Added useCallback to README.md, added loading state

[bence-toth]

Fixes #58.

Fixes #59.

[Copilot]

Pull request overview

This PR updates react-hook-geolocation to expose an isLoading flag from useGeolocation, and updates documentation to recommend wrapping the optional callback in useCallback to avoid render loops.

Changes:

• Added isLoading to the hook return object and updated tests accordingly.
• Updated README usage examples to include a loading UI branch and recommend useCallback for the update callback.
• Bumped package version to 1.2.0.

Reviewed changes

Copilot reviewed 4 out of 6 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/index.js	Adds initial error/isLoading initialization and updates state updates to include isLoading; introduces a new loading-related effect.
src/index.test.js	Updates expectations to include isLoading and adds unsupported-geolocation expectations.
src/index.d.ts	Extends the public return type with isLoading.
README.md	Documents loading-state usage and recommends useCallback for the optional callback parameter.
package.json	Bumps library version to 1.2.0.

Suppressed comments (2)

src/index.js:23

• isLoading is initialized using navigator.geolocation without a typeof navigator guard, which can also break SSR/non-browser usage. Initialize it with the same guarded check used for support detection.

    isLoading: navigator.geolocation !== undefined && isEnabled,

src/index.js:67

• updateCoordinates is memoized with [callback], so any non-memoized callback passed from a component will change on every render and can cause the geolocation effect to resubscribe repeatedly (the behavior reported in #58). If this PR intends to fix #58 (not just document a workaround), consider storing the callback in a useRef and making updateCoordinates stable so the hook does not depend on callback identity.

    },
    [callback]
  );

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[Copilot]

Fixed — the effect now unconditionally calls setCoordinates, setting isLoading to isEnabled && typeof navigator !== "undefined" && navigator.geolocation !== undefined. This prevents isLoading: true when geolocation is unsupported and also clears isLoading when isEnabled flips to false.

[Copilot]

Fixed — added import { useCallback } from "react"; to the code block.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 6 changed files in this pull request and generated no new comments.

Suppressed comments (5)

src/index.js:21

• The initial state sets error to a new Error when navigator is undefined. In SSR/non-browser rendering this will produce an immediate error state (and can cause hydration/UI mismatches) even though geolocation support is only knowable in the browser. Consider treating navigator being undefined as "unknown" and leaving error as null, while still returning an Error when navigator exists but navigator.geolocation is missing.

    error:
      typeof navigator !== "undefined" && navigator.geolocation !== undefined
        ? null
        : new Error(
            "The acquisition of the geolocation information failed due to the lack of user agent support."

README.md:79

• The callback example calls useCallback at the top level of the module. useCallback is a React Hook and must be called inside a React component or a custom hook; otherwise this snippet will trigger an "Invalid hook call" at runtime.

const onGeolocationUpdate = useCallback((geolocation) => {
  console.log("Here’s some new data from the Geolocation API: ", geolocation);
}, []);

const geolocation = useGeolocation({}, onGeolocationUpdate);

README.md:70

• The PR description claims to fix issue #58 (infinite renders when providing a callback). The README now recommends useCallback, but the hook implementation still treats callback as an effect dependency, so passing a non-memoized inline callback can still cause repeated re-subscriptions and render loops. If the intent is to truly fix #58 in-library, consider storing the callback in a ref (or similar) so the geolocation subscription doesn’t depend on callback identity.

To prevent unnecessary renders you can wrap your callback function in a `useCallback` hook to preserve its referential safety.

If you don’t use `PositionOptions`, I recommend that you supply `{}` as your first argument.

src/index.test.js:53

• The new isLoading state is only asserted as false in the existing tests. There’s no test that verifies isLoading: true is exposed while awaiting the first position read (i.e., before success/error callbacks run), which is the main new behavior this PR introduces.

      expect(result.current).toStrictEqual({
        ...mockCoordinates,
        timestamp: undefined,
        error: null,
        isLoading: false,
      });

package.json:3

• The version bump to 1.2.0 accompanies behavior/API changes (new isLoading property and error now potentially being a generic Error for unsupported environments). If consumers relied on error being null when unsupported, this could be a breaking change and may warrant a major version bump (or a clearer changelog note).

  "version": "1.2.0",