Add copy page to core plugin (#418)

plugs/core/core.plug.yaml

@@ -47,6 +47,10 @@ functions:
     path: "./page.ts:deletePage"
     command:
       name: "Page: Delete"
+  copyPage:
+    path: "./page.ts:copyPage"
+    command:
+      name: "Page: Copy"
 
   # Attachments
   attachmentQueryProvider:

plugs/core/page.ts

@@ -93,6 +93,39 @@ export async function deletePage() {
   await space.deletePage(pageName);
 }
 
+export async function copyPage() {
+  const oldName = await editor.getCurrentPage();
+  const newName = await editor.prompt(`New page title:`, `${oldName} (copy)`);
+
+  if (!newName) {
+    return;
+  }
+
+  try {
+    // This throws an error if the page does not exist, which we expect to be the case
+    await space.getPageMeta(newName);
+    // So when we get to this point, we error out
+    throw new Error(
+        `Page ${newName} already exists, cannot rename to existing page.`,
+    );
+  } catch (e: any) {
+    if (e.message === "Not found") {
+      // Expected not found error, so we can continue
+    } else {
+      await editor.flashNotification(e.message, "error");
+      throw e;
+    }
+  }
+
+  const text = await editor.getText();
+
+  console.log("Writing new page to space");
+  await space.writePage(newName, text);
+
+  console.log("Navigating to new page");
+  await editor.navigate(newName);
+}
+
 export async function renamePage(cmdDef: any) {
   console.log("Got a target name", cmdDef.page);
   const oldName = await editor.getCurrentPage();