Merge pull request #4 from ccri/empty-table

Fix exception for empty Table
apache · Jan 25, 2018 · 272d293 · 272d293
2 parents 8ddce0a + 7bc7363
commit 272d293
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/js/src/table.ts b/js/src/table.ts
@@ -101,7 +101,9 @@ export class Table implements DataFrame {
         }
         this.schema = schema;
         this.batches = batches;
-        this.batchesUnion = batches.reduce((union, batch) => union.concat(batch));
+        this.batchesUnion = batches.length == 0 ?
+            new RecordBatch(schema, 0, []) :
+            batches.reduce((union, batch) => union.concat(batch));
         this.length = this.batchesUnion.length;
         this.numCols = this.batchesUnion.numCols;
     }

diff --git a/js/test/unit/table-tests.ts b/js/test/unit/table-tests.ts
@@ -24,6 +24,10 @@ const {
 } = Arrow;
 
 describe(`Table`, () => {
+    test(`can create an empty table`, () => {
+        expect(Table.empty().length).toEqual(0)
+    });
+
     describe(`single record batch`, () => {
         const table = Table.from({
           'schema': {