feat: list_bases returns registered table storage prefixes

Return the additional storage bases for the current table snapshot
on native, memory, namespace, and Cloud clients.

nodejs/__test__/remote.test.ts

@@ -1028,11 +1028,30 @@ describe("remote connection jobs surface", () => {
           });
           return;
         }
+        if (path.endsWith("/bases/list/")) {
+          res.writeHead(200, { "Content-Type": "application/json" }).end(
+            JSON.stringify({
+              bases: [
+                {
+                  path: "s3://bucket/media/",
+                  isDatasetRoot: false,
+                },
+              ],
+            }),
+          );
+          return;
+        }
         res.writeHead(404).end();
       },
       async (db) => {
         const table = await db.openTable("photos");
         await table.addBases({ path: "s3://bucket/media/" });
+        expect(await table.listBases()).toEqual([
+          {
+            path: "s3://bucket/media/",
+            isDatasetRoot: false,
+          },
+        ]);
       },
     );
     expect(postedBodies).toEqual([
@@ -1046,4 +1065,47 @@ describe("remote connection jobs surface", () => {
       },
     ]);
   });
+
+  it("listBases returns a named dataset-root base", async () => {
+    await withMockDatabase(
+      (req, res) => {
+        const path = req.url ?? "";
+        if (path.endsWith("/describe/")) {
+          res.writeHead(200, { "Content-Type": "application/json" }).end(
+            JSON.stringify({
+              name: "photos",
+              version: 1,
+              schema: { fields: [] },
+            }),
+          );
+          return;
+        }
+        if (path.endsWith("/bases/list/")) {
+          res.writeHead(200, { "Content-Type": "application/json" }).end(
+            JSON.stringify({
+              bases: [
+                {
+                  path: "s3://bucket/archive/",
+                  name: "archive",
+                  isDatasetRoot: true,
+                },
+              ],
+            }),
+          );
+          return;
+        }
+        res.writeHead(404).end();
+      },
+      async (db) => {
+        const table = await db.openTable("photos");
+        expect(await table.listBases()).toEqual([
+          {
+            path: "s3://bucket/archive/",
+            name: "archive",
+            isDatasetRoot: true,
+          },
+        ]);
+      },
+    );
+  });
 });

nodejs/__test__/table.test.ts

@@ -3413,7 +3413,7 @@ describe("table bases", () => {
   });
   afterEach(() => tmpDir.removeCallback());
 
-  it("addBases accepts a file uri", async () => {
+  it("listBases reflects added bases", async () => {
     const conn = await connect(tmpDir.name);
     const table = await conn.createEmptyTable(
       "photos",
@@ -3421,6 +3421,12 @@ describe("table bases", () => {
     );
     const media = path.join(tmpDir.name, "media");
     fs.mkdirSync(media);
-    await table.addBases(pathToFileURL(media).toString());
+    const location = pathToFileURL(media).toString();
+
+    expect(await table.listBases()).toEqual([]);
+    await table.addBases(location);
+    expect(await table.listBases()).toEqual([
+      { path: location, isDatasetRoot: false },
+    ]);
   });
 });

nodejs/lancedb/table.ts

@@ -591,6 +591,9 @@ export abstract class Table {
     bases: string | TableBase | Array<string | TableBase>,
   ): Promise<void>;
 
+  /** Return the additional storage bases for the current table snapshot. */
+  abstract listBases(): Promise<TableBase[]>;
+
   /**
    * Fill the rows of a computed column that hold no value yet.
    *
@@ -1230,6 +1233,10 @@ export class LocalTable extends Table {
     await this.inner.addBases(normalizeBases(bases));
   }
 
+  async listBases(): Promise<TableBase[]> {
+    return await this.inner.listBases();
+  }
+
   async refreshColumn(column: string): Promise<RefreshColumnResult> {
     return await this.inner.refreshColumn(column);
   }

nodejs/src/table.rs

@@ -459,6 +459,18 @@ impl Table {
             .default_error()
     }
 
+    #[napi(catch_unwind)]
+    pub async fn list_bases(&self) -> napi::Result<Vec<TableBase>> {
+        Ok(self
+            .inner_ref()?
+            .list_bases()
+            .await
+            .default_error()?
+            .into_iter()
+            .map(TableBase::from)
+            .collect())
+    }
+
     #[napi(catch_unwind)]
     pub async fn drop_columns(&self, columns: Vec<String>) -> napi::Result<DropColumnsResult> {
         let col_refs = columns.iter().map(String::as_str).collect::<Vec<_>>();
@@ -725,6 +737,16 @@ pub struct TableBase {
     pub is_dataset_root: bool,
 }
 
+impl From<LanceTableBase> for TableBase {
+    fn from(base: LanceTableBase) -> Self {
+        Self {
+            path: base.path,
+            name: base.name,
+            is_dataset_root: base.is_dataset_root,
+        }
+    }
+}
+
 #[napi(object)]
 /// A description of an index currently configured on a column
 pub struct IndexConfig {