Add explicit error in useDataProvider hook when the dataProvider throws a sync error

docs/DataProviders.md

@@ -637,7 +637,49 @@ export default {
 
 ### Error Format
 
-When the API backend returns an error, the Data Provider should `throw` an `Error` object. This object should contain a `status` property with the HTTP response code (404, 500, etc.). React-admin inspects this error code, and uses it for [authentication](./Authentication.md) (in case of 401 or 403 errors). Besides, react-admin displays the error `message` on screen in a temporary notification.
+When the API backend returns an error, the Data Provider should return a rejected Promise containing an `Error` object. This object should contain a `status` property with the HTTP response code (404, 500, etc.). React-admin inspects this error code, and uses it for [authentication](./Authentication.md) (in case of 401 or 403 errors). Besides, react-admin displays the error `message` on screen in a temporary notification.
+
+If you use `fetchJson`, you don't need to do anything: HTTP errors are automaticlly decorated as expected by react-admin.
+
+If you use another HTTP client, make sure you return a rejected Promise. You can use the `HttpError` class to throw an error with status in one line:
+
+```js
+import { HttpError } from 'react-admin';
+
+export default {
+    getList: (resource, params) => {
+        return new Promise((resolve, reject) => {
+            myApiClient(url, { ...options, headers: requestHeaders })
+                .then(response =>
+                    response.text().then(text => ({
+                        status: response.status,
+                        statusText: response.statusText,
+                        headers: response.headers,
+                        body: text,
+                    }))
+                )
+                .then(({ status, statusText, headers, body }) => {
+                    let json;
+                    try {
+                        json = JSON.parse(body);
+                    } catch (e) {
+                        // not json, no big deal
+                    }
+                    if (status < 200 || status >= 300) {
+                        return reject(
+                            new HttpError(
+                                (json && json.message) || statusText,
+                                status,
+                                json
+                            )
+                        );
+                    }
+                    return resolve({ status, headers, body, json });
+                });
+        }),
+    ...
+}
+```
 
 ## Using The Data Provider In Components
 

packages/ra-core/src/dataProvider/useDataProvider.spec.js

@@ -0,0 +1,206 @@
+import React, { useState, useEffect } from 'react';
+import { cleanup, act } from '@testing-library/react';
+import expect from 'expect';
+
+import renderWithRedux from '../util/renderWithRedux';
+import useDataProvider from './useDataProvider';
+import { DataProviderContext } from '../dataProvider';
+
+const UseGetOne = () => {
+    const [data, setData] = useState();
+    const [error, setError] = useState();
+    const dataProvider = useDataProvider();
+    useEffect(() => {
+        dataProvider
+            .getOne()
+            .then(res => setData(res.data))
+            .catch(e => setError(e));
+    }, [dataProvider]);
+    if (error) return <div data-testid="error">{error.message}</div>;
+    if (data) return <div data-testid="data">{JSON.stringify(data)}</div>;
+    return <div data-testid="loading">loading</div>;
+};
+
+describe('useDataProvider', () => {
+    afterEach(cleanup);
+
+    it('should return a way to call the dataProvider', async () => {
+        const getOne = jest.fn(() =>
+            Promise.resolve({ data: { id: 1, title: 'foo' } })
+        );
+        const dataProvider = { getOne };
+        const { queryByTestId } = renderWithRedux(
+            <DataProviderContext.Provider value={dataProvider}>
+                <UseGetOne />
+            </DataProviderContext.Provider>
+        );
+        expect(queryByTestId('loading')).not.toBeNull();
+        await act(async () => {
+            await new Promise(resolve => setTimeout(resolve));
+        });
+        expect(getOne).toBeCalledTimes(1);
+        expect(queryByTestId('loading')).toBeNull();
+        expect(queryByTestId('data').textContent).toBe(
+            '{"id":1,"title":"foo"}'
+        );
+    });
+
+    it('should handle async errors in the dataProvider', async () => {
+        jest.spyOn(console, 'error').mockImplementationOnce(() => {});
+        const getOne = jest.fn(() => Promise.reject(new Error('foo')));
+        const dataProvider = { getOne };
+        const { queryByTestId } = renderWithRedux(
+            <DataProviderContext.Provider value={dataProvider}>
+                <UseGetOne />
+            </DataProviderContext.Provider>
+        );
+        expect(queryByTestId('loading')).not.toBeNull();
+        await act(async () => {
+            await new Promise(resolve => setTimeout(resolve));
+        });
+        expect(getOne).toBeCalledTimes(1);
+        expect(queryByTestId('loading')).toBeNull();
+        expect(queryByTestId('error').textContent).toBe('foo');
+    });
+
+    it('should throw a meaningful error when the dataProvider throws a sync error', async () => {
+        const c = jest.spyOn(console, 'error').mockImplementation(() => {});
+        const getOne = jest.fn(() => {
+            throw new Error('foo');
+        });
+        const dataProvider = { getOne };
+        const r = () =>
+            renderWithRedux(
+                <DataProviderContext.Provider value={dataProvider}>
+                    <UseGetOne />
+                </DataProviderContext.Provider>
+            );
+        expect(r).toThrow(
+            new Error(
+                'The dataProvider threw an error. It should return a rejected Promise instead.'
+            )
+        );
+        c.mockRestore();
+    });
+
+    it('should dispatch CUSTOM_FETCH actions by default', async () => {
+        const getOne = jest.fn(() => Promise.resolve({ data: null }));
+        const dataProvider = { getOne };
+        const { dispatch } = renderWithRedux(
+            <DataProviderContext.Provider value={dataProvider}>
+                <UseGetOne />
+            </DataProviderContext.Provider>
+        );
+        expect(dispatch.mock.calls).toHaveLength(3);
+        // wait for the dataProvider to return
+        await act(async () => {
+            await new Promise(resolve => setTimeout(resolve));
+        });
+        expect(dispatch.mock.calls).toHaveLength(5);
+        expect(dispatch.mock.calls[0][0].type).toBe('CUSTOM_FETCH');
+        expect(dispatch.mock.calls[1][0].type).toBe('CUSTOM_FETCH_LOADING');
+        expect(dispatch.mock.calls[2][0].type).toBe('RA/FETCH_START');
+        expect(dispatch.mock.calls[3][0].type).toBe('CUSTOM_FETCH_SUCCESS');
+        expect(dispatch.mock.calls[4][0].type).toBe('RA/FETCH_END');
+    });
+
+    describe('options', () => {
+        it('should accept an action option to dispatch a custom action', async () => {
+            const UseGetOneWithCustomAction = () => {
+                const [data, setData] = useState();
+                const dataProvider = useDataProvider();
+                useEffect(() => {
+                    dataProvider
+                        .getOne('dummy', {}, { action: 'MY_ACTION' })
+                        .then(res => setData(res.data));
+                }, [dataProvider]);
+                if (data)
+                    return <div data-testid="data">{JSON.stringify(data)}</div>;
+                return <div data-testid="loading">loading</div>;
+            };
+            const getOne = jest.fn(() => Promise.resolve({ data: null }));
+            const dataProvider = { getOne };
+            const { dispatch } = renderWithRedux(
+                <DataProviderContext.Provider value={dataProvider}>
+                    <UseGetOneWithCustomAction />
+                </DataProviderContext.Provider>
+            );
+            expect(dispatch.mock.calls).toHaveLength(3);
+            // wait for the dataProvider to return
+            await act(async () => {
+                await new Promise(resolve => setTimeout(resolve));
+            });
+            expect(dispatch.mock.calls).toHaveLength(5);
+            expect(dispatch.mock.calls[0][0].type).toBe('MY_ACTION');
+            expect(dispatch.mock.calls[1][0].type).toBe('MY_ACTION_LOADING');
+            expect(dispatch.mock.calls[2][0].type).toBe('RA/FETCH_START');
+            expect(dispatch.mock.calls[3][0].type).toBe('MY_ACTION_SUCCESS');
+            expect(dispatch.mock.calls[4][0].type).toBe('RA/FETCH_END');
+        });
+
+        it('should accept an onSuccess option to execute on success', async () => {
+            const onSuccess = jest.fn();
+            const UseGetOneWithOnSuccess = () => {
+                const [data, setData] = useState();
+                const dataProvider = useDataProvider();
+                useEffect(() => {
+                    dataProvider
+                        .getOne('dummy', {}, { onSuccess })
+                        .then(res => setData(res.data));
+                }, [dataProvider]);
+                if (data)
+                    return <div data-testid="data">{JSON.stringify(data)}</div>;
+                return <div data-testid="loading">loading</div>;
+            };
+            const getOne = jest.fn(() =>
+                Promise.resolve({ data: { id: 1, foo: 'bar' } })
+            );
+            const dataProvider = { getOne };
+            renderWithRedux(
+                <DataProviderContext.Provider value={dataProvider}>
+                    <UseGetOneWithOnSuccess />
+                </DataProviderContext.Provider>
+            );
+            expect(onSuccess.mock.calls).toHaveLength(0);
+            // wait for the dataProvider to return
+            await act(async () => {
+                await new Promise(resolve => setTimeout(resolve));
+            });
+            expect(onSuccess.mock.calls).toHaveLength(1);
+            expect(onSuccess.mock.calls[0][0]).toEqual({
+                data: { id: 1, foo: 'bar' },
+            });
+        });
+
+        it('should accept an onFailure option to execute on failure', async () => {
+            jest.spyOn(console, 'error').mockImplementationOnce(() => {});
+            const onFailure = jest.fn();
+            const UseGetOneWithOnFailure = () => {
+                const [error, setError] = useState();
+                const dataProvider = useDataProvider();
+                useEffect(() => {
+                    dataProvider
+                        .getOne('dummy', {}, { onFailure })
+                        .catch(e => setError(e));
+                }, [dataProvider]);
+                if (error)
+                    return <div data-testid="error">{error.message}</div>;
+                return <div data-testid="loading">loading</div>;
+            };
+            const getOne = jest.fn(() => Promise.reject(new Error('foo')));
+            const dataProvider = { getOne };
+            renderWithRedux(
+                <DataProviderContext.Provider value={dataProvider}>
+                    <UseGetOneWithOnFailure />
+                </DataProviderContext.Provider>
+            );
+            expect(onFailure.mock.calls).toHaveLength(0);
+            // wait for the dataProvider to return
+            await act(async () => {
+                await new Promise(resolve => setTimeout(resolve));
+            });
+            expect(onFailure.mock.calls).toHaveLength(1);
+            expect(onFailure.mock.calls[0][0]).toEqual(new Error('foo'));
+        });
+    });
+});