Allow defineConfig to resolve multiple configs

Author: porada

src/define-config/index.test.ts

@@ -10,7 +10,7 @@ test('defines a valid Oxlint config', () => {
 
 	expect(config).toHaveProperty('rules', expect.any(Object));
 	expect(config.rules).toHaveProperty('unicorn/no-null', 'off');
-	expect(config.rules).not.toHaveProperty('react/jsx-filename-extension');
+	expect(config.rules).not.toHaveProperty('react/jsx-key');
 
 	config = defineConfig({
 		ignorePatterns: ['fixtures/**'],
@@ -24,7 +24,33 @@ test('defines a valid Oxlint config', () => {
 	expect(config.ignorePatterns).toContain('fixtures/**');
 	expect(config).toHaveProperty('rules', expect.any(Object));
 	expect(config.rules).toHaveProperty('unicorn/no-null', 'error');
-	expect(config.rules).not.toHaveProperty('react/jsx-filename-extension');
+	expect(config.rules).not.toHaveProperty('react/jsx-key');
+
+	config = defineConfig(
+		{
+			rules: {
+				'unicorn/no-null': 'warn',
+				'unicorn/no-useless-undefined': 'error',
+			},
+		},
+		{
+			ignorePatterns: ['fixtures/**'],
+			rules: {
+				'unicorn/no-null': 'error',
+			},
+		}
+	);
+
+	expectTypeOf(config).toEqualTypeOf<OxlintConfig>();
+	expect(config).toHaveProperty('ignorePatterns', expect.any(Array));
+	expect(config.ignorePatterns).toContain('fixtures/**');
+	expect(config).toHaveProperty('rules', expect.any(Object));
+	expect(config.rules).toHaveProperty('unicorn/no-null', 'error');
+	expect(config.rules).toHaveProperty(
+		'unicorn/no-useless-undefined',
+		'error'
+	);
+	expect(config.rules).not.toHaveProperty('react/jsx-key');
 });
 
 test('supports the `react` option', () => {
@@ -36,5 +62,10 @@ test('supports the `react` option', () => {
 	expect(config).not.toStrictEqual(defineConfig());
 	expect(config).not.toHaveProperty('react');
 	expect(config.rules).toHaveProperty('unicorn/no-null', 'off');
-	expect(config.rules).toHaveProperty('react/jsx-filename-extension');
+	expect(config.rules).toHaveProperty('react/jsx-key');
+
+	expect(defineConfig({}, { react: true }, {})).toStrictEqual(config);
+	expect(defineConfig({}, { react: true }, { react: false })).toStrictEqual(
+		defineConfig()
+	);
 });

src/define-config/index.ts

@@ -9,12 +9,26 @@ import configTypeDefinitions from '../config-type-definitions/index.ts';
 import mergeConfig from '../merge-config/index.ts';
 
 export default function defineConfig(
-	config: StandardConfig = {}
+	...configs: ReadonlyArray<StandardConfig>
 ): OxlintConfig {
-	const { react, ...extensionConfig } = config;
+	let extensionConfig: OxlintConfig = {};
+	let includeReactConfig = false;
+
+	for (const config of configs) {
+		const { react, ...otherConfig } = config;
+
+		extensionConfig = mergeConfig(extensionConfig, otherConfig);
+
+		if (react !== undefined) {
+			includeReactConfig = react;
+		}
+	}
 
 	const baseConfig: OxlintConfig = {
-		...(react ? mergeConfig(configBase, configReact) : configBase),
+		...(includeReactConfig
+			? mergeConfig(configBase, configReact)
+			: configBase),
+
 		overrides: [
 			{
 				files: [