diff --git a/src/hooks/useEcharts.ts b/src/hooks/useEcharts.ts
index 7e661d9c..052b751e 100644
--- a/src/hooks/useEcharts.ts
+++ b/src/hooks/useEcharts.ts
@@ -14,12 +14,18 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import { BarSeriesOption, LineSeriesOption } from "echarts/charts";
+import {
+  BarSeriesOption,
+  LineSeriesOption,
+  HeatmapSeriesOption,
+  PieSeriesOption,
+} from "echarts/charts";
 import {
   TitleComponentOption,
   TooltipComponentOption,
   GridComponentOption,
   DatasetComponentOption,
+  LegendComponentOption,
 } from "echarts/components";
 import type { Ref } from "vue";
 import { useTimeoutFn } from "./useTimeout";
@@ -37,6 +43,9 @@ export type ECOption = echarts.ComposeOption<
   | TooltipComponentOption
   | GridComponentOption
   | DatasetComponentOption
+  | LegendComponentOption
+  | HeatmapSeriesOption
+  | PieSeriesOption
 >;
 
 export function useECharts(
@@ -46,7 +55,7 @@ export function useECharts(
   const getDarkMode = computed(() => {
     return theme === "default" ? "light" : theme;
   });
-  let chartInstance: echarts.ECharts | null = null;
+  let chartInstance: Nullable<echarts.ECharts> = null;
   let resizeFn: Fn = resize;
   const cacheOptions = ref({}) as Ref<ECOption>;
   let removeResizeFn: Fn = () => ({});
@@ -128,7 +137,7 @@ export function useECharts(
     chartInstance = null;
   });
 
-  function getInstance(): echarts.ECharts | null {
+  function getInstance(): Nullable<echarts.ECharts> {
     if (!chartInstance) {
       initCharts(getDarkMode.value as "default");
     }
diff --git a/src/utils/is.ts b/src/utils/is.ts
index e55b1925..edf4ef36 100644
--- a/src/utils/is.ts
+++ b/src/utils/is.ts
@@ -32,22 +32,6 @@ export function isObject(val: unknown): val is Record<any, any> {
   return val !== null && is(val, "Object");
 }
 
-export function isEmpty<T = unknown>(val: any): val is T {
-  if (isArray(val) || isString(val)) {
-    return val.length === 0;
-  }
-
-  if (val instanceof Map || val instanceof Set) {
-    return val.size === 0;
-  }
-
-  if (isObject(val)) {
-    return Object.keys(val).length === 0;
-  }
-
-  return false;
-}
-
 export function isDate(val: unknown): val is Date {
   return is(val, "Date");
 }
@@ -81,7 +65,7 @@ export function isString(val: unknown): val is string {
   return is(val, "String");
 }
 
-export function isFunction(val: unknown): boolean {
+export function isFunction(val: unknown): val is () => unknown {
   return typeof val === "function";
 }
 
@@ -93,8 +77,8 @@ export function isRegExp(val: unknown): val is RegExp {
   return is(val, "RegExp");
 }
 
-export function isArray(val: any): boolean {
-  return val && Array.isArray(val);
+export function isArray(val: unknown): boolean {
+  return Array.isArray(val);
 }
 
 export function isWindow(val: unknown): val is Window {