Fix hover text for ambient modules to display "module" instead of "namespace" (#2668)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: DanielRosenwasser <972891+DanielRosenwasser@users.noreply.github.com>

Author: Copilot

internal/fourslash/tests/quickInfoAmbientModule_test.go

@@ -0,0 +1,19 @@
+package fourslash_test
+
+import (
+	"testing"
+
+	"github.com/microsoft/typescript-go/internal/fourslash"
+	"github.com/microsoft/typescript-go/internal/testutil"
+)
+
+func TestQuickInfoAmbientModule(t *testing.T) {
+	t.Parallel()
+
+	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
+	const content = `declare module "*.css"/*1*/;`
+
+	f, done := fourslash.NewFourslash(t, nil /*capabilities*/, content)
+	defer done()
+	f.VerifyQuickInfoAt(t, "1", `module "*.css"`, "")
+}

internal/ls/hover.go

@@ -365,7 +365,8 @@ func getQuickInfoAndDeclarationAtLocation(c *checker.Checker, symbol *ast.Symbol
 		}
 		if flags&ast.SymbolFlagsModule != 0 {
 			writeNewLine()
-			b.WriteString(core.IfElse(symbol.ValueDeclaration != nil && ast.IsSourceFile(symbol.ValueDeclaration), "module ", "namespace "))
+			isModule := symbol.ValueDeclaration != nil && (ast.IsSourceFile(symbol.ValueDeclaration) || ast.IsAmbientModule(symbol.ValueDeclaration))
+			b.WriteString(core.IfElse(isModule, "module ", "namespace "))
 			b.WriteString(c.SymbolToStringEx(symbol, container, ast.SymbolFlagsNone, symbolFormatFlags))
 			setDeclaration(core.Find(symbol.Declarations, ast.IsModuleDeclaration))
 		}