test(data-table): add unit tests

tests/DataTable/DataTableBatchSelectionToolbar.test.svelte

@@ -0,0 +1,60 @@
+<script lang="ts">
+  import {
+    DataTable,
+    Toolbar,
+    ToolbarContent,
+    ToolbarBatchActions,
+    Button,
+  } from "carbon-components-svelte";
+
+  const headers = [
+    { key: "name", value: "Name" },
+    { key: "port", value: "Port" },
+    { key: "rule", value: "Rule" },
+  ] as const;
+
+  const rows = [
+    { id: "a", name: "Load Balancer 3", port: 3000, rule: "Round robin" },
+    { id: "b", name: "Load Balancer 1", port: 443, rule: "Round robin" },
+    { id: "c", name: "Load Balancer 2", port: 80, rule: "DNS delegation" },
+    { id: "d", name: "Load Balancer 6", port: 3000, rule: "Round robin" },
+    { id: "e", name: "Load Balancer 4", port: 443, rule: "Round robin" },
+    { id: "f", name: "Load Balancer 5", port: 80, rule: "DNS delegation" },
+  ];
+
+  export let selectedRowIds: string[] = [];
+  export let active: boolean | undefined = undefined;
+  export let controlled = false;
+</script>
+
+<DataTable batchSelection {headers} {rows} {selectedRowIds}>
+  <Toolbar>
+    <ToolbarBatchActions
+      {active}
+      on:cancel={() => {
+        if (!controlled) {
+          selectedRowIds = [];
+        }
+      }}
+    >
+      <Button
+        kind="danger"
+        on:click={() => {
+          console.log("delete", selectedRowIds);
+        }}
+      >
+        Delete
+      </Button>
+      <Button
+        on:click={() => {
+          console.log("restart", selectedRowIds);
+        }}
+      >
+        Restart
+      </Button>
+    </ToolbarBatchActions>
+    <ToolbarContent>
+      <Button>Create balancer</Button>
+    </ToolbarContent>
+  </Toolbar>
+</DataTable>