> {
-	const root = resolveRoot(configOptions.cwd);
-	const flags = resolveFlags(configOptions.flags || {});
-	let userConfig: AstroUserConfig = {};
-
-	const config = await tryLoadConfig(configOptions, root);
-	if (config) {
-		userConfig = config.value;
-	}
-	return resolveConfig(userConfig, root, flags, configOptions.cmd);
-}
-
 /** Attempt to resolve an Astro configuration object. Normalize, validate, and return. */
 export async function resolveConfig(
 	userConfig: AstroUserConfig,
@@ -284,7 +280,7 @@ export async function resolveConfig(
 	flags: CLIFlags = {},
 	cmd: string
 ): Promise<AstroConfig> {
-	const mergedConfig = mergeCLIFlags(userConfig, flags, cmd);
+	const mergedConfig = mergeCLIFlags(userConfig, flags);
 	const validatedConfig = await validateConfig(mergedConfig, root, cmd);
 
 	return validatedConfig;
diff --git a/packages/astro/src/core/config/vite-load.ts b/packages/astro/src/core/config/vite-load.ts
index b512d7fab..1a620ab90 100644
--- a/packages/astro/src/core/config/vite-load.ts
+++ b/packages/astro/src/core/config/vite-load.ts
@@ -1,15 +1,7 @@
 import type fsType from 'fs';
-import npath from 'path';
 import { pathToFileURL } from 'url';
 import * as vite from 'vite';
 import loadFallbackPlugin from '../../vite-plugin-load-fallback/index.js';
-import { AstroError, AstroErrorData } from '../errors/index.js';
-
-// Fallback for legacy
-import load from '@proload/core';
-import loadTypeScript from '@proload/plugin-tsm';
-
-load.use([loadTypeScript]);
 
 export interface ViteLoader {
 	root: string;
@@ -24,8 +16,8 @@ async function createViteLoader(root: string, fs: typeof fsType): Promise<ViteLo
 		appType: 'custom',
 		ssr: {
 			// NOTE: Vite doesn't externalize linked packages by default. During testing locally,
-			// these dependencies trip up Vite's dev SSR transform. In the future, we should
-			// avoid `vite.createServer` and use `loadConfigFromFile` instead.
+			// these dependencies trip up Vite's dev SSR transform. Awaiting upstream feature:
+			// https://github.com/vitejs/vite/pull/10939
 			external: [
 				'@astrojs/tailwind',
 				'@astrojs/mdx',
@@ -43,40 +35,6 @@ async function createViteLoader(root: string, fs: typeof fsType): Promise<ViteLo
 	};
 }
 
-async function stat(fs: typeof fsType, configPath: string, mustExist: boolean): Promise<boolean> {
-	try {
-		await fs.promises.stat(configPath);
-		return true;
-	} catch {
-		if (mustExist) {
-			throw new AstroError({
-				...AstroErrorData.ConfigNotFound,
-				message: AstroErrorData.ConfigNotFound.message(configPath),
-			});
-		}
-		return false;
-	}
-}
-
-async function search(fs: typeof fsType, root: string) {
-	const paths = [
-		'astro.config.mjs',
-		'astro.config.js',
-		'astro.config.ts',
-		'astro.config.mts',
-		'astro.config.cjs',
-		'astro.config.cjs',
-	].map((path) => npath.join(root, path));
-
-	for (const file of paths) {
-		// First verify the file event exists
-		const exists = await stat(fs, file, false);
-		if (exists) {
-			return file;
-		}
-	}
-}
-
 interface LoadConfigWithViteOptions {
 	root: string;
 	configPath: string | undefined;
@@ -91,35 +49,25 @@ export async function loadConfigWithVite({
 	value: Record<string, any>;
 	filePath?: string;
 }> {
-	let file: string;
-	if (configPath) {
-		// Go ahead and check if the file exists and throw if not.
-		await stat(fs, configPath, true);
-		file = configPath;
-	} else {
-		const found = await search(fs, root);
-		if (!found) {
-			// No config file found, return an empty config that will be populated with defaults
-			return {
-				value: {},
-				filePath: undefined,
-			};
-		} else {
-			file = found;
-		}
+	// No config file found, return an empty config that will be populated with defaults
+	if (!configPath) {
+		return {
+			value: {},
+			filePath: undefined,
+		};
 	}
 
 	// Try loading with Node import()
-	if (/\.[cm]?js$/.test(file)) {
+	if (/\.[cm]?js$/.test(configPath)) {
 		try {
-			const config = await import(pathToFileURL(file).toString());
+			const config = await import(pathToFileURL(configPath).toString());
 			return {
 				value: config.default ?? {},
-				filePath: file,
+				filePath: configPath,
 			};
 		} catch {
 			// We do not need to keep the error here because with fallback the error will be rethrown
-			// when/if it fails in Proload.
+			// when/if it fails in Vite.
 		}
 	}
 
@@ -127,22 +75,10 @@ export async function loadConfigWithVite({
 	let loader: ViteLoader | undefined;
 	try {
 		loader = await createViteLoader(root, fs);
-		const mod = await loader.viteServer.ssrLoadModule(file);
+		const mod = await loader.viteServer.ssrLoadModule(configPath);
 		return {
 			value: mod.default ?? {},
-			filePath: file,
-		};
-	} catch {
-		// Try loading with Proload
-		// TODO deprecate - this is only for legacy compatibility
-		const res = await load('astro', {
-			mustExist: true,
-			cwd: root,
-			filePath: file,
-		});
-		return {
-			value: res?.value ?? {},
-			filePath: file,
+			filePath: configPath,
 		};
 	} finally {
 		if (loader) {
diff --git a/packages/astro/test/test-utils.js b/packages/astro/test/test-utils.js
index 8c12799f1..63b79d763 100644
--- a/packages/astro/test/test-utils.js
+++ b/packages/astro/test/test-utils.js
@@ -7,7 +7,7 @@ import stripAnsi from 'strip-ansi';
 import { fileURLToPath } from 'url';
 import { sync } from '../dist/cli/sync/index.js';
 import build from '../dist/core/build/index.js';
-import { loadConfig } from '../dist/core/config/config.js';
+import { openConfig } from '../dist/core/config/config.js';
 import { createSettings } from '../dist/core/config/index.js';
 import dev from '../dist/core/dev/index.js';
 import { nodeLogDestination } from '../dist/core/logger/node.js';
@@ -86,7 +86,11 @@ export async function loadFixture(inlineConfig) {
 	const logging = defaultLogging;
 
 	// Load the config.
-	let config = await loadConfig({ cwd: fileURLToPath(cwd), logging });
+	let { astroConfig: config } = await openConfig({
+		cwd: fileURLToPath(cwd),
+		logging,
+		cmd: 'dev',
+	});
 	config = merge(config, { ...inlineConfig, root: cwd });
 
 	// HACK: the inline config doesn't run through config validation where these normalizations usually occur
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 503231a93..6227a240e 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -397,8 +397,6 @@ importers:
       '@babel/traverse': ^7.18.2
       '@babel/types': ^7.18.4
       '@playwright/test': ^1.22.2
-      '@proload/core': ^0.3.3
-      '@proload/plugin-tsm': ^0.2.1
       '@types/babel__core': ^7.1.19
       '@types/babel__generator': ^7.6.4
       '@types/babel__traverse': ^7.17.1
@@ -496,8 +494,6 @@ importers:
       '@babel/plugin-transform-react-jsx': 7.20.7_@babel+core@7.20.12
       '@babel/traverse': 7.20.12
       '@babel/types': 7.20.7
-      '@proload/core': 0.3.3
-      '@proload/plugin-tsm': 0.2.1_@proload+core@0.3.3
       '@types/babel__core': 7.1.20
       '@types/html-escaper': 3.0.0
       '@types/yargs-parser': 21.0.0
diff --git a/scripts/memory/index.js b/scripts/memory/index.js
index 30cc1c0f2..8eaffb56b 100644
--- a/scripts/memory/index.js
+++ b/scripts/memory/index.js
@@ -1,7 +1,8 @@
 import { fileURLToPath } from 'url';
 import v8 from 'v8';
 import dev from '../../packages/astro/dist/core/dev/index.js';
-import { loadConfig } from '../../packages/astro/dist/core/config.js';
+import { openConfig } from '../../packages/astro/dist/core/config.js';
+import { nodeLogDestination } from '../../packages/astro/dist/core/logger/node.js';
 import prettyBytes from 'pretty-bytes';
 
 if (!global.gc) {
@@ -14,8 +15,13 @@ const isCI = process.argv.includes('--ci');
 /** URL directory containing the entire project. */
 const projDir = new URL('./project/', import.meta.url);
 
-let config = await loadConfig({
+let { astroConfig: config } = await openConfig({
 	cwd: fileURLToPath(projDir),
+	logging: {
+		dest: nodeLogDestination,
+		level: 'error',
+	},
+	cmd: 'dev',
 });
 
 const telemetry = {