**Feature:** Add support for validators that are promise-based or throw errors

.gitignore

@@ -93,6 +93,9 @@ typings/
 public
 lib
 
+# Cache for parcel serverl in example
+.cache
+
 # Files managed by operational-scripts
 tslint.json
 tsconfig.json

example/README.md

@@ -0,0 +1 @@
+This is a simple live demo of `restul-react` components primarily used to test features. Run it with `npm run example`.

example/index.html

@@ -0,0 +1,2 @@
+<div id="app"></div>
+<script src="index.tsx"></script>

example/index.tsx

@@ -0,0 +1,32 @@
+import * as React from "react";
+import { render } from "react-dom";
+
+import { Get, RestfulProvider } from "../src";
+
+const wait = timeout =>
+  new Promise((resolve, reject) => {
+    setTimeout(() => {
+      resolve();
+    }, timeout);
+  });
+
+const App: React.SFC<{}> = props => (
+  <RestfulProvider base="https://dog.ceo">
+    <Get path="/api/breeds/list/all" resolve={res => wait(1500).then(() => Promise.resolve(Object.keys(res.message)))}>
+      {(breeds, { loading, error }) => {
+        if (loading) {
+          return "loading..";
+        }
+        if (error) {
+          return <code>{JSON.stringify(error)}</code>;
+        }
+        if (breeds) {
+          return <ul>{breeds.map((breed, breedIndex) => <li key={breedIndex}>{breed}</li>)}</ul>;
+        }
+        return null;
+      }}
+    </Get>
+  </RestfulProvider>
+);
+
+render(<App />, document.querySelector("#app"));

package.json

@@ -31,6 +31,7 @@
   },
   "scripts": {
     "start": "operational-scripts start",
+    "example": "parcel example/index.html",
     "test": "operational-scripts test",
     "build": "operational-scripts build --for npm",
     "preversion": "npm run build",
@@ -54,6 +55,7 @@
     "jest-dom": "^1.12.0",
     "lint-staged": "^7.2.0",
     "nock": "^10.0.0",
+    "parcel": "^1.10.3",
     "prettier": "^1.13.5",
     "react-dom": "^16.4.2",
     "react-testing-library": "^5.0.0",
@@ -64,7 +66,7 @@
     "typescript": "^3.0.3"
   },
   "dependencies": {
-    "lodash": "^4.17.10",
+    "lodash": "^4.17.11",
     "react": "^16.4.1",
     "react-fast-compare": "^2.0.1",
     "url": "^0.11.0"

src/Get.test.tsx

@@ -253,6 +253,68 @@ describe("Get", () => {
       await wait(() => expect(children.mock.calls.length).toBe(2));
       expect(children.mock.calls[1][0]).toEqual({ hello: "world", foo: "bar" });
     });
+
+    it("should transform data with a promise", async () => {
+      nock("https://my-awesome-api.fake")
+        .get("/")
+        .reply(200, { hello: "world" });
+
+      const children = jest.fn();
+      children.mockReturnValue(<div />);
+
+      render(
+        <RestfulProvider base="https://my-awesome-api.fake">
+          <Get path="" resolve={data => Promise.resolve({ ...data, foo: "bar" })}>
+            {children}
+          </Get>
+        </RestfulProvider>,
+      );
+
+      await wait(() => expect(children.mock.calls.length).toBe(2));
+      expect(children.mock.calls[1][0]).toEqual({ hello: "world", foo: "bar" });
+    });
+
+    it("should pass an error when the resolver throws a runtime error", async () => {
+      nock("https://my-awesome-api.fake")
+        .get("/")
+        .reply(200, { hello: "world" });
+
+      const children = jest.fn();
+      children.mockReturnValue(<div />);
+
+      render(
+        <RestfulProvider base="https://my-awesome-api.fake">
+          <Get path="" resolve={data => data.apples.oranges}>
+            {children}
+          </Get>
+        </RestfulProvider>,
+      );
+
+      await wait(() => expect(children.mock.calls.length).toBe(2));
+      expect(children.mock.calls[1][1].error.message).toEqual("RESOLVE_ERROR");
+      expect(children.mock.calls[1][0]).toEqual(null);
+    });
+
+    it("should pass an error when the resolver is a promise that rejects", async () => {
+      nock("https://my-awesome-api.fake")
+        .get("/")
+        .reply(200, { hello: "world" });
+
+      const children = jest.fn();
+      children.mockReturnValue(<div />);
+
+      render(
+        <RestfulProvider base="https://my-awesome-api.fake">
+          <Get path="" resolve={data => Promise.reject("nogood")}>
+            {children}
+          </Get>
+        </RestfulProvider>,
+      );
+
+      await wait(() => expect(children.mock.calls.length).toBe(2));
+      expect(children.mock.calls[1][1].error).toEqual({ message: "RESOLVE_ERROR", data: JSON.stringify("nogood") });
+      expect(children.mock.calls[1][0]).toEqual(null);
+    });
   });
 
   describe("with lazy", () => {
@@ -494,23 +556,18 @@ describe("Get", () => {
           </RestfulProvider>,
         ),
       );
-
       await wait(() => expect(apiCalls).toEqual(1));
     });
-
     it("should call the API only 10 times without debounce", async () => {
       let apiCalls = 0;
       nock("https://my-awesome-api.fake")
         .filteringPath(/test=[^&]*/g, "test=XXX")
         .get("/?test=XXX")
         .reply(200, () => ++apiCalls)
         .persist();
-
       const children = jest.fn();
       children.mockReturnValue(<div />);
-
       const resolve = a => a;
-
       /**
        * A new instance of RestfulProvider is created on every rerender.
        * This will create a new resolve function every time forcing Get to
@@ -524,15 +581,13 @@ describe("Get", () => {
           <Get path="?test=1">{children}</Get>
         </RestfulProvider>,
       );
-
       times(10, i =>
         rerender(
           <RestfulProvider base="https://my-awesome-api.fake" resolve={resolve}>
             <Get path={`?test=${i + 1}`}>{children}</Get>
           </RestfulProvider>,
         ),
       );
-
       expect(apiCalls).toEqual(10);
     });
   });
@@ -543,41 +598,34 @@ describe("Get", () => {
         .get("/")
         .reply(200, () => ++apiCalls)
         .persist();
-
       const children = jest.fn();
       children.mockReturnValue(<div />);
-
       const resolve = a => a;
       const { rerender } = render(
         <RestfulProvider base="https://my-awesome-api.fake" resolve={resolve}>
           <Get path="">{children}</Get>
         </RestfulProvider>,
       );
-
       rerender(
         <RestfulProvider base="https://my-awesome-api.fake" resolve={resolve}>
           <Get path="">{children}</Get>
         </RestfulProvider>,
       );
-
       expect(apiCalls).toEqual(1);
     });
     it("should refetch when base changes", () => {
       let apiCalls = 0;
       nock("https://my-awesome-api.fake")
         .get("/")
         .reply(200, () => ++apiCalls);
-
       const children = jest.fn();
       children.mockReturnValue(<div />);
-
       const resolve = a => a;
       const { rerender } = render(
         <RestfulProvider base="https://my-awesome-api.fake" resolve={resolve}>
           <Get path="">{children}</Get>
         </RestfulProvider>,
       );
-
       nock("https://my-new-api.fake")
         .get("/")
         .reply(200, () => ++apiCalls);
@@ -588,7 +636,6 @@ describe("Get", () => {
           </Get>
         </RestfulProvider>,
       );
-
       expect(apiCalls).toEqual(2);
     });
     it("should refetch when path changes", () => {
@@ -598,23 +645,19 @@ describe("Get", () => {
         .get("/?test=XXX")
         .reply(200, () => ++apiCalls)
         .persist();
-
       const children = jest.fn();
       children.mockReturnValue(<div />);
-
       const resolve = a => a;
       const { rerender } = render(
         <RestfulProvider base="https://my-awesome-api.fake" resolve={resolve}>
           <Get path="/?test=0">{children}</Get>
         </RestfulProvider>,
       );
-
       rerender(
         <RestfulProvider base="https://my-awesome-api.fake" resolve={resolve}>
           <Get path="/?test=1">{children}</Get>
         </RestfulProvider>,
       );
-
       expect(apiCalls).toEqual(2);
     });
     it("should refetch when resolve changes", () => {
@@ -623,17 +666,14 @@ describe("Get", () => {
         .get("/")
         .reply(200, () => ++apiCalls)
         .persist();
-
       const children = jest.fn();
       children.mockReturnValue(<div />);
-
       const providerResolve = a => a;
       const { rerender } = render(
         <RestfulProvider base="https://my-awesome-api.fake" resolve={providerResolve}>
           <Get path="">{children}</Get>
         </RestfulProvider>,
       );
-
       const newResolve = a => a;
       rerender(
         <RestfulProvider base="https://my-awesome-api.fake" resolve={providerResolve}>
@@ -642,7 +682,6 @@ describe("Get", () => {
           </Get>
         </RestfulProvider>,
       );
-
       expect(apiCalls).toEqual(2);
     });
   });

src/Get.tsx

@@ -4,12 +4,13 @@ import * as React from "react";
 import RestfulReactProvider, { InjectedProps, RestfulReactConsumer, RestfulReactProviderProps } from "./Context";
 import { composePath, composeUrl } from "./util/composeUrl";
 import { processResponse } from "./util/processResponse";
+import { resolveData } from "./util/resolveData";
 
 /**
  * A function that resolves returned data from
  * a fetch call.
  */
-export type ResolveFunction<T> = (data: any) => T;
+export type ResolveFunction<T> = ((data: any) => T) | ((data: any) => Promise<T>);
 
 export interface GetDataError<TError> {
   message: string;
@@ -237,7 +238,9 @@ class ContextlessGet<TData, TError> extends React.Component<
       return null;
     }
 
-    this.setState({ loading: false, data: resolve!(data) });
+    const resolved = await resolveData<TData, TError>({ data, resolve });
+
+    this.setState({ loading: false, data: resolved.data, error: resolved.error });
     return data;
   };
 

src/types.ts

@@ -0,0 +1,12 @@
+// Shared types across exported components and utils
+//
+/**
+ * A function that resolves returned data from
+ * a fetch call.
+ */
+export type ResolveFunction<T> = ((data: any) => T) | ((data: any) => Promise<T>);
+
+export interface GetDataError<TError> {
+  message: string;
+  data: TError | string;
+}

src/util/resolveData.ts

@@ -0,0 +1,32 @@
+import { GetDataError, ResolveFunction } from "../types";
+
+export const resolveData = async <TData, TError>({
+  data,
+  resolve,
+}: {
+  data: any;
+  resolve?: ResolveFunction<TData>;
+}): Promise<{ data: TData | null; error: GetDataError<TError> | null }> => {
+  let resolvedData: TData | null = null;
+  let resolveError: GetDataError<TError> | null = null;
+  try {
+    if (resolve) {
+      const resolvedDataOrPromise: TData | Promise<TData> = resolve(data);
+      resolvedData = (resolvedDataOrPromise as { then?: any }).then
+        ? ((await resolvedDataOrPromise) as TData)
+        : (resolvedDataOrPromise as TData);
+    } else {
+      resolvedData = data;
+    }
+  } catch (err) {
+    resolvedData = null;
+    resolveError = {
+      message: "RESOLVE_ERROR",
+      data: JSON.stringify(err),
+    };
+  }
+  return {
+    data: resolvedData,
+    error: resolveError,
+  };
+};