Catch errors when trying to unwrap responses

.changeset/catch-unwrap-error.md

@@ -0,0 +1,5 @@
+---
+"@remix-run/router": patch
+---
+
+Catch and bubble errors thrown when trying to unwrap responses from `loader`/`action` functions

packages/router/__tests__/navigation-test.ts

@@ -124,6 +124,75 @@ describe("navigations", () => {
       });
     });
 
+    it("handles errors when unwrapping Responses", async () => {
+      let t = setup({
+        routes: [
+          {
+            path: "/",
+            children: [
+              {
+                id: "foo",
+                path: "foo",
+                hasErrorBoundary: true,
+                loader: true,
+              },
+            ],
+          },
+        ],
+      });
+      let A = await t.navigate("/foo");
+      await A.loaders.foo.resolve(
+        // Invalid JSON
+        new Response('{"key":"value"}}}}}', {
+          status: 200,
+          headers: {
+            "Content-Type": "application/json",
+          },
+        })
+      );
+      expect(t.router.state.loaderData).toEqual({});
+      expect(t.router.state.errors).toMatchInlineSnapshot(`
+        {
+          "foo": [SyntaxError: Unexpected token } in JSON at position 15],
+        }
+      `);
+    });
+
+    it("bubbles errors when unwrapping Responses", async () => {
+      let t = setup({
+        routes: [
+          {
+            id: "root",
+            path: "/",
+            hasErrorBoundary: true,
+            children: [
+              {
+                id: "foo",
+                path: "foo",
+                loader: true,
+              },
+            ],
+          },
+        ],
+      });
+      let A = await t.navigate("/foo");
+      await A.loaders.foo.resolve(
+        // Invalid JSON
+        new Response('{"key":"value"}}}}}', {
+          status: 200,
+          headers: {
+            "Content-Type": "application/json",
+          },
+        })
+      );
+      expect(t.router.state.loaderData).toEqual({});
+      expect(t.router.state.errors).toMatchInlineSnapshot(`
+        {
+          "root": [SyntaxError: Unexpected token } in JSON at position 15],
+        }
+      `);
+    });
+
     it("does not fetch unchanging layout data", async () => {
       let t = initializeTest();
       let A = await t.navigate("/foo");

packages/router/router.ts

@@ -3991,13 +3991,18 @@ async function callLoaderOrAction(
     }
 
     let data: any;
-    let contentType = result.headers.get("Content-Type");
-    // Check between word boundaries instead of startsWith() due to the last
-    // paragraph of https://httpwg.org/specs/rfc9110.html#field.content-type
-    if (contentType && /\bapplication\/json\b/.test(contentType)) {
-      data = await result.json();
-    } else {
-      data = await result.text();
+
+    try {
+      let contentType = result.headers.get("Content-Type");
+      // Check between word boundaries instead of startsWith() due to the last
+      // paragraph of https://httpwg.org/specs/rfc9110.html#field.content-type
+      if (contentType && /\bapplication\/json\b/.test(contentType)) {
+        data = await result.json();
+      } else {
+        data = await result.text();
+      }
+    } catch (e) {
+      return { type: ResultType.error, error: e };
     }
 
     if (resultType === ResultType.error) {