(fix) ignore error about transition third argument (#2139)

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

@@ -41,7 +41,8 @@ export enum DiagnosticCode {
     MISSING_PROPS = 2739, // "Type '...' is missing the following properties from type '..': ..."
     MISSING_PROP = 2741, // "Property '..' is missing in type '..' but required in type '..'."
     NO_OVERLOAD_MATCHES_CALL = 2769, // "No overload matches this call"
-    CANNOT_FIND_NAME = 2304 // "Cannot find name 'xxx'"
+    CANNOT_FIND_NAME = 2304, // "Cannot find name 'xxx'"
+    EXPECTED_N_ARGUMENTS = 2554 // Expected {0} arguments, but got {1}.
 }
 
 export class DiagnosticsProviderImpl implements DiagnosticsProvider {
@@ -117,7 +118,11 @@ export class DiagnosticsProviderImpl implements DiagnosticsProvider {
         }
         diagnostics.push(...additionalStoreDiagnostics);
 
-        diagnostics = diagnostics.filter(notGenerated).filter(not(isUnusedReactiveStatementLabel));
+        diagnostics = diagnostics
+            .filter(notGenerated)
+            .filter(not(isUnusedReactiveStatementLabel))
+            .filter((diagnostics) => !expectedTransitionThirdArgument(diagnostics, tsDoc, lang));
+
         diagnostics = resolveNoopsInReactiveStatements(lang, diagnostics);
 
         return diagnostics
@@ -499,3 +504,35 @@ function movePropsErrorRangeBackIfNecessary(
         });
     }
 }
+
+function expectedTransitionThirdArgument(
+    diagnostic: ts.Diagnostic,
+    tsDoc: SvelteDocumentSnapshot,
+    lang: ts.LanguageService
+) {
+    if (
+        diagnostic.code !== DiagnosticCode.EXPECTED_N_ARGUMENTS ||
+        !diagnostic.start ||
+        !tsDoc.getText(0, diagnostic.start).endsWith('__sveltets_2_ensureTransition(')
+    ) {
+        return false;
+    }
+
+    const node = findDiagnosticNode(diagnostic);
+    if (!node) {
+        return false;
+    }
+
+    const callExpression = findNodeAtSpan(
+        node,
+        { start: node.getStart(), length: node.getWidth() },
+        ts.isCallExpression
+    );
+    const signature =
+        callExpression && lang.getProgram()?.getTypeChecker().getResolvedSignature(callExpression);
+
+    return (
+        signature?.parameters.filter((parameter) => !(parameter.flags & ts.SymbolFlags.Optional))
+            .length === 3
+    );
+}

packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/transition-options/expectedv2.json

@@ -0,0 +1 @@
+[]

packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/transition-options/input.svelte

@@ -0,0 +1,11 @@
+<script lang="ts">
+    function myTransition(
+      _node: HTMLElement,
+      _params: { delay: number },
+      _context: { direction: 'in' | 'out' | 'both' }
+    ) {
+      return {};
+    }
+</script>
+
+<div in:myTransition={{ delay: 100 }} />