refactor: Make config file handling consistent

packages/cli/lib/lib/webpack/render-html-plugin.js

@@ -5,7 +5,7 @@ const HtmlWebpackExcludeAssetsPlugin = require('html-webpack-exclude-assets-plug
 const HtmlWebpackPlugin = require('html-webpack-plugin');
 const prerender = require('./prerender');
 const createLoadManifest = require('./create-load-manifest');
-const { esmImport, warn } = require('../../util');
+const { esmImport, tryResolveConfig, warn } = require('../../util');
 
 const PREACT_FALLBACK_URL = '/200.html';
 
@@ -106,9 +106,16 @@ module.exports = async function (config) {
 	let pages = [{ url: '/' }];
 
 	if (config.prerenderUrls) {
-		if (existsSync(resolve(cwd, config.prerenderUrls))) {
+		const prerenderUrls = tryResolveConfig(
+			cwd,
+			config.prerenderUrls,
+			config.prerenderUrls === 'prerender-urls.json',
+			config.verbose
+		);
+
+		if (prerenderUrls) {
 			try {
-				let result = esmImport(resolve(cwd, config.prerenderUrls));
+				let result = esmImport(prerenderUrls);
 
 				if (typeof result.default !== 'undefined') {
 					result = result.default;
@@ -129,17 +136,6 @@ module.exports = async function (config) {
 					}`
 				);
 			}
-			// don't warn if the default file doesn't exist
-		} else if (
-			config.prerenderUrls !== 'prerender-urls.json' ||
-			config.verbose
-		) {
-			warn(
-				`prerenderUrls file (${resolve(
-					cwd,
-					config.prerenderUrls
-				)}) doesn't exist, using default!`
-			);
 		}
 	}
 	/**

packages/cli/lib/lib/webpack/transform-config.js

@@ -1,7 +1,7 @@
 const { resolve } = require('path');
 const webpack = require('webpack');
 const { stat } = require('fs').promises;
-const { error, esmImport } = require('../../util');
+const { error, esmImport, tryResolveConfig, warn } = require('../../util');
 
 const FILE = 'preact.config';
 const EXTENSIONS = ['js', 'json'];
@@ -95,27 +95,26 @@ module.exports = async function (env, webpackConfig, isServer = false) {
 		env.config !== 'preact.config.js'
 			? { configFile: env.config, isDefault: false }
 			: await findConfig(env);
-	env.config = configFile;
-	let myConfig = resolve(env.cwd, env.config);
+
+	const cliConfig = tryResolveConfig(
+		env.cwd,
+		configFile,
+		isDefault,
+		env.verbose
+	);
+
+	if (!cliConfig) return;
 
 	let m;
 	try {
-		m = esmImport(myConfig);
-	} catch (err) {
-		const notFound =
-			err.message.includes('Cannot find module') ||
-			err.message.includes('Qualified path resolution failed');
-		if (notFound && isDefault) return;
-		if (notFound) {
-			throw new Error(
-				`Failed to load preact-cli config!\nFile ${env.config} not found.\n`
-			);
-		}
-		throw new Error(
-			`Failed to load preact-cli config!\n${
-				env.verbose ? err.stack : err.message
-			}\n`
+		m = esmImport(cliConfig);
+	} catch (error) {
+		warn(
+			`Failed to load preact-cli config file, using default!\n${
+				env.verbose ? error.stack : error.message
+			}`
 		);
+		return;
 	}
 
 	const transformers = parseConfig((m && m.default) || m);
@@ -134,7 +133,7 @@ module.exports = async function (env, webpackConfig, isServer = false) {
 				options
 			);
 		} catch (err) {
-			throw new Error((`Error at ${myConfig}: \n` + err && err.stack) || err);
+			throw new Error((`Error at ${cliConfig}: \n` + err && err.stack) || err);
 		}
 	}
 };

packages/cli/lib/util.js

@@ -30,10 +30,10 @@ exports.info = function (text, code) {
 	code && process.exit(code);
 };
 
-exports.warn = function (text, code) {
+const warn = (exports.warn = function (text, code) {
 	process.stdout.write(symbols.warning + yellow(' WARN ') + text + '\n');
 	code && process.exit(code);
-};
+});
 
 exports.error = function (text, code = 1) {
 	process.stderr.write(symbols.error + red(' ERROR ') + text + '\n');
@@ -80,3 +80,12 @@ exports.isPortFree = async function (port) {
 		return false;
 	}
 };
+
+exports.tryResolveConfig = function (cwd, file, isDefault, verbose) {
+	const path = resolve(cwd, file);
+	if (existsSync(path)) {
+		return path;
+	} else if (!isDefault || verbose) {
+		warn(`${resolve(cwd, file)} doesn't exist, using default!`);
+	}
+};

packages/cli/tests/config.test.js

@@ -55,9 +55,17 @@ describe('config files', () => {
 				it(`should load the '${dataFormat}' file in ${moduleFormat}`, async () => {
 					let dir = await subject('multiple-config-files');
 
-					await expect(
-						build(dir, { config: `preactConfig/${moduleFormat}/${dataFormat}` })
-					).resolves.not.toThrow();
+					const logSpy = jest.spyOn(process.stdout, 'write');
+
+					await build(dir, {
+						config: `preactConfig/${moduleFormat}/${dataFormat}`,
+					});
+
+					expect(logSpy).not.toHaveBeenCalledWith(
+						expect.stringContaining(
+							'Failed to load preact-cli config file, using default!'
+						)
+					);
 				});
 			});
 		});