Initial commit

Author: grug

.gitignore

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+node_modules/
+dist/
+yarn-error.log
+.vscode/

.prettierrc

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+{
+  "singleQuote": true,
+  "trailingComma": "all"
+}

README.md

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 # react-use-fetch-with-redux
+
 React hook to fetch/select data with simple caching
+
+## This hook is for you if you...
+
+- Want to feed a component data from Redux ✅
+- Don't want to make API calls if you already have the data ✅
+- Love hooks ✅
+
+## Installation
+
+With NPM:
+
+```bash
+npm i --save react-use-fetch-with-redux
+```
+
+With Yarn:
+
+```bash
+yarn add react-use-fetch-with-redux
+```
+
+## Usage
+
+You can create your own hook that uses `useFetchWithRedux` to grab data (if needed) and pass it from the Redux store to your components:
+
+**In `useThing.ts`**
+
+```typescript
+import { useFetchWithRedux } from 'react-use-fetch-with-redux';
+import { getThingStart } from './actions/ThingActions'; // getThingStart is an action creator.
+import { getThingSelector } from './selectors/ThingSelector'; // getThingSelector is a selector.
+
+const useThing = () => useFetchWithRedux(getThingsStart, getThingSelector);
+
+export { useThing };
+```
+
+For completeness, this is what `getThingSelector` could look like:
+
+**In `./selectors/ThingSelector.ts`**
+
+```typescript
+import { State } from './types'; // This is the Redux Store type
+
+const getThingSelector = (state: State) => state.thing;
+
+export { getThingSelector };
+```
+
+Finally, piecing it all together, we can now elegantly use our hook in a component.
+
+**In `SomeComponent.tsx`**
+
+```tsx
+import React from 'react';
+import { useThing } from './useThing';
+import { State, Thing } from './types';
+
+const SomeComponent = () => {
+  const thing = useThing<State, Thing>();
+  const Loading = () => <span>Loading...</span>;
+
+  return thing ? <Loading /> : <div>My thing: thing</div>;
+};
+```
+
+## Testing
+
+The project uses Jest for testing, along with [react-hooks-testing-library](https://github.com/testing-library/react-hooks-testing-library) for rendering hooks without explicitly creating harness components.
+
+## Contributing
+
+I welcome all contributions to this project. Please feel free to raise any issues or pull requests as you see fit :)

jest.config.js

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+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+};

package.json

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+{
+  "name": "react-use-fetch-with-redux",
+  "version": "1.0.0",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "files": [
+    "/dist"
+  ],
+  "keywords": [
+    "hooks",
+    "react",
+    "fetch",
+    "redux"
+  ],
+  "repository": "git@github.com:grug/react-use-fetch-with-redux.git",
+  "author": "Dave Cooper <dave@davecooper.org>",
+  "license": "MIT",
+  "scripts": {
+    "test": "jest",
+    "build": "rimraf dist/ && tsc"
+  },
+  "husky": {
+    "hooks": {
+      "pre-commit": "pretty-quick --staged"
+    }
+  },
+  "dependencies": {
+    "react": "^16.12.0",
+    "react-redux": "^7.1.3"
+  },
+  "np": {
+    "contents": "dist"
+  },
+  "devDependencies": {
+    "@testing-library/react": "^9.4.0",
+    "@testing-library/react-hooks": "^3.2.1",
+    "@types/jest": "^24.9.0",
+    "@types/node": "^13.1.7",
+    "@types/react": "^16.9.17",
+    "@types/react-redux": "^7.1.5",
+    "@types/react-test-renderer": "^16.9.1",
+    "husky": "^4.0.10",
+    "jest": "^24.9.0",
+    "react-test-renderer": "^16.12.0",
+    "rimraf": "^3.0.0",
+    "ts-jest": "^24.3.0",
+    "typescript": "^3.7.4",
+    "pretty-quick": "^2.0.1"
+  }
+}

src/index.spec.ts

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+import { renderHook } from '@testing-library/react-hooks';
+import { useSelector, useDispatch } from 'react-redux';
+import { Action } from 'redux';
+import { useFetchWithRedux } from './';
+
+jest.mock('react-redux', () => ({
+  useSelector: jest.fn(),
+  useDispatch: jest.fn(),
+}));
+
+const mockUseSelector = (useSelector as unknown) as jest.Mock;
+const mockUseDispatch = (useDispatch as unknown) as jest.Mock;
+const mockDispatch = jest.fn();
+
+const testAction = (): Action => ({
+  type: 'TEST',
+});
+const testSelector = <T>(value: T) => value;
+
+describe('useFetchWithRedux hook', () => {
+  beforeEach(() => {
+    jest.resetAllMocks();
+    mockUseDispatch.mockImplementation(() => mockDispatch);
+  });
+
+  it('Calls dispatch when value does not exist in state', () => {
+    mockUseSelector.mockImplementation(callback =>
+      callback(testSelector(undefined)),
+    );
+
+    const { result } = renderHook(() =>
+      useFetchWithRedux(testAction, testSelector, false),
+    );
+
+    expect(result.current).toEqual(undefined);
+    expect(mockDispatch).toHaveBeenCalled();
+  });
+
+  it('Returns value from state when it exists and does not dispatch action', () => {
+    mockUseSelector.mockImplementation(callback =>
+      callback(testSelector<number>(7)),
+    );
+
+    const { result } = renderHook(() =>
+      useFetchWithRedux(testAction, testSelector, false),
+    );
+
+    expect(result.current).toEqual(7);
+    expect(mockDispatch).not.toHaveBeenCalled();
+  });
+
+  it('Does not call dispatch if emptyArrayIsFalse = false and selected data is an empty array', () => {
+    mockUseSelector.mockImplementation(callback => callback(testSelector([])));
+
+    const { result } = renderHook(() =>
+      useFetchWithRedux(testAction, testSelector, false),
+    );
+
+    expect(result.current).toEqual([]);
+    expect(mockDispatch).not.toHaveBeenCalled();
+  });
+
+  it('Does call dispatch if emptyArrayIsFalse = true and selected data is an empty array', () => {
+    mockUseSelector.mockImplementation(callback => callback(testSelector([])));
+
+    const { result } = renderHook(() =>
+      useFetchWithRedux(testAction, testSelector, true),
+    );
+
+    expect(result.current).toEqual([]);
+    expect(mockDispatch).toHaveBeenCalled();
+  });
+});

src/index.ts

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+import { useSelector, useDispatch } from 'react-redux';
+import { useEffect } from 'react';
+import { Action } from 'redux';
+
+function useFetchWithRedux<State, Selected>(
+  getDataStart: () => Action,
+  selector: (state: State) => Selected,
+  emptyArrayIsFalse: boolean = false,
+) {
+  const dispatch = useDispatch();
+  const selected = useSelector(selector);
+
+  useEffect(() => {
+    if (
+      !selected ||
+      (emptyArrayIsFalse && Array.isArray(selected) && selected.length === 0)
+    ) {
+      dispatch(getDataStart());
+    }
+  }, [dispatch]);
+
+  return selected;
+}
+
+export { useFetchWithRedux };

tsconfig.json

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+{
+  "compilerOptions": {
+    /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
+    "target": "ES2018" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */,
+    "module": "ESNext" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
+    // "lib": [],                             /* Specify library files to be included in the compilation. */
+    // "allowJs": true,                       /* Allow javascript files to be compiled. */
+    // "checkJs": true,                       /* Report errors in .js files. */
+    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
+    "declaration": true /* Generates corresponding '.d.ts' file. */,
+    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
+    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
+    // "outFile": "./",                       /* Concatenate and emit output to single file. */
+    "outDir": "dist",
+    // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
+    // "composite": true,                     /* Enable project compilation */
+    // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
+    // "removeComments": true,                /* Do not emit comments to output. */
+    // "noEmit": true,                        /* Do not emit outputs. */
+    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
+    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+
+    /* Strict Type-Checking Options */
+    "strict": true /* Enable all strict type-checking options. */,
+    // "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,              /* Enable strict null checks. */
+    // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
+    // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
+    // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
+    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
+    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
+
+    /* Additional Checks */
+    // "noUnusedLocals": true,                /* Report errors on unused locals. */
+    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
+    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
+    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
+
+    /* Module Resolution Options */
+    "moduleResolution": "node" /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */,
+    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
+    // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
+    // "typeRoots": [],                       /* List of folders to include type definitions from. */
+    // "types": [],                           /* Type declaration files to be included in compilation. */
+    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
+    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
+    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
+    // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */
+
+    /* Source Map Options */
+    // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
+    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
+    // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
+    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
+
+    /* Experimental Options */
+    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
+    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
+
+    /* Advanced Options */
+    "forceConsistentCasingInFileNames": true /* Disallow inconsistently-cased references to the same file. */
+  },
+  "include": ["src"],
+  "exclude": ["src/*.spec.ts"]
+}