test: add jest testing

jest.config.js

@@ -0,0 +1,186 @@
+// For a detailed explanation regarding each configuration property, visit:
+// https://jestjs.io/docs/en/configuration.html
+
+module.exports = {
+  // All imported modules in your tests should be mocked automatically
+  // automock: false,
+
+  // Stop running tests after `n` failures
+  // bail: 0,
+
+  // Respect "browser" field in package.json when resolving modules
+  // browser: false,
+
+  // The directory where Jest should store its cached dependency information
+  // cacheDirectory: "",
+
+  // Automatically clear mock calls and instances between every test
+  clearMocks: true,
+
+  // Indicates whether the coverage information should be collected while executing the test
+  // collectCoverage: false,
+
+  // An array of glob patterns indicating a set of files for which coverage information should be collected
+  collectCoverageFrom: ['src/**/*.ts?(x)'],
+
+  // The directory where Jest should output its coverage files
+  coverageDirectory: 'coverage',
+
+  // An array of regexp pattern strings used to skip coverage collection
+  // coveragePathIgnorePatterns: [
+  //   "\\\\node_modules\\\\"
+  // ],
+
+  // A list of reporter names that Jest uses when writing coverage reports
+  // coverageReporters: [
+  //   "json",
+  //   "text",
+  //   "lcov",
+  //   "clover"
+  // ],
+
+  // An object that configures minimum threshold enforcement for coverage results
+  // coverageThreshold: null,
+
+  // A path to a custom dependency extractor
+  // dependencyExtractor: null,
+
+  // Make calling deprecated APIs throw helpful error messages
+  // errorOnDeprecated: false,
+
+  // Force coverage collection from ignored files using an array of glob patterns
+  // forceCoverageMatch: [],
+
+  // A path to a module which exports an async function that is triggered once before all test suites
+  // globalSetup: null,
+
+  // A path to a module which exports an async function that is triggered once after all test suites
+  // globalTeardown: null,
+
+  // A set of global variables that need to be available in all test environments
+  // globals: {},
+
+  // An array of directory names to be searched recursively up from the requiring module's location
+  // moduleDirectories: [
+  //   "node_modules"
+  // ],
+
+  // An array of file extensions your modules use
+  // moduleFileExtensions: [
+  //   "js",
+  //   "json",
+  //   "jsx",
+  //   "ts",
+  //   "tsx",
+  //   "node"
+  // ],
+
+  // A map from regular expressions to module names that allow to stub out resources with a single module
+  // moduleNameMapper: {},
+
+  // An array of regexp pattern strings, matched against all module paths before considered 'visible' to the module loader
+  // modulePathIgnorePatterns: [],
+
+  // Activates notifications for test results
+  // notify: false,
+
+  // An enum that specifies notification mode. Requires { notify: true }
+  // notifyMode: "failure-change",
+
+  // A preset that is used as a base for Jest's configuration
+  preset: 'ts-jest',
+
+  // Run tests from one or more projects
+  // projects: null,
+
+  // Use this configuration option to add custom reporters to Jest
+  // reporters: undefined,
+
+  // Automatically reset mock state between every test
+  // resetMocks: false,
+
+  // Reset the module registry before running each individual test
+  // resetModules: false,
+
+  // A path to a custom resolver
+  // resolver: null,
+
+  // Automatically restore mock state between every test
+  // restoreMocks: false,
+
+  // The root directory that Jest should scan for tests and modules within
+  // rootDir: null,
+
+  // A list of paths to directories that Jest should use to search for files in
+  // roots: [
+  //   "<rootDir>"
+  // ],
+
+  // Allows you to use a custom runner instead of Jest's default test runner
+  // runner: "jest-runner",
+
+  // The paths to modules that run some code to configure or set up the testing environment before each test
+  // setupFiles: [],
+
+  // A list of paths to modules that run some code to configure or set up the testing framework before each test
+  // setupFilesAfterEnv: [],
+
+  // A list of paths to snapshot serializer modules Jest should use for snapshot testing
+  // snapshotSerializers: [],
+
+  // The test environment that will be used for testing
+  // testEnvironment: "jest-environment-jsdom",
+
+  // Options that will be passed to the testEnvironment
+  // testEnvironmentOptions: {},
+
+  // Adds a location field to test results
+  // testLocationInResults: false,
+
+  // The glob patterns Jest uses to detect test files
+  // testMatch: [
+  //   "**/__tests__/**/*.[jt]s?(x)",
+  //   "**/?(*.)+(spec|test).[tj]s?(x)"
+  // ],
+  testMatch: ['**/test/**/?(*.)+(spec|test).[tj]s?(x)']
+
+  // An array of regexp pattern strings that are matched against all test paths, matched tests are skipped
+  // testPathIgnorePatterns: [
+  //   "\\\\node_modules\\\\"
+  // ],
+
+  // The regexp pattern or array of patterns that Jest uses to detect test files
+  // testRegex: [],
+
+  // This option allows the use of a custom results processor
+  // testResultsProcessor: null,
+
+  // This option allows use of a custom test runner
+  // testRunner: "jasmine2",
+
+  // This option sets the URL for the jsdom environment. It is reflected in properties such as location.href
+  // testURL: "http://localhost",
+
+  // Setting this value to "fake" allows the use of fake timers for functions such as "setTimeout"
+  // timers: "real",
+
+  // A map from regular expressions to paths to transformers
+  // transform: null,
+
+  // An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
+  // transformIgnorePatterns: [
+  //   "\\\\node_modules\\\\"
+  // ],
+
+  // An array of regexp pattern strings that are matched against all modules before the module loader will automatically return a mock for them
+  // unmockedModulePathPatterns: undefined,
+
+  // Indicates whether each individual test should be reported during the run
+  // verbose: null,
+
+  // An array of regexp patterns that are matched against all source file paths before re-running tests in watch mode
+  // watchPathIgnorePatterns: [],
+
+  // Whether to use watchman for file crawling
+  // watchman: true,
+}

package.json

@@ -22,14 +22,16 @@
     "build:esm": "shx rm -rf dist/esm && cross-env NODE_ENV=production tsc -p tsconfig.json --module es2015 --target es5 --outDir dist/esm",
     "build:cjs": "shx rm -rf dist/cjs && cross-env NODE_ENV=production tsc -p tsconfig.json --module commonjs --target es5 --outDir dist/cjs",
     "lint": "eslint src/**",
-    "doc": "shx rm -rf typedoc && typedoc src"
+    "doc": "shx rm -rf typedoc && typedoc src",
+    "test": "jest"
   },
   "peerDependencies": {
     "react": ">=16.8.0",
     "react-dom": ">=16.8.0",
     "rxjs": ">=6.0.0"
   },
   "devDependencies": {
+    "@testing-library/react-hooks": "^1.1.0",
     "@types/jest": "^24.0.15",
     "@types/react": "^16.8.23",
     "@types/react-dom": "^16.8.4",
@@ -41,6 +43,7 @@
     "eslint-config-prettier": "^6.0.0",
     "eslint-config-standard": "^13.0.1",
     "eslint-plugin-import": "^2.18.0",
+    "eslint-plugin-jest": "^22.12.0",
     "eslint-plugin-node": "^9.1.0",
     "eslint-plugin-prettier": "^3.1.0",
     "eslint-plugin-promise": "^4.2.1",

test/.eslintrc.js

@@ -0,0 +1,7 @@
+module.exports = {
+  extends: '../.eslintrc',
+  plugins: ['jest'],
+  env: {
+    'jest/globals': true
+  }
+}

test/identity.spec.ts

@@ -0,0 +1,8 @@
+import { identity } from '../src'
+
+describe('identity', () => {
+  it('should return the first argument given', () => {
+    var object = { name: 'CRIMX' }
+    expect(identity(object)).toBe(object)
+  })
+})

test/pluck-current-target-checked.spec.ts

@@ -0,0 +1,18 @@
+import { pluckCurrentTargetChecked } from '../src'
+import { of } from 'rxjs'
+import { toArray } from 'rxjs/operators'
+
+describe('pluckCurrentTargetChecked', () => {
+  it('should pluck the `currentTarget.checked` field from an event', () => {
+    const event$ = of(
+      { currentTarget: { checked: true } },
+      { currentTarget: { checked: false } },
+      { currentTarget: { checked: true } }
+    )
+    const sub = pluckCurrentTargetChecked(event$).pipe(toArray())
+    let result
+    sub.subscribe(value => (result = value))
+    expect(result).toEqual([true, false, true])
+    expect(sub).toBeTruthy()
+  })
+})

test/pluck-current-target-value.spec.ts

@@ -0,0 +1,18 @@
+import { pluckCurrentTargetValue } from '../src'
+import { of } from 'rxjs'
+import { toArray } from 'rxjs/operators'
+
+describe('pluckCurrentTargetValue', () => {
+  it('should pluck the `currentTarget.value` field from an event', () => {
+    const event$ = of(
+      { currentTarget: { value: 1 } },
+      { currentTarget: { value: 2 } },
+      { currentTarget: { value: 3 } }
+    )
+    const sub = pluckCurrentTargetValue(event$).pipe(toArray())
+    let result
+    sub.subscribe(value => (result = value))
+    expect(result).toEqual([1, 2, 3])
+    expect(sub).toBeTruthy()
+  })
+})

test/pluck-first.spec.ts

@@ -0,0 +1,14 @@
+import { pluckFirst } from '../src'
+import { of } from 'rxjs'
+import { toArray } from 'rxjs/operators'
+
+describe('pluckFirst', () => {
+  it('should pluck the first item of an array', () => {
+    const input$ = of<[number, string]>([1, 'a'], [2, 'b'], [3, 'c'])
+    const sub = pluckFirst(input$).pipe(toArray())
+    let result: number[] | undefined
+    sub.subscribe(value => (result = value))
+    expect(result).toEqual([1, 2, 3])
+    expect(sub).toBeTruthy()
+  })
+})

test/use-observable-callback.spec.ts

@@ -0,0 +1,38 @@
+import { useObservableCallback, identity } from '../src'
+import { renderHook } from '@testing-library/react-hooks'
+
+describe('useObservableCallback', () => {
+  it('should call the init function once', () => {
+    const timeSpy = jest.fn(identity)
+    const { rerender } = renderHook(() => useObservableCallback(timeSpy))
+    expect(timeSpy).toBeCalledTimes(1)
+    rerender()
+    expect(timeSpy).toBeCalledTimes(1)
+    rerender()
+    expect(timeSpy).toBeCalledTimes(1)
+  })
+
+  it('should always return the same callback and Observable', () => {
+    const { result, rerender } = renderHook(() =>
+      useObservableCallback<string>(identity)
+    )
+    const firstResult = result.current
+    rerender()
+    expect(firstResult).not.toBe(result.current)
+    expect(result.current).toStrictEqual(firstResult)
+  })
+
+  it('should emit value when the callback is called', () => {
+    const { result } = renderHook(() => useObservableCallback<string>(identity))
+    const [onChange, event$] = result.current
+    const spy = jest.fn()
+    event$.subscribe(spy)
+    expect(spy).toBeCalledTimes(0)
+    onChange('hello')
+    expect(spy).toBeCalledTimes(1)
+    expect(spy).lastCalledWith('hello')
+    onChange('world')
+    expect(spy).toBeCalledTimes(2)
+    expect(spy).lastCalledWith('world')
+  })
+})