test: add missing unit test for diff() with series along axis 0

Author: NeonSpork

src/danfojs-browser/tests/core/frame.test.js

@@ -1085,6 +1085,12 @@ describe("DataFrame", function () {
       const df = new dfd.DataFrame(data);
       assert.deepEqual((df.diff(sf)).values, [ [ -1, 0, 3 ], [ 9, 8, 9 ], [ 0, 0, 2 ] ]);
     });
+    it("Return difference of a DataFrame with a Series along axis 0", function () {
+      const data = [ [ 0, 2, 4 ], [ 10, 10, 10 ], [ 1, 2, 3 ] ];
+      const sf = new dfd.Series([ 1, 2, 1 ]);
+      const df = new dfd.DataFrame(data);
+      assert.deepEqual((df.diff(sf, { axis: 0 })).values, [ [ -1, 1, 3 ], [ 8, 8, 8 ], [ 0, 1, 2 ] ]);
+    });
     it("Return difference of a DataFrame with along axis 0 (column-wise), previous column", function () {
       const data = [ [ 0, 2, 4 ], [ 10, 10, 10 ], [ 1, 2, 3 ] ];
       const df = new dfd.DataFrame(data);

src/danfojs-node/test/core/frame.test.ts

@@ -1014,6 +1014,12 @@ describe("DataFrame", function () {
             const df = new DataFrame(data);
             assert.deepEqual((df.diff(sf) as DataFrame).values, [[-1, 0, 3], [9, 8, 9], [0, 0, 2]]);
         });
+        it("Return difference of a DataFrame with a Series along axis 0", function () {
+            const data = [[0, 2, 4], [10, 10, 10], [1, 2, 3]];
+            const sf = new Series([1, 2, 1]);
+            const df = new DataFrame(data);
+            assert.deepEqual((df.diff(sf, {axis: 0}) as DataFrame).values, [[-1, 1, 3], [8, 8, 8], [0, 1, 2]]);
+        });
         it("Return difference of a DataFrame with along axis 0 (column-wise), previous column", function () {
             const data = [[0, 2, 4], [10, 10, 10], [1, 2, 3]];
             const df = new DataFrame(data);