fix: put untyped plugin to first to avoid losing returnType. (#160)

Author: kricsleo

src/loader/babel.ts

@@ -16,9 +16,17 @@ const babelPluginUntyped: PluginItem = function (
   api: ConfigAPI,
   options: { experimentalFunctions?: boolean },
 ) {
+  const name = "untyped";
   api.cache.using(() => version);
 
   return <PluginObj>{
+    name,
+    manipulateOptions(opts: { plugins: Array<{ key: string }> }) {
+      // This `untyped` plugin must come before the `transform-typescript` plugin,
+      // otherwise the `returnType` annotations will be removed.
+      // So put it at the beginning.
+      opts.plugins!.sort((a) => (a.key === name ? -1 : 0));
+    },
     visitor: {
       VariableDeclaration(p) {
         const declaration = p.node.declarations[0];

test/fixtures/functions.ts

@@ -0,0 +1,3 @@
+export function main(a: number): string {
+  return a.toString();
+}

test/loader.test.ts

@@ -36,4 +36,36 @@ describe("loader", () => {
       }
     `);
   });
+
+  it("should load a schema with function return type annotations", async () => {
+    const schema = await loadSchema("./test/fixtures/functions.ts");
+    expect(schema).toMatchInlineSnapshot(`
+      {
+        "default": {},
+        "id": "#",
+        "properties": {
+          "main": {
+            "args": [
+              {
+                "items": {},
+                "name": "a",
+                "tsType": "number",
+                "type": "number",
+              },
+            ],
+            "description": "",
+            "id": "#main",
+            "returns": {
+              "tsType": "string",
+              "type": "string",
+            },
+            "tags": [],
+            "title": "",
+            "type": "function",
+          },
+        },
+        "type": "object",
+      }
+    `);
+  });
 });