fix: dont emit false positive export condition warning

fixes #9097

.changeset/friendly-pandas-sort.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/package': patch
+---
+
+fix: dont emit false positive export condition warning

packages/package/src/validate.js

@@ -1,10 +1,46 @@
-import { existsSync, readFileSync } from 'node:fs';
+import { readFileSync } from 'node:fs';
+import { join } from 'node:path';
 import colors from 'kleur';
 
 /**
  * @param {import("./types").Options} options
  */
 export function create_validator(options) {
+	const { analyse_code, validate } = _create_validator(options);
+
+	return {
+		/**
+		 * Checks a file content for problematic imports and things like `import.meta`
+		 * @param {string} name
+		 * @param {string} content
+		 */
+		analyse_code(name, content) {
+			analyse_code(name, content);
+		},
+		validate() {
+			/** @type {Record<string, any>} */
+			const pkg = JSON.parse(readFileSync(join(options.cwd, 'package.json'), 'utf-8'));
+			const warnings = validate(pkg);
+			// Just warnings, not errors, because
+			// - would be annoying in watch mode (would have to restart the server)
+			// - maybe there's a custom post-build script that fixes some of these
+			if (warnings.length) {
+				console.log(
+					colors
+						.bold()
+						.yellow('@sveltejs/package found the following issues while packaging your library:')
+				);
+				for (const warning of warnings) {
+					console.log(colors.yellow(`${warning}\n`));
+				}
+			}
+		}
+	};
+}
+/**
+ * @param {import("./types").Options} options
+ */
+export function _create_validator(options) {
 	/** @type {Set<string>} */
 	const imports = new Set();
 	let uses_import_meta = false;
@@ -32,9 +68,10 @@ export function create_validator(options) {
 		}
 	}
 
-	function validate() {
-		/** @type {Record<string, any>} */
-		const pkg = JSON.parse(readFileSync('package.json', 'utf-8'));
+	/**
+	 * @param {Record<string, any>} pkg
+	 */
+	function validate(pkg) {
 		/** @type {string[]} */
 		const warnings = [];
 
@@ -109,19 +146,7 @@ export function create_validator(options) {
 			);
 		}
 
-		// Just warnings, not errors, because
-		// - would be annoying in watch mode (would have to restart the server)
-		// - maybe there's a custom post-build script that fixes some of these
-		if (warnings.length) {
-			console.log(
-				colors
-					.bold()
-					.yellow('@sveltejs/package found the following issues while packaging your library:')
-			);
-			for (const warning of warnings) {
-				console.log(colors.yellow(`${warning}\n`));
-			}
-		}
+		return warnings;
 	}
 
 	return {
@@ -146,7 +171,7 @@ function traverse_exports(exports_map) {
 	 */
 	function traverse(exports_map, is_first_level) {
 		for (const key of Object.keys(exports_map ?? {})) {
-			if (is_first_level) {
+			if (!is_first_level) {
 				conditions.add(key);
 			}
 

packages/package/test/fixtures/assets/package.json

@@ -2,5 +2,14 @@
 	"name": "assets",
 	"private": true,
 	"version": "1.0.0",
-	"description": "no tampering assets"
+	"description": "no tampering assets",
+	"peerDependencies": {
+		"svelte": "^3.55.0"
+	},
+	"exports": {
+		".": {
+			"types": "./dist/index.d.ts",
+			"svelte": "./dist/index.js"
+		}
+	}
 }

packages/package/test/fixtures/emitTypes-false/package.json

@@ -3,5 +3,13 @@
 	"private": true,
 	"version": "1.0.0",
 	"description": "emitTypes settings disabled",
-	"type": "module"
+	"type": "module",
+	"peerDependencies": {
+		"svelte": "^3.55.0"
+	},
+	"exports": {
+		".": {
+			"svelte": "./dist/index.js"
+		}
+	}
 }

packages/package/test/fixtures/javascript/package.json

@@ -2,5 +2,14 @@
 	"name": "javascript",
 	"private": true,
 	"version": "1.0.0",
-	"description": "standard javascript package"
+	"description": "standard javascript package",
+	"peerDependencies": {
+		"svelte": "^3.55.0"
+	},
+	"exports": {
+		".": {
+			"types": "./dist/index.d.ts",
+			"svelte": "./dist/index.js"
+		}
+	}
 }

packages/package/test/fixtures/resolve-alias/package.json

@@ -3,5 +3,14 @@
 	"private": true,
 	"version": "1.0.0",
 	"description": "package using $lib alias",
-	"type": "module"
+	"type": "module",
+	"peerDependencies": {
+		"svelte": "^3.55.0"
+	},
+	"exports": {
+		".": {
+			"types": "./dist/index.d.ts",
+			"svelte": "./dist/index.js"
+		}
+	}
 }

packages/package/test/fixtures/svelte-kit/package.json

@@ -3,5 +3,14 @@
 	"private": true,
 	"version": "1.0.0",
 	"type": "module",
-	"description": "SvelteKit library project"
+	"description": "SvelteKit library project",
+	"peerDependencies": {
+		"svelte": "^3.55.0"
+	},
+	"exports": {
+		".": {
+			"types": "./dist/index.d.ts",
+			"svelte": "./dist/index.js"
+		}
+	}
 }

packages/package/test/fixtures/typescript/package.json

@@ -3,5 +3,14 @@
 	"private": true,
 	"version": "1.0.0",
 	"description": "standard typescript package",
-	"type": "module"
+	"type": "module",
+	"peerDependencies": {
+		"svelte": "^3.55.0"
+	},
+	"exports": {
+		".": {
+			"types": "./dist/index.d.ts",
+			"svelte": "./dist/index.js"
+		}
+	}
 }

packages/package/test/index.js

@@ -9,6 +9,7 @@ import * as assert from 'uvu/assert';
 import { build, watch } from '../src/index.js';
 import { load_config } from '../src/config.js';
 import { rimraf, walk } from '../src/filesystem.js';
+import { _create_validator } from '../src/validate.js';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = join(__filename, '..');
@@ -214,4 +215,89 @@ if (!process.env.CI) {
 	});
 }
 
+/**
+ * @param {string[]} actual
+ * @param {string[]} expected
+ */
+function has_warnings(actual, expected) {
+	assert.equal(actual.length, expected.length);
+	assert.equal(
+		actual.filter((warning) => expected.some((str) => warning.startsWith(str))).length,
+		expected.length
+	);
+}
+
+test('validates package (1)', () => {
+	const { analyse_code, validate } = _create_validator({
+		config: {},
+		cwd: '',
+		input: '',
+		output: '',
+		types: true
+	});
+	analyse_code('src/lib/index.js', 'export const a = 1;import.meta.env;');
+	analyse_code('src/lib/C.svelte', '');
+	const warnings = validate({});
+
+	has_warnings(warnings, [
+		'No `exports` field found in `package.json`, please provide one.',
+		'Avoid usage of `import.meta.env` in your code',
+		'You are using Svelte components or Svelte-specific imports in your code, but you have not declared a dependency on `svelte` in your `package.json`. '
+	]);
+});
+
+test('validates package (2)', () => {
+	const { analyse_code, validate } = _create_validator({
+		config: {},
+		cwd: '',
+		input: '',
+		output: '',
+		types: true
+	});
+	analyse_code('src/lib/C.svelte', '');
+	const warnings = validate({
+		exports: { '.': './dist/C.svelte' },
+		peerDependencies: { svelte: '^3.55.0' }
+	});
+
+	has_warnings(warnings, [
+		'You are using Svelte files, but did not declare a `svelte` condition in one of your `exports` in your `package.json`. '
+	]);
+});
+
+test('validates package (all ok 1)', () => {
+	const { analyse_code, validate } = _create_validator({
+		config: {},
+		cwd: '',
+		input: '',
+		output: '',
+		types: true
+	});
+	analyse_code('src/lib/C.svelte', '');
+	const warnings = validate({
+		exports: { '.': { svelte: './dist/C.svelte' } },
+		peerDependencies: { svelte: '^3.55.0' }
+	});
+
+	assert.equal(warnings.length, 0);
+});
+
+test('validates package (all ok 2)', () => {
+	const { analyse_code, validate } = _create_validator({
+		config: {},
+		cwd: '',
+		input: '',
+		output: '',
+		types: true
+	});
+	analyse_code('src/lib/C.svelte', '');
+	const warnings = validate({
+		exports: { '.': { svelte: './dist/C.svelte' } },
+		peerDependencies: { svelte: '^3.55.0' },
+		svelte: './dist/C.svelte'
+	});
+
+	assert.equal(warnings.length, 0);
+});
+
 test.run();

packages/package/test/watch/package.json

@@ -1,4 +1,13 @@
 {
 	"name": "watch",
-	"type": "module"
+	"type": "module",
+	"peerDependencies": {
+		"svelte": "^3.55.0"
+	},
+	"exports": {
+		".": {
+			"types": "./dist/index.d.ts",
+			"svelte": "./dist/index.js"
+		}
+	}
 }