vize:croquis/cf/injected-async-mutation-race

An injected value is mutated from an async task that can race.

Default severity: error
Applies to: Analyzed component graph and the supported facts described below
Automatic fix: None; review related files and apply the repair
Options: No per-code options; supported CLI findings accept severity overrides

import { defineConfig } from "@vizejs/vite-plugin/vite-plus";

export default defineConfig({
  lint: {
    vize: { preset: "incremental", crossFile: true,
      rules: { "croquis/cf/injected-async-mutation-race": "warn" },
    },
  },
});

vp run lint

Shared project files

Use these unchanged files in both Bad and Good. Install the imported packages in the project: Vue, plus vue-router or Pinia where shown. Follow any version-specific support note. The entry root makes the component relationship explicit.

main.ts

import { createApp } from "vue";
import Root from "./StoreProvider.vue";
createApp(Root).mount("#app");

index.html

<div id="app"></div>
<script type="module" src="/main.ts"></script>

api.ts

export async function loadCount(query: string, options?: { signal?: AbortSignal }): Promise<number> {
  const response = await fetch(`/count?q=${encodeURIComponent(query)}`, options);
  return Number(await response.text());
}

CountSummary.vue

<script setup lang="ts">
import { inject } from "vue";
import { StoreKey } from "./keys/store";
const store = inject(StoreKey)!;
</script>
<template><p>{{ store.count }}</p></template>

Bad

CountLoader.vue writes an awaited result directly into the injected store shared with CountSummary.vue, letting stale work affect both consumers.

keys/store.ts

import type { InjectionKey } from "vue";

export interface Store {
  count: number;
}

export const StoreKey: InjectionKey<Store> = Symbol("store");

StoreProvider.vue

<script setup lang="ts">
import { provide, reactive } from "vue";
import CountLoader from "./CountLoader.vue";
import CountSummary from "./CountSummary.vue";
import { StoreKey, type Store } from "./keys/store";

const store = reactive<Store>({ count: 0 });
provide(StoreKey, store);
</script>

<template>
  <CountLoader />
  <CountSummary />
</template>

CountLoader.vue

<script setup lang="ts">
import { loadCount } from "./api";
import { inject, ref, watch } from "vue";
import { StoreKey } from "./keys/store";

const store = inject(StoreKey)!;
const query = ref("");

watch(query, async (value) => {
  store.count = await loadCount(value);
});
</script>

Good

The loader cancels invalidated work and emits only an active result. The provider owns the store mutation through applyLoadedCount.

keys/store.ts

import type { InjectionKey } from "vue";

export interface Store {
  count: number;
}

export const StoreKey: InjectionKey<Store> = Symbol("store");

StoreProvider.vue

<script setup lang="ts">
import { provide, reactive } from "vue";
import CountLoader from "./CountLoader.vue";
import CountSummary from "./CountSummary.vue";
import { StoreKey, type Store } from "./keys/store";

const store = reactive<Store>({ count: 0 });
provide(StoreKey, store);

function applyLoadedCount(count: number) {
  store.count = count;
}
</script>

<template>
  <CountLoader @loaded="applyLoadedCount" />
  <CountSummary />
</template>

CountLoader.vue

<script setup lang="ts">
import { loadCount } from "./api";
import { ref, watch } from "vue";

const emit = defineEmits<{ loaded: [count: number] }>();
const query = ref("");

watch(query, async (value, _oldValue, onCleanup) => {
  const controller = new AbortController();
  let active = true;

  onCleanup(() => {
    active = false;
    controller.abort();
  });

  const count = await loadCount(value, { signal: controller.signal });
  if (active) emit("loaded", count);
});
</script>

The Good files demonstrate the change described above; other diagnostics can still apply to the complete project.

Public explanation

Producer

Cross-file index