Set UseAliasDefinedOutsideCurrentScope in hover (#1516)

Author: jakebailey

internal/fourslash/tests/hoverAliasInImportedFile_test.go

@@ -0,0 +1,35 @@
+package fourslash_test
+
+import (
+	"testing"
+
+	"github.com/microsoft/typescript-go/internal/fourslash"
+	"github.com/microsoft/typescript-go/internal/testutil"
+)
+
+func TestHoverAliasInImportedFile(t *testing.T) {
+	t.Parallel()
+	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
+	const content = `
+// @filename: other2.ts
+export type SomeAliasType<T> = { value: T };
+
+// @filename: other.ts
+import { SomeAliasType } from './other2';
+
+declare function isSomeAliasType(x: any): x is SomeAliasType<any>;
+
+export { isSomeAliasType };
+
+// @filename: main.ts
+import { isSomeAliasType } from './other';
+
+export function processValue(value: any) {
+  if (/*1*/isSomeAliasType(value)) {
+    console.log("ok");
+  }
+}
+`
+	f := fourslash.NewFourslash(t, nil /*capabilities*/, content)
+	f.VerifyQuickInfoAt(t, "1", "(alias) function isSomeAliasType(x: any): x is SomeAliasType<any>", "")
+}

internal/ls/hover.go

@@ -15,7 +15,7 @@ import (
 
 const (
 	symbolFormatFlags = checker.SymbolFormatFlagsWriteTypeParametersOrArguments | checker.SymbolFormatFlagsUseOnlyExternalAliasing | checker.SymbolFormatFlagsAllowAnyNodeKind | checker.SymbolFormatFlagsUseAliasDefinedOutsideCurrentScope
-	typeFormatFlags   = checker.TypeFormatFlagsNone
+	typeFormatFlags   = checker.TypeFormatFlagsUseAliasDefinedOutsideCurrentScope
 )
 
 func (l *LanguageService) ProvideHover(ctx context.Context, documentURI lsproto.DocumentUri, position lsproto.Position) (lsproto.HoverResponse, error) {