chore: configure knip (#13016)

* chore: configure knip

* bump vitest

* ok prettier

* remove some unused warnings

* ugh computers are the worst

* just shut up

Author: Rich-Harris

Diff for: packages/svelte/knip.json

@@ -0,0 +1,18 @@
+{
+	"$schema": "https://unpkg.com/knip@5/schema.json",
+	"entry": [
+		"src/*/index.js",
+		"src/index-client.ts",
+		"src/index-server.ts",
+		"src/index.d.ts",
+		"tests/**/*.js",
+		"tests/**/*.ts",
+		"!tests/**/*.svelte",
+		"!tests/**/*.svelte.js",
+		"!tests/**/_output",
+		"!tests/runtime-browser/driver.js",
+		"!tests/runtime-browser/driver-ssr.js",
+		"!tests/types/component.ts"
+	],
+	"project": ["src/**"]
+}

Diff for: packages/svelte/messages/client-errors/errors.md

@@ -79,7 +79,3 @@
 ## state_unsafe_mutation
 
 > Updating state inside a derived is forbidden. If the value should not be reactive, declare it without `$state`
-
-## svelte_component_invalid_this_value
-
-> The `this={...}` property of a `<svelte:component>` must be a Svelte component, if defined

Diff for: packages/svelte/messages/compile-errors/template.md

@@ -302,10 +302,6 @@ HTML restricts where certain elements can appear. In case of a violation the bro
 
 > `<svelte:fragment>` must be the direct child of a component
 
-## svelte_fragment_invalid_slot
-
-> `<svelte:fragment>` slot attribute must have a static value
-
 ## svelte_head_illegal_attribute
 
 > `<svelte:head>` cannot have attributes nor directives

Diff for: packages/svelte/messages/compile-warnings/script.md

@@ -1,7 +1,3 @@
-## derived_iife
-
-> Use `$derived.by(() => {...})` instead of `$derived((() => {...})())`
-
 ## export_let_unused
 
 > Component has unused export property '%name%'. If it is for external reference only, please consider using `export const %name%`

Diff for: packages/svelte/package.json

@@ -124,11 +124,16 @@
     "@rollup/plugin-terser": "^0.4.4",
     "@rollup/plugin-virtual": "^3.0.2",
     "@types/aria-query": "^5.0.4",
+    "@types/node": "^20.11.5",
     "dts-buddy": "^0.5.1",
     "esbuild": "^0.19.11",
+    "eslint": "^9.6.0",
+    "prettier": "^3.2.4",
     "rollup": "^4.9.5",
     "source-map": "^0.7.4",
-    "tiny-glob": "^0.2.9"
+    "tiny-glob": "^0.2.9",
+    "typescript": "^5.5.2",
+    "vitest": "^1.2.1"
   },
   "dependencies": {
     "@ampproject/remapping": "^2.2.1",
@@ -144,18 +149,5 @@
     "locate-character": "^3.0.0",
     "magic-string": "^0.30.5",
     "zimmerframe": "^1.1.2"
-  },
-  "knip": {
-    "entry": [
-      "src/*/index.js",
-      "src/index-client.ts",
-      "src/index-server.ts",
-      "src/index.d.ts",
-      "tests/**/*.js",
-      "tests/**/*.ts"
-    ],
-    "project": [
-      "src/**"
-    ]
   }
 }

Diff for: packages/svelte/src/compiler/errors.js

@@ -1246,15 +1246,6 @@ export function svelte_fragment_invalid_placement(node) {
 	e(node, "svelte_fragment_invalid_placement", "`<svelte:fragment>` must be the direct child of a component");
 }
 
-/**
- * `<svelte:fragment>` slot attribute must have a static value
- * @param {null | number | NodeLike} node
- * @returns {never}
- */
-export function svelte_fragment_invalid_slot(node) {
-	e(node, "svelte_fragment_invalid_slot", "`<svelte:fragment>` slot attribute must have a static value");
-}
-
 /**
  * `<svelte:head>` cannot have attributes nor directives
  * @param {null | number | NodeLike} node

Diff for: packages/svelte/src/compiler/warnings.js

@@ -94,7 +94,6 @@ export const codes = [
 	"options_removed_hydratable",
 	"options_removed_loop_guard_timeout",
 	"options_renamed_ssr_dom",
-	"derived_iife",
 	"export_let_unused",
 	"legacy_component_creation",
 	"non_reactive_update",
@@ -574,14 +573,6 @@ export function options_renamed_ssr_dom(node) {
 	w(node, "options_renamed_ssr_dom", "`generate: \"dom\"` and `generate: \"ssr\"` options have been renamed to \"client\" and \"server\" respectively");
 }
 
-/**
- * Use `$derived.by(() => {...})` instead of `$derived((() => {...})())`
- * @param {null | NodeLike} node
- */
-export function derived_iife(node) {
-	w(node, "derived_iife", "Use `$derived.by(() => {...})` instead of `$derived((() => {...})())`");
-}
-
 /**
  * Component has unused export property '%name%'. If it is for external reference only, please consider using `export const %name%`
  * @param {null | NodeLike} node

Diff for: packages/svelte/src/internal/client/errors.js

@@ -340,20 +340,4 @@ export function state_unsafe_mutation() {
 		// TODO print a link to the documentation
 		throw new Error("state_unsafe_mutation");
 	}
-}
-
-/**
- * The `this={...}` property of a `<svelte:component>` must be a Svelte component, if defined
- * @returns {never}
- */
-export function svelte_component_invalid_this_value() {
-	if (DEV) {
-		const error = new Error(`svelte_component_invalid_this_value\nThe \`this={...}\` property of a \`<svelte:component>\` must be a Svelte component, if defined`);
-
-		error.name = 'Svelte error';
-		throw error;
-	} else {
-		// TODO print a link to the documentation
-		throw new Error("svelte_component_invalid_this_value");
-	}
 }

Diff for: packages/svelte/tests/sourcemaps/samples/markup/test.js

@@ -14,6 +14,7 @@
 		"strict": true,
 		"allowJs": true,
 		"checkJs": true,
+		"skipLibCheck": true,
 		"paths": {
 			"acorn-typescript": ["./src/compiler/phases/1-parse/ambient.d.ts"],
 			"svelte": ["./src/index.d.ts"],