Fix svelte plugin diagnostic mapping for context="module"

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

@@ -175,11 +175,16 @@ export class SvelteFragmentMapper {
     }
 
     static async createScript(originalDoc: Document, transpiled: string, processed: Processed[]) {
+        const scriptInfo = originalDoc.scriptInfo || originalDoc.moduleScriptInfo;
+        const maybeScriptTag = extractScriptTags(transpiled);
+        const maybeScriptTagInfo =
+            maybeScriptTag && (maybeScriptTag.script || maybeScriptTag.moduleScript);
+
         return SvelteFragmentMapper.create(
             originalDoc,
             transpiled,
-            originalDoc.scriptInfo,
-            extractScriptTags(transpiled)?.script || null,
+            scriptInfo,
+            maybeScriptTagInfo || null,
             processed,
         );
     }

packages/language-server/src/plugins/svelte/features/getDiagnostics.ts

@@ -78,7 +78,10 @@ async function createParserErrorDiagnostic(error: any, document: Document) {
 
     if (diagnostic.message.includes('expected')) {
         const isInStyle = isInTag(diagnostic.range.start, document.styleInfo);
-        const isInScript = isInTag(diagnostic.range.start, document.scriptInfo);
+        const isInScript = isInTag(
+            diagnostic.range.start,
+            document.scriptInfo || document.moduleScriptInfo,
+        );
 
         if (isInStyle || isInScript) {
             diagnostic.message +=

packages/language-server/src/plugins/typescript/DocumentSnapshot.ts

@@ -151,7 +151,8 @@ function preprocessSvelteFile(document: Document, options: SvelteSnapshotOptions
         if (tsxMap) {
             tsxMap.sources = [document.uri];
 
-            const tsCheck = getTsCheckComment(document.scriptInfo?.content);
+            const scriptInfo = document.scriptInfo || document.moduleScriptInfo;
+            const tsCheck = getTsCheckComment(scriptInfo?.content);
             if (tsCheck) {
                 text = tsCheck + text;
                 nrPrependedLines = 1;
@@ -172,7 +173,8 @@ function preprocessSvelteFile(document: Document, options: SvelteSnapshotOptions
         };
 
         // fall back to extracted script, if any
-        text = document.scriptInfo ? document.scriptInfo.content : '';
+        const scriptInfo = document.scriptInfo || document.moduleScriptInfo;
+        text = scriptInfo ? scriptInfo.content : '';
     }
 
     return {
@@ -330,7 +332,7 @@ export class SvelteSnapshotFragment implements SnapshotFragment {
     ) {}
 
     get scriptInfo() {
-        return this.parent.scriptInfo;
+        return this.parent.scriptInfo || this.parent.moduleScriptInfo;
     }
 
     getOriginalPosition(pos: Position): Position {

packages/language-server/src/plugins/typescript/features/CodeActionsProvider.ts

@@ -55,7 +55,7 @@ export class CodeActionsProviderImpl implements CodeActionsProvider {
     }
 
     private async organizeImports(document: Document): Promise<CodeAction[]> {
-        if (!document.scriptInfo) {
+        if (!document.scriptInfo && !document.moduleScriptInfo) {
             return [];
         }
 

packages/language-server/src/plugins/typescript/features/CompletionProvider.ts

@@ -34,7 +34,7 @@ export interface CompletionEntryWithIdentifer extends ts.CompletionEntry, TextDo
 type validTriggerCharacter = '.' | '"' | "'" | '`' | '/' | '@' | '<' | '#';
 
 export class CompletionsProviderImpl implements CompletionsProvider<CompletionEntryWithIdentifer> {
-    constructor(private readonly lsAndTsDocResolver: LSAndTSDocResolver) { }
+    constructor(private readonly lsAndTsDocResolver: LSAndTSDocResolver) {}
 
     /**
      * The language service throws an error if the character is not a valid trigger character.

packages/language-server/test/plugins/svelte/features/getDiagnostics.test.ts

@@ -1,4 +1,6 @@
 import * as assert from 'assert';
+import * as path from 'path';
+import * as fs from 'fs';
 import { Diagnostic, DiagnosticSeverity, Position } from 'vscode-languageserver';
 import { Document } from '../../../../src/lib/documents';
 import { getDiagnostics } from '../../../../src/plugins/svelte/features/getDiagnostics';
@@ -7,7 +9,9 @@ import {
     TranspileErrorSource,
 } from '../../../../src/plugins/svelte/SvelteDocument';
 import { SvelteConfig } from '../../../../src/lib/documents/configLoader';
-import { CompilerWarningsSettings } from '../../../../src/ls-config';
+import { CompilerWarningsSettings, LSConfigManager } from '../../../../src/ls-config';
+import { pathToUrl } from '../../../../src/utils';
+import { SveltePlugin } from '../../../../src/plugins';
 
 describe('SveltePlugin#getDiagnostics', () => {
     async function expectDiagnosticsFor({
@@ -31,6 +35,15 @@ describe('SveltePlugin#getDiagnostics', () => {
         };
     }
 
+    function setupFromFile(filename: string) {
+        const testDir = path.join(__dirname, '..');
+        const filePath = path.join(testDir, 'testfiles', filename);
+        const document = new Document(pathToUrl(filePath), fs.readFileSync(filePath, 'utf-8'));
+        const pluginManager = new LSConfigManager();
+        const plugin = new SveltePlugin(pluginManager);
+        return { plugin, document };
+    }
+
     it('expect svelte.config.js error', async () => {
         (
             await expectDiagnosticsFor({
@@ -369,4 +382,36 @@ describe('SveltePlugin#getDiagnostics', () => {
             },
         ]);
     });
+
+    it('should correctly determine diagnostic position', async () => {
+        const { plugin, document } = setupFromFile('diagnostics.svelte');
+        const diagnostics = await plugin.getDiagnostics(document);
+
+        assert.deepStrictEqual(diagnostics, [
+            {
+                range: { start: { line: 1, character: 15 }, end: { line: 1, character: 27 } },
+                message:
+                    "Component has unused export property 'name'. If it is for external reference only, please consider using `export const name`",
+                severity: 2,
+                source: 'svelte',
+                code: 'unused-export-let',
+            },
+        ]);
+    });
+
+    it('should correctly determine diagnostic position for context="module"', async () => {
+        const { plugin, document } = setupFromFile('diagnostics-module.svelte');
+        const diagnostics = await plugin.getDiagnostics(document);
+
+        assert.deepStrictEqual(diagnostics, [
+            {
+                range: { start: { line: 1, character: 15 }, end: { line: 1, character: 27 } },
+                message:
+                    "Component has unused export property 'name'. If it is for external reference only, please consider using `export const name`",
+                severity: 2,
+                source: 'svelte',
+                code: 'unused-export-let',
+            },
+        ]);
+    });
 });

packages/language-server/test/plugins/svelte/testfiles/diagnostics-module.svelte

@@ -0,0 +1,3 @@
+<script context="module" lang="typescript">
+    export let name: string;
+</script>

packages/language-server/test/plugins/svelte/testfiles/diagnostics.svelte

@@ -0,0 +1,3 @@
+<script lang="typescript">
+    export let name: string;
+</script>