Do not silence runtime MDX errors (#7089)

* test: add fixture

* chore: remove unneeded files in fixture

* test: update test mdx filfe

* test: add test case

* mark component as mdx

* add error builder utility

* throw error when it comes from an MDX component

* chore: update lock file

* Add comment to refactor later

* apply review

* add missing comma

1 files changed, 40 insertions, 0 deletions

diff --git a/packages/integrations/mdx/test/invalid-mdx-component.test.js b/packages/integrations/mdx/test/invalid-mdx-component.test.js
new file mode 100644
index 000000000..a07401c60
--- /dev/null
+++ b/packages/integrations/mdx/test/invalid-mdx-component.test.js
@@ -0,0 +1,40 @@
+import { expect } from "chai";
+import { loadFixture } from "../../../astro/test/test-utils.js";
+import mdx from "../dist/index.js";
+
+const FIXTURE_ROOT = new URL(
+  "./fixtures/invalid-mdx-component/",
+  import.meta.url,
+);
+
+describe("MDX component with runtime error", () => {
+  let fixture;
+
+  before(async () => {
+    fixture = await loadFixture({
+      root: FIXTURE_ROOT,
+      integrations: [mdx()],
+    });
+  });
+
+  describe("build", () => {
+    /** @type {Error | null} */
+    let error;
+
+    before(async () => {
+      error = null;
+      try {
+        await fixture.build();
+      } catch (e) {
+        error = e;
+      }
+    });
+
+    it("Throws the right error", async () => {
+      expect(error).to.exist;
+      expect(error?.hint).to.match(
+        /This issue often occurs when your MDX component encounters runtime errors/,
+      );
+    });
+  });
+});