From ead67b6a540ed3350c53686a4ef57388222c5185 Mon Sep 17 00:00:00 2001
From: Henry Dineen <hdineen@hubspot.com>
Date: Wed, 12 Jun 2024 15:22:48 -0400
Subject: [PATCH] fix: TSTypeAnnotation printer when parent is a TSFunction
 type

---
 lib/printer.ts  | 12 ++++++++++--
 test/printer.ts | 28 ++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/lib/printer.ts b/lib/printer.ts
index e3f834f0..d3d0aab4 100644
--- a/lib/printer.ts
+++ b/lib/printer.ts
@@ -2307,8 +2307,16 @@ function genericPrintNoParens(path: any, options: any, print: any) {
     case "TSNonNullExpression":
       return concat([path.call(print, "expression"), "!"]);
 
-    case "TSTypeAnnotation":
-      return concat([": ", path.call(print, "typeAnnotation")]);
+    case "TSTypeAnnotation": {
+      const isFunctionType = namedTypes.TSFunctionType.check(
+        path.getParentNode(0),
+      );
+
+      return concat([
+        isFunctionType ? "=> " : ": ",
+        path.call(print, "typeAnnotation"),
+      ]);
+    }
 
     case "TSIndexSignature":
       return concat([
diff --git a/test/printer.ts b/test/printer.ts
index e25a961d..313408c0 100644
--- a/test/printer.ts
+++ b/test/printer.ts
@@ -2600,4 +2600,32 @@ describe("printer", function () {
       ),
     );
   });
+
+  it("should reprint TSTypeAnnotation correctly", function () {
+    const code = "type Foo = () => Bar;";
+
+    const ast = parse(code, {
+      parser: tsParser,
+    });
+
+    recast.visit(ast, {
+      visitTSTypeReference(path) {
+        if (
+          path.node.typeName.type === "Identifier" &&
+          path.node.typeName.name === "Bar" &&
+          path.parentPath.node.type === "TSTypeAnnotation"
+        ) {
+          path.replace(
+            b.tsQualifiedName(b.identifier("Bar"), b.identifier("Baz")),
+          );
+        }
+
+        this.traverse(path);
+      },
+    });
+
+    const pretty = new Printer().print(ast).code;
+
+    assert.strictEqual(pretty, "type Foo = () => Bar.Baz;");
+  });
 });