# `react-doctor/query-no-mutation-in-effect-as-read`

Mutation driven from an effect as a read

- **Category:** Bugs
- **Severity:** warn
- **Source:** oxlint-plugin-react-doctor
- **Framework:** tanstack-query
- **Enabled when:** tanstack-query

## Validate the diagnostic

Confirm the reported code matches this rule before you edit it.

Confirm the reported code matches `react-doctor/query-no-mutation-in-effect-as-read`. Compare it with the Before example and verify the same API, framework, and execution context. Treat it as a false positive only when one of those conditions differs.

## Compare the code

The corrected pattern shows a focused way to address the diagnostic.

### Reported pattern

```tsx
import { useMutation } from "@tanstack/react-query";
import { useEffect } from "react";

const Team = ({ teamId }) => {
  const users = useMutation({ mutationFn: fetchUsers });
  useEffect(() => {
    users.mutate(teamId);
  }, [teamId]);
  return <UserList users={users.data} />;
};
```

### Corrected pattern

```tsx
import { useQuery } from "@tanstack/react-query";

const Team = ({ teamId }) => {
  const users = useQuery({
    queryKey: ["users", teamId],
    queryFn: () => fetchUsers(teamId),
    enabled: Boolean(teamId),
  });
  return <UserList users={users.data} />;
};
```

## How to fix

Use the corrected pattern as a reference. Preserve behavior that the rule does not require you to change.

### Copyable fix prompt

Copy this self-contained prompt into your coding agent after you confirm the diagnostic.

````text
Fix every confirmed `react-doctor/query-no-mutation-in-effect-as-read` diagnostic in the current repository.

Required change:
- Use `useQuery` with a `queryKey` and `enabled` for reads started by an effect so the result is cached and deduplicated.

Reference transformation:

Before:
```tsx
import { useMutation } from "@tanstack/react-query";
import { useEffect } from "react";

const Team = ({ teamId }) => {
  const users = useMutation({ mutationFn: fetchUsers });
  useEffect(() => {
    users.mutate(teamId);
  }, [teamId]);
  return <UserList users={users.data} />;
};
```

After:
```tsx
import { useQuery } from "@tanstack/react-query";

const Team = ({ teamId }) => {
  const users = useQuery({
    queryKey: ["users", teamId],
    queryFn: () => fetchUsers(teamId),
    enabled: Boolean(teamId),
  });
  return <UserList users={users.data} />;
};
```

Constraints:
- Confirm the reported code matches the Before pattern.
- Make the smallest change that fixes the root cause.
- Preserve behavior and interfaces unrelated to this diagnostic.
- Reuse existing project components, utilities, and conventions.
- Do not introduce render-phase side effects, render-phase state updates, or Hooks rule violations.
- Adapt identifiers and framework details instead of copying blindly.
- Do not disable the rule or suppress matching code.
- Confirm this rule is enabled for the project: `tanstack-query`.

Verification:
- Run focused tests for the changed behavior.
- Run React Doctor and confirm this diagnostic no longer appears.
- Report the files changed and any checks you could not run.
````