tsgo (#834)

* looking at tsgo

* remove typescript at root! (needed in migrate for now)

Author: jycouet

package.json

@@ -25,6 +25,7 @@
 		"@sveltejs/eslint-config": "^8.3.4",
 		"@svitejs/changesets-changelog-github-compact": "^1.2.0",
 		"@types/node": "^22.19.1",
+		"@typescript/native-preview": "7.0.0-dev.20251204.1",
 		"@vitest/ui": "4.0.7",
 		"eslint": "^9.39.1",
 		"eslint-plugin-svelte": "^3.13.0",
@@ -35,7 +36,6 @@
 		"sv": "workspace:*",
 		"svelte": "^5.43.8",
 		"tsdown": "^0.15.12",
-		"typescript": "^5.9.3",
 		"typescript-eslint": "^8.47.0",
 		"vitest": "4.0.7"
 	},

packages/addons/package.json

@@ -4,7 +4,7 @@
 	"version": "0.0.0",
 	"type": "module",
 	"scripts": {
-		"check": "tsc",
+		"check": "tsgo",
 		"format": "pnpm lint --write",
 		"lint": "prettier --check . --config ../../prettier.config.js --ignore-path ../../.gitignore --ignore-path .gitignore --ignore-path ../../.prettierignore",
 		"test": "vitest run",

packages/cli/package.json

@@ -11,7 +11,7 @@
 	},
 	"homepage": "https://svelte.dev",
 	"scripts": {
-		"check": "tsc",
+		"check": "tsgo",
 		"format": "pnpm lint --write",
 		"lint": "prettier --check . --config ../../prettier.config.js --ignore-path ../../.gitignore --ignore-path .gitignore --ignore-path ../../.prettierignore"
 	},

packages/core/package.json

@@ -11,7 +11,7 @@
 	},
 	"bugs": "https://github.com/sveltejs/cli/issues",
 	"scripts": {
-		"check": "tsc",
+		"check": "tsgo",
 		"format": "pnpm lint --write",
 		"lint": "prettier --check . --config ../../prettier.config.js --ignore-path ../../.gitignore --ignore-path .gitignore --ignore-path ../../.prettierignore",
 		"test": "vitest run",

packages/create/package.json

@@ -13,7 +13,7 @@
 	"homepage": "https://svelte.dev",
 	"scripts": {
 		"build:dist": "node scripts/build-templates dist",
-		"check": "tsc",
+		"check": "tsgo",
 		"format": "pnpm lint --write",
 		"lint": "prettier --check . --config ../../prettier.config.js --ignore-path ../../.gitignore --ignore-path .gitignore --ignore-path ../../.prettierignore",
 		"test": "vitest run",

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

@@ -90,7 +90,7 @@ 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())
+									? /** @type {string | undefined} */ (nodes.error.arguments?.[0]?.getText())
 									: false;
 
 							if (message !== false) {

packages/migrate/migrations/routes/utils.js

@@ -276,7 +276,7 @@ export function unwrap(node) {
 /**
  * @param {ts.Node} node
  * @param {string} name
- * @returns {node is ts.isNewExpression}
+ * @returns {node is ts.NewExpression}
  */
 export function is_new(node, name) {
 	return (

packages/migrate/package.json

@@ -11,7 +11,7 @@
 	},
 	"homepage": "https://svelte.dev",
 	"scripts": {
-		"check": "tsc",
+		"check": "tsgo",
 		"format": "pnpm lint --write",
 		"lint": "prettier --check .",
 		"test": "vitest run"