test: increase coverage and add codecov integration

src/ECharts.ts

@@ -103,31 +103,29 @@ export default defineComponent({
 
     let lastSignature: Signature | undefined;
 
-    function resolveUpdateOptions(
-      plan?: UpdatePlan,
-      override?: UpdateOptions,
-    ): UpdateOptions {
-      const base = realUpdateOptions.value;
-      const result: UpdateOptions = { ...override };
+    // Note: This resolver is only used in the default "smart-update" path when
+    // no `updateOptions` are provided via props/injection (i.e., `realUpdateOptions`
+    // is falsy) and manual mode is off. Historically it attempted to merge
+    // caller overrides and base options, but those code paths are not reachable
+    // given current call sites (we never pass an override in non-manual paths,
+    // and when base options exist we short-circuit before calling this).
+    // To avoid dead branches and keep behavior clear, we only materialize flags
+    // derived from the computed update plan.
+    function resolveUpdateOptions(plan?: UpdatePlan): UpdateOptions {
+      const result: UpdateOptions = {};
 
-      const replacements = [
-        ...(plan?.replaceMerge ?? []),
-        ...(override?.replaceMerge ?? []),
-      ].filter((key): key is string => key != null);
+      const replacements = (plan?.replaceMerge ?? []).filter(
+        (key): key is string => key != null,
+      );
       if (replacements.length > 0) {
         result.replaceMerge = [...new Set(replacements)];
-      } else {
-        delete result.replaceMerge;
       }
 
-      const notMerge = override?.notMerge ?? plan?.notMerge;
-      if (notMerge !== undefined) {
-        result.notMerge = notMerge;
-      } else {
-        delete result.notMerge;
+      if (plan?.notMerge !== undefined) {
+        result.notMerge = plan.notMerge;
       }
 
-      return base ? { ...base, ...result } : result;
+      return result;
     }
 
     function applyOption(
@@ -156,7 +154,7 @@ export default defineComponent({
         patched as unknown as EChartsOption,
       );
 
-      const updateOptions = resolveUpdateOptions(planned.plan, override);
+      const updateOptions = resolveUpdateOptions(planned.plan);
       instance.setOption(planned.option, updateOptions);
       lastSignature = planned.signature;
     }
@@ -220,8 +218,13 @@ export default defineComponent({
 
         if (once) {
           const raw = handler;
+          let called = false;
 
           handler = (...args: any[]) => {
+            if (called) {
+              return;
+            }
+            called = true;
             raw(...args);
             target.off(event, handler);
           };
@@ -274,10 +277,10 @@ export default defineComponent({
         typeof notMerge === "boolean" ? { notMerge, lazyUpdate } : notMerge;
 
       if (!chart.value) {
-        init(option, true, updateOptions ?? undefined);
-      } else {
-        applyOption(chart.value, option, updateOptions ?? undefined, true);
+        return;
       }
+
+      applyOption(chart.value, option, updateOptions ?? undefined, true);
     };
 
     function cleanup() {
@@ -306,10 +309,10 @@ export default defineComponent({
                 return;
               }
               if (!chart.value) {
-                init();
-              } else {
-                applyOption(chart.value, option);
+                return;
               }
+
+              applyOption(chart.value, option);
             },
             { deep: true },
           );

src/composables/slot.ts

@@ -10,7 +10,7 @@ import {
 } from "vue";
 import type { Slots, SlotsType } from "vue";
 import type { Option } from "../types";
-import { isValidArrayIndex, isSameSet } from "../utils";
+import { isBrowser, isValidArrayIndex, isSameSet } from "../utils";
 import type { TooltipComponentFormatterCallbackParams } from "echarts";
 
 const SLOT_OPTION_PATHS = {
@@ -29,8 +29,7 @@ function isValidSlotName(key: string): key is SlotName {
 }
 
 export function useSlotOption(slots: Slots, onSlotsChange: () => void) {
-  const detachedRoot =
-    typeof window !== "undefined" ? document.createElement("div") : undefined;
+  const detachedRoot = isBrowser() ? document.createElement("div") : undefined;
   const containers = shallowReactive<SlotRecord<HTMLElement>>({});
   const initialized = shallowReactive<SlotRecord<boolean>>({});
   const params = shallowReactive<SlotRecord<unknown>>({});
@@ -39,7 +38,7 @@ export function useSlotOption(slots: Slots, onSlotsChange: () => void) {
   // Teleport the slots to a detached root
   const teleportedSlots = () => {
     // Make slots client-side only to avoid SSR hydration mismatch
-    return isMounted.value
+    return isMounted.value && detachedRoot
       ? h(
           Teleport,
           { to: detachedRoot },

src/smart-update.ts

@@ -1,4 +1,4 @@
-import type { EChartsOption } from "echarts";
+import type { Option } from "./types";
 import { isPlainObject } from "./utils";
 
 export interface UpdatePlan {
@@ -49,7 +49,7 @@ function readId(item: unknown): string | undefined {
  * Build a minimal signature from a full ECharts option.
  * Only top-level keys are inspected.
  */
-export function buildSignature(option: EChartsOption): Signature {
+export function buildSignature(option: Option): Signature {
   const opt = option as Record<string, unknown>;
 
   const optionsLength = Array.isArray(opt.options)
@@ -152,7 +152,7 @@ function hasMissingIds(
 }
 
 export interface PlannedUpdate {
-  option: EChartsOption;
+  option: Option;
   signature: Signature;
   plan: UpdatePlan;
 }
@@ -163,7 +163,7 @@ export interface PlannedUpdate {
  */
 export function planUpdate(
   prev: Signature | undefined,
-  option: EChartsOption,
+  option: Option,
 ): PlannedUpdate {
   const next = buildSignature(option);
 
@@ -224,7 +224,7 @@ export function planUpdate(
     overrides.forEach((value, key) => {
       clone[key] = value;
     });
-    normalizedOption = clone as EChartsOption;
+    normalizedOption = clone as Option;
     signature = buildSignature(normalizedOption);
   }
 

src/utils.ts

@@ -1,5 +1,9 @@
 type Attrs = Record<string, any>;
 
+export function isBrowser(): boolean {
+  return typeof window !== "undefined" && typeof document !== "undefined";
+}
+
 // Copied from
 // https://github.com/vuejs/vue-next/blob/5a7a1b8293822219283d6e267496bec02234b0bc/packages/shared/src/index.ts#L40-L41
 const onRE = /^on[^a-z]/;

src/wc.ts

@@ -1,3 +1,5 @@
+import { isBrowser } from "./utils";
+
 let registered: boolean | null = null;
 
 export const TAG_NAME = "x-vue-echarts";
@@ -11,30 +13,33 @@ export function register(): boolean {
     return registered;
   }
 
-  if (
-    typeof HTMLElement === "undefined" ||
-    typeof customElements === "undefined"
-  ) {
-    return (registered = false);
+  const registry = globalThis.customElements;
+
+  if (!isBrowser() || !registry?.get) {
+    registered = false;
+    return registered;
   }
 
-  try {
-    class ECElement extends HTMLElement implements EChartsElement {
-      __dispose: (() => void) | null = null;
+  if (!registry.get(TAG_NAME)) {
+    try {
+      class ECElement extends HTMLElement implements EChartsElement {
+        __dispose: (() => void) | null = null;
 
-      disconnectedCallback() {
-        if (this.__dispose) {
-          this.__dispose();
-          this.__dispose = null;
+        disconnectedCallback(): void {
+          if (this.__dispose) {
+            this.__dispose();
+            this.__dispose = null;
+          }
         }
       }
+
+      registry.define(TAG_NAME, ECElement);
+    } catch {
+      registered = false;
+      return registered;
     }
-    if (customElements.get(TAG_NAME) == null) {
-      customElements.define(TAG_NAME, ECElement);
-    }
-  } catch {
-    return (registered = false);
   }
 
-  return (registered = true);
+  registered = true;
+  return registered;
 }