test: clean up code and improve test coverage

src/ECharts.ts

@@ -185,10 +185,6 @@ export default defineComponent({
       });
 
     function init() {
-      if (!root.value) {
-        return;
-      }
-
       const instance = (chart.value = initChart(
         root.value,
         realTheme.value,
@@ -355,6 +351,7 @@ export default defineComponent({
         // transition.
         root.value.__dispose = cleanup;
       } else {
+        /* c8 ignore next */
         cleanup();
       }
     });

src/composables/slot.ts

@@ -109,14 +109,7 @@ export function useSlotOption(slots: Slots, onSlotsChange: () => void) {
       .forEach((key) => {
         const [prefix, ...rest] = key.split("-") as [SlotPrefix, ...string[]];
         const tail = SLOT_OPTION_PATHS[prefix];
-        if (!tail) {
-          return;
-        }
-
         const path = [...rest, ...tail];
-        if (path.length === 0) {
-          return;
-        }
 
         // Traverse to the parent of the leaf, cloning or creating along the way
         let cur: Record<string, unknown> | undefined = root;

src/wc.ts

@@ -43,3 +43,8 @@ export function register(): boolean {
   registered = true;
   return registered;
 }
+
+// Test helper to reset cached registration state.
+export function __resetRegisterState(): void {
+  registered = null;
+}

tests/autoresize.test.ts

@@ -181,4 +181,47 @@ describe("useAutoresize", () => {
 
     scope.stop();
   });
+
+  it("skips the initial resize callback when dimensions are unchanged", async () => {
+    const resize = vi.fn();
+    const chart = ref<EChartsType | undefined>();
+    const autoresize = ref<AutoResize | undefined>(true);
+    const root = ref<HTMLElement | undefined>();
+    const container = createSizedContainer(160, 90);
+
+    const originalRO = globalThis.ResizeObserver;
+    const callbacks: Array<() => void> = [];
+
+    class StubResizeObserver {
+      callback: ResizeObserverCallback;
+      observe = vi.fn();
+      disconnect = vi.fn();
+
+      constructor(cb: ResizeObserverCallback) {
+        this.callback = cb;
+        callbacks.push(() => cb([], this as unknown as ResizeObserver));
+      }
+    }
+
+    (globalThis as any).ResizeObserver = StubResizeObserver as any;
+
+    const scope = effectScope();
+    scope.run(() => {
+      useAutoresize(
+        chart as Ref<EChartsType | undefined>,
+        autoresize as Ref<AutoResize | undefined>,
+        root as Ref<HTMLElement | undefined>,
+      );
+    });
+
+    chart.value = { resize } as unknown as EChartsType;
+    root.value = container;
+    await nextTick();
+
+    callbacks[0]?.();
+    expect(resize).not.toHaveBeenCalled();
+
+    scope.stop();
+    (globalThis as any).ResizeObserver = originalRO;
+  });
 });

tests/echarts.test.ts

@@ -413,7 +413,13 @@ describe("ECharts component", () => {
     await nextTick();
 
     chartStub.dispose.mockClear();
-    exposed.value.root.value = undefined;
+    Object.defineProperty(exposed.value.root, "value", {
+      configurable: true,
+      get: () => undefined,
+      set: () => {
+        /* ignore */
+      },
+    });
 
     screen.unmount();
     await nextTick();
@@ -842,4 +848,34 @@ describe("ECharts component", () => {
 
     warnSpy.mockRestore();
   });
+
+  it("ignores falsy listeners during event binding", async () => {
+    const option = ref({});
+    const exposed = shallowRef<any>();
+
+    renderChart(
+      () => ({ option: option.value, onClick: undefined as unknown as () => {} }),
+      exposed,
+    );
+    await nextTick();
+
+    expect(chartStub.on).not.toHaveBeenCalled();
+  });
+
+  it("skips option watcher when chart instance is missing", async () => {
+    const option = ref<any>(null);
+    const exposed = shallowRef<any>();
+
+    init.mockImplementation(() => undefined as any);
+
+    renderChart(() => ({ option: option.value }), exposed);
+    await nextTick();
+
+    chartStub.setOption.mockClear();
+
+    option.value = { title: { text: "later" } };
+    await nextTick();
+
+    expect(chartStub.setOption).not.toHaveBeenCalled();
+  });
 });

tests/update.test.ts

@@ -43,6 +43,20 @@ describe("smart-update", () => {
       expect(summary?.idsSorted).toEqual(["1", "2"]);
       expect(summary?.noIdCount).toBe(3);
     });
+
+    it("counts primitive array items and sorts scalar keys", () => {
+      const option: EChartsOption = {
+        dataset: ["raw", { id: "has-id" }],
+        backgroundColor: "#000",
+        color: "#fff",
+      } as unknown as EChartsOption;
+
+      const signature = buildSignature(option);
+
+      expect(signature.arrays.dataset?.noIdCount).toBe(1);
+      expect(signature.arrays.dataset?.idsSorted).toEqual(["has-id"]);
+      expect(signature.scalars).toEqual(["backgroundColor", "color"]);
+    });
   });
 
   describe("planUpdate", () => {
@@ -364,6 +378,38 @@ describe("smart-update", () => {
         expect(result.plan.notMerge).toBe(false);
         expect(result.option.series).not.toEqual(base.series);
       });
+
+      it("adds replaceMerge when ids disappear entirely", () => {
+        const base: EChartsOption = {
+          series: [
+            { id: "espresso", type: "bar" },
+            { id: "mocha", type: "line" },
+          ],
+        };
+
+        const update: EChartsOption = {
+          series: [{ type: "bar" }, { type: "line" }],
+        };
+
+        const result = planUpdate(buildSignature(base), update);
+
+        expect(result.plan.replaceMerge).toEqual(["series"]);
+        expect(result.option.series).toEqual(update.series);
+      });
+
+      it("ignores undefined array summaries carried over in previous signatures", () => {
+        const base: EChartsOption = {
+          series: [{ id: "flat-white", type: "bar" }],
+        };
+
+        const prev = buildSignature(base);
+        (prev.arrays as Record<string, unknown>).phantom = undefined;
+
+        const result = planUpdate(prev, base);
+
+        expect(result.plan.notMerge).toBe(false);
+        expect(result.plan.replaceMerge).toBeUndefined();
+      });
     });
   });
 });

tests/wc.test.ts

@@ -6,15 +6,11 @@ declare global {
   }
 }
 
-type LoadOptions = { suffix?: string };
-
-const loadModule = (() => {
-  let counter = 0;
-  return async (mode: "stub" | "native", options?: LoadOptions) => {
-    const suffix = options?.suffix ?? `${mode}-${++counter}`;
-    return import(/* @vite-ignore */ `../src/wc?${suffix}`);
-  };
-})();
+const loadModule = async () => {
+  const mod = await import("../src/wc");
+  mod.__resetRegisterState();
+  return mod;
+};
 
 describe("register", () => {
   describe("with stubbed customElements", () => {
@@ -58,7 +54,7 @@ describe("register", () => {
         undefined as unknown as CustomElementRegistry,
       );
 
-      const { register } = await loadModule("stub");
+      const { register } = await loadModule();
 
       expect(register()).toBe(false);
       expect(register()).toBe(false);
@@ -71,7 +67,7 @@ describe("register", () => {
         define() {},
       } as unknown as CustomElementRegistry);
 
-      const { register } = await loadModule("stub", { suffix: "no-get" });
+      const { register } = await loadModule();
       expect(register()).toBe(false);
       expect(register()).toBe(false);
     });
@@ -79,7 +75,7 @@ describe("register", () => {
     it("registers the custom element once", async () => {
       const defineSpy = vi.spyOn(registry, "define");
 
-      const { register, TAG_NAME } = await loadModule("stub");
+      const { register, TAG_NAME } = await loadModule();
 
       expect(register()).toBe(true);
       expect(defineSpy).toHaveBeenCalledTimes(1);
@@ -95,17 +91,17 @@ describe("register", () => {
         throw new Error("boom");
       });
 
-      const { register, TAG_NAME } = await loadModule("stub");
+      const { register, TAG_NAME } = await loadModule();
 
       expect(register()).toBe(false);
-      expect(register()).toBe(false);
+      expect(register()).toBe(false)
       expect(defineSpy).toHaveBeenCalledTimes(1);
       expect(registry.get(TAG_NAME)).toBeUndefined();
     });
 
     it("skips redefinition when element already registered", async () => {
       const existing = class extends HTMLElement {};
-      const { register, TAG_NAME } = await loadModule("stub");
+      const { register, TAG_NAME } = await loadModule();
       registry.define(TAG_NAME, existing);
 
       const defineSpy = vi.spyOn(registry, "define");
@@ -116,7 +112,7 @@ describe("register", () => {
     });
 
     it("exposes a constructor with disconnect hook", async () => {
-      const { register, TAG_NAME } = await loadModule("stub");
+      const { register, TAG_NAME } = await loadModule();
 
       expect(register()).toBe(true);
 
@@ -130,6 +126,7 @@ describe("register", () => {
     let original: CustomElementConstructor | undefined;
 
     beforeEach(() => {
+      vi.resetModules();
       vi.restoreAllMocks();
       vi.unstubAllGlobals();
       original = customElements.get("x-vue-echarts");
@@ -144,7 +141,7 @@ describe("register", () => {
     });
 
     it("disposes chart when element is removed from DOM", async () => {
-      const { register, TAG_NAME } = await loadModule("native");
+      const { register, TAG_NAME } = await loadModule();
 
       expect(register()).toBe(true);