fix: Correctly paste contents parsed by JSON.parse() as text. (#5868)

* Fix #5867

* Add test.

* Add tests to clipboard.test.ts

Co-authored-by: Aakansha Doshi <aakansha1216@gmail.com>

src/clipboard.test.ts

@@ -0,0 +1,27 @@
+import { parseClipboard } from "./clipboard";
+
+describe("Test parseClipboard", () => {
+  it("should parse valid json correctly", async () => {
+    let text = "123";
+
+    let clipboardData = await parseClipboard({
+      //@ts-ignore
+      clipboardData: {
+        getData: () => text,
+      },
+    });
+
+    expect(clipboardData.text).toBe(text);
+
+    text = "[123]";
+
+    clipboardData = await parseClipboard({
+      //@ts-ignore
+      clipboardData: {
+        getData: () => text,
+      },
+    });
+
+    expect(clipboardData.text).toBe(text);
+  });
+});

src/clipboard.ts

@@ -156,15 +156,13 @@ export const parseClipboard = async (
         files: systemClipboardData.files,
       };
     }
-    return appClipboardData;
+  } catch (e) {}
-  } catch {
+  // system clipboard doesn't contain excalidraw elements → return plaintext
-    // system clipboard doesn't contain excalidraw elements → return plaintext
+  // unless we set a flag to prefer in-app clipboard because browser didn't
-    // unless we set a flag to prefer in-app clipboard because browser didn't
+  // support storing to system clipboard on copy
-    // support storing to system clipboard on copy
+  return PREFER_APP_CLIPBOARD && appClipboardData.elements
-    return PREFER_APP_CLIPBOARD && appClipboardData.elements
+    ? appClipboardData
-      ? appClipboardData
+    : { text: systemClipboard };
-      : { text: systemClipboard };
-  }
 };
 
 export const copyBlobToClipboardAsPng = async (blob: Blob | Promise<Blob>) => {