feat: add runes mode indicator (#2554)

adds a runes mode indicator atop of the file via a code lens. Will show "runes mode" if the components is in that mode, "legacy mode" if not, and nothing if it's not Svelte 5

#2418

Author: dummdidumm

packages/language-server/src/plugins/svelte/SvelteDocument.ts

@@ -48,6 +48,9 @@ export class SvelteDocument {
     public get config() {
         return this.parent.configPromise;
     }
+    public get isSvelte5() {
+        return this.getSvelteVersion()[0] > 4;
+    }
 
     constructor(private parent: Document) {
         this.script = this.parent.scriptInfo;
@@ -70,11 +73,7 @@ export class SvelteDocument {
 
     async getTranspiled(): Promise<ITranspiledSvelteDocument> {
         if (!this.transpiledDoc) {
-            if (!this.svelteVersion) {
-                const { major, minor } = getPackageInfo('svelte', this.getFilePath()).version;
-                this.svelteVersion = [major, minor];
-            }
-            const [major, minor] = this.svelteVersion;
+            const [major, minor] = this.getSvelteVersion();
 
             if (major > 3 || (major === 3 && minor >= 32)) {
                 this.transpiledDoc = await TranspiledSvelteDocument.create(
@@ -103,6 +102,14 @@ export class SvelteDocument {
         const svelte = importSvelte(this.getFilePath());
         return svelte.compile((await this.getTranspiled()).getText(), options);
     }
+
+    private getSvelteVersion() {
+        if (!this.svelteVersion) {
+            const { major, minor } = getPackageInfo('svelte', this.getFilePath()).version;
+            this.svelteVersion = [major, minor];
+        }
+        return this.svelteVersion;
+    }
 }
 
 export interface ITranspiledSvelteDocument extends PositionMapper {

packages/language-server/src/plugins/svelte/SveltePlugin.ts

@@ -3,6 +3,7 @@ import {
     CancellationToken,
     CodeAction,
     CodeActionContext,
+    CodeLens,
     CompletionContext,
     CompletionList,
     Diagnostic,
@@ -49,6 +50,45 @@ export class SveltePlugin
 
     constructor(private configManager: LSConfigManager) {}
 
+    async getCodeLens(document: Document): Promise<CodeLens[] | null> {
+        const doc = await this.getSvelteDoc(document);
+        if (!doc.isSvelte5) return null;
+
+        try {
+            const result = await doc.getCompiled();
+            // @ts-ignore
+            const runes = result.metadata.runes as boolean;
+
+            return [
+                {
+                    range: {
+                        start: { line: 0, character: 0 },
+                        end: { line: 0, character: 0 }
+                    },
+                    command: {
+                        title: runes ? 'Runes mode' : 'Legacy mode',
+                        command: 'svelte.openLink',
+                        arguments: ['https://svelte.dev/docs/svelte/legacy-overview']
+                    }
+                }
+            ];
+        } catch (e) {
+            // show an empty code lens in case of a compilation error to prevent code from jumping around
+            return [
+                {
+                    range: {
+                        start: { line: 0, character: 0 },
+                        end: { line: 0, character: 0 }
+                    },
+                    command: {
+                        title: '',
+                        command: ''
+                    }
+                }
+            ];
+        }
+    }
+
     async getDiagnostics(
         document: Document,
         cancellationToken?: CancellationToken

packages/svelte-vscode/src/extension.ts

@@ -261,6 +261,8 @@ export function activateSvelteLanguageServer(context: ExtensionContext) {
 
     addMigrateToSvelte5Command(getLS, context);
 
+    addOpenLinkCommand(context);
+
     languages.setLanguageConfiguration('svelte', {
         indentationRules: {
             // Matches a valid opening tag that is:
@@ -513,6 +515,14 @@ function addMigrateToSvelte5Command(getLS: () => LanguageClient, context: Extens
     );
 }
 
+function addOpenLinkCommand(context: ExtensionContext) {
+    context.subscriptions.push(
+        commands.registerCommand('svelte.openLink', (url: string) => {
+            commands.executeCommand('vscode.open', Uri.parse(url));
+        })
+    );
+}
+
 function createLanguageServer(serverOptions: ServerOptions, clientOptions: LanguageClientOptions) {
     return new LanguageClient('svelte', 'Svelte', serverOptions, clientOptions);
 }