fix: version range handling in update_pkg function

.changeset/silly-donkeys-shout.md

@@ -0,0 +1,5 @@
+---
+"svelte-migrate": patch
+---
+
+fix: don't downgrade versions when bumping dependencies

packages/migrate/README.md

@@ -3,6 +3,7 @@
 A CLI for migrating Svelte(Kit) codebases.
 
 Run it using
+
 ```
 npx svelte-migrate [migration]
 ```

packages/migrate/migrations/package/migrate_pkg.js

@@ -34,10 +34,10 @@ function analyze(config, file) {
 	const dest = svelte_extension
 		? name.slice(0, -svelte_extension.length) + '.svelte'
 		: name.endsWith('.d.ts')
-		? name
-		: name.endsWith('.ts')
-		? name.slice(0, -3) + '.js'
-		: name;
+			? name
+			: name.endsWith('.ts')
+				? name.slice(0, -3) + '.js'
+				: name;
 
 	return {
 		name,

packages/migrate/migrations/routes/migrate_page_js/index.js

@@ -90,8 +90,8 @@ export function migrate_page(content, filename) {
 							const message = is_string_like(nodes.error)
 								? nodes.error.getText()
 								: is_new(nodes.error, 'Error')
-								? /** @type {string | undefined} */ (nodes.error.arguments[0]?.getText())
-								: false;
+									? /** @type {string | undefined} */ (nodes.error.arguments[0]?.getText())
+									: false;
 
 							if (message !== false) {
 								automigration(

packages/migrate/migrations/routes/migrate_page_server/index.js

@@ -46,8 +46,8 @@ export function migrate_page_server(content, filename) {
 	const load_name = match?.[3]
 		? `LayoutServerLoad.${match[3]}`
 		: match?.[2]
-		? 'LayoutServerLoad'
-		: 'PageServerLoad';
+			? 'LayoutServerLoad'
+			: 'PageServerLoad';
 
 	const has_load = file.exports.map.has('GET');
 	const has_action = non_get_methods.some((method) => file.exports.map.has(method));

packages/migrate/migrations/routes/migrate_server/index.js

@@ -147,7 +147,7 @@ export function migrate_server(content) {
 								init.length > 0
 									? `new Response(${body}, {${join_whitespace}${init.join(
 											`,${join_whitespace}`
-									  )}${end_whitespace}})`
+										)}${end_whitespace}})`
 									: `new Response(${body})`;
 
 							if (safe_body) {

packages/migrate/migrations/svelte-4/migrate.spec.js

@@ -363,7 +363,6 @@ test('Update package.json', () => {
 	);
 });
 
-
 test('Does not downgrade versions', () => {
 	const result = update_pkg_json_content(`{
 	"devDependencies": {

packages/migrate/package.json

@@ -41,6 +41,8 @@
 	},
 	"scripts": {
 		"test": "vitest run --silent",
-		"check": "tsc"
+		"check": "tsc",
+		"lint": "prettier --check .",
+		"format": "pnpm lint --write"
 	}
 }

packages/migrate/utils.js

@@ -215,23 +215,30 @@ export function update_pkg(content, updates) {
 	 * @param {'dependencies' | 'devDependencies' | undefined} [insert]
 	 */
 	function update_pkg(name, version, additional = '', insert) {
-		if (pkg.dependencies?.[name]) {
-			const existing_range = pkg.dependencies[name];
-
-			if (semver.validRange(existing_range) && !semver.subset(existing_range, version)) {
-				log_migration(`Updated ${name} to ${version} ${additional}`);
-				pkg.dependencies[name] = version;
+		/**
+		 * @param {string} type
+		 */
+		const updateVersion = (type) => {
+			const existingRange = pkg[type]?.[name];
+
+			if (
+				existingRange &&
+				semver.validRange(existingRange) &&
+				!semver.subset(existingRange, version)
+			) {
+				// Check if the new version range is an upgrade
+				const minExistingVersion = semver.minVersion(existingRange);
+				const minNewVersion = semver.minVersion(version);
+
+				if (minExistingVersion && minNewVersion && semver.gt(minNewVersion, minExistingVersion)) {
+					log_migration(`Updated ${name} to ${version}`);
+					pkg[type][name] = version;
+				}
 			}
-		}
-
-		if (pkg.devDependencies?.[name]) {
-			const existing_range = pkg.devDependencies[name];
+		};
 
-			if (semver.validRange(existing_range) && !semver.subset(existing_range, version)) {
-				log_migration(`Updated ${name} to ${version} ${additional}`);
-				pkg.devDependencies[name] = version;
-			}
-		}
+		updateVersion('dependencies');
+		updateVersion('devDependencies');
 
 		if (insert && !pkg[insert]?.[name]) {
 			if (!pkg[insert]) pkg[insert] = {};

packages/migrate/utils.spec.js

@@ -1,73 +1,93 @@
-import { assert, test } from 'vitest';
-import { update_pkg } from './utils.js';
-
-test('Inserts package at correct position (1)', () => {
-	const result = update_pkg(
-		`{
-	"dependencies": {
-		"a": "1",
-		"z": "3",
-		"c": "4"
-	}
-}`,
-		[['b', '2', '', 'dependencies']]
-	);
-
-	assert.equal(
-		result,
-		`{
-	"dependencies": {
-		"a": "1",
-		"b": "2",
-		"z": "3",
-		"c": "4"
-	}
-}`
-	);
-});
-
-test('Inserts package at correct position (2)', () => {
-	const result = update_pkg(
-		`{
-	"dependencies": {
-		"a": "1",
-		"b": "2"
-	}
-}`,
-		[['c', '3', '', 'dependencies']]
-	);
-
-	assert.equal(
-		result,
-		`{
-	"dependencies": {
-		"a": "1",
-		"b": "2",
-		"c": "3"
-	}
-}`
-	);
-});
-
-test('Inserts package at correct position (3)', () => {
-	const result = update_pkg(
-		`{
-	"dependencies": {
-		"b": "2",
-		"c": "3"
-	}
-}`,
-		[['a', '1', '', 'dependencies']]
-	);
-
-	assert.equal(
-		result,
-		`{
-	"dependencies": {
-		"a": "1",
-		"b": "2",
-		"c": "3"
-	}
-}`
-	);
-});
+import { assert, test } from 'vitest';
+import { update_pkg } from './utils.js';
+
+test('Inserts package at correct position (1)', () => {
+	const result = update_pkg(
+		`{
+	"dependencies": {
+		"a": "1",
+		"z": "3",
+		"c": "4"
+	}
+}`,
+		[['b', '2', '', 'dependencies']]
+	);
+
+	assert.equal(
+		result,
+		`{
+	"dependencies": {
+		"a": "1",
+		"b": "2",
+		"z": "3",
+		"c": "4"
+	}
+}`
+	);
+});
+
+test('Inserts package at correct position (2)', () => {
+	const result = update_pkg(
+		`{
+	"dependencies": {
+		"a": "1",
+		"b": "2"
+	}
+}`,
+		[['c', '3', '', 'dependencies']]
+	);
+
+	assert.equal(
+		result,
+		`{
+	"dependencies": {
+		"a": "1",
+		"b": "2",
+		"c": "3"
+	}
+}`
+	);
+});
+
+test('Inserts package at correct position (3)', () => {
+	const result = update_pkg(
+		`{
+	"dependencies": {
+		"b": "2",
+		"c": "3"
+	}
+}`,
+		[['a', '1', '', 'dependencies']]
+	);
+
+	assert.equal(
+		result,
+		`{
+	"dependencies": {
+		"a": "1",
+		"b": "2",
+		"c": "3"
+	}
+}`
+	);
+});
+
+test('Does not downgrade versions', () => {
+	const result = update_pkg(
+		`{
+	"devDependencies": {
+		"@sveltejs/kit": "^2.4.3"
+	}
+}`,
+		[['@sveltejs/kit', '^2.0.0']]
+	);
+
+	assert.equal(
+		result,
+		`{
+	"devDependencies": {
+		"@sveltejs/kit": "^2.4.3"
+	}
+}`
+	);
+});