feat(syntax): parse sectioned api blocks

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/syntax/test/api-block.test.ts

@@ -0,0 +1,98 @@
+import { expect, test } from "bun:test";
+import { parse } from "../src/index.ts";
+
+const page = (inner: string) => `page Repro {
+  client {
+${inner}
+  }
+
+  view { <main>x</main> }
+}
+`;
+
+test("parses a sectioned api block into request, response and error", () => {
+  const ast = parse(
+    page(`    api searchUsers POST /api/users {
+      request {
+        body {
+          name?: string
+          age?: number
+        }
+      }
+
+      response {
+        return data.users
+      }
+
+      error {
+        return []
+      }
+    }`),
+  );
+
+  const block = ast.dataApis[0]!;
+  expect(block.name).toBe("searchUsers");
+  expect(block.method).toBe("POST");
+  expect(block.path).toBe("/api/users");
+  expect(block.sections?.body).toEqual([
+    { name: "name", optional: true, type: "string" },
+    { name: "age", optional: true, type: "number" },
+  ]);
+  expect(block.sections?.response.trim()).toBe("return data.users");
+  expect(block.sections?.error.trim()).toBe("return []");
+});
+
+test("a bare body still parses as the legacy response body", () => {
+  const ast = parse(
+    page(`    api legacyUsers GET /api/users {
+      return users.length
+    }`),
+  );
+
+  const block = ast.dataApis[0]!;
+  expect(block.sections).toBeUndefined();
+  expect(block.body.trim()).toBe("return users.length");
+});
+
+test("GET parameters are parsed as required when not marked optional", () => {
+  const ast = parse(
+    page(`    api listUsers GET /api/users {
+      request {
+        parameters {
+          team: string
+        }
+      }
+
+      response {
+        return data.users
+      }
+    }`),
+  );
+
+  expect(ast.dataApis[0]!.sections?.parameters).toEqual([
+    { name: "team", optional: false, type: "string" },
+  ]);
+});
+
+test("request inside an ssr block is rejected with a message naming the restriction", () => {
+  const source = `page Repro {
+  ssr {
+    api ssrUsers GET /api/users {
+      request {
+        parameters {
+          team: string
+        }
+      }
+
+      response {
+        return data.users
+      }
+    }
+  }
+
+  view { <main>x</main> }
+}
+`;
+
+  expect(() => parse(source)).toThrow(/ssr[\s\S]*request/i);
+});