Retain DOM nodes during streaming SSR updates

src/Components/Web.JS/.yarnrc

@@ -0,0 +1 @@
+workspaces-experimental false

src/Components/Web.JS/Microsoft.AspNetCore.Components.Web.JS.npmproj

@@ -1,11 +1,20 @@
 <Project DefaultTargets="Build">
-  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Directory.Build.props))\Directory.Build.props" />
 
   <PropertyGroup>
     <IsPackable>false</IsPackable>
     <InstallArgs>--check-files</InstallArgs>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <IsUnitTestProject>true</IsUnitTestProject>
+    <TestDependsOnAspNetRuntime>false</TestDependsOnAspNetRuntime>
+
+    <!-- Npm tests don't run on Helix currently, so we need to set this to false to still run the tests on non-Helix -->
+    <BuildHelixPayload>false</BuildHelixPayload>
+  </PropertyGroup>
+
+  <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Directory.Build.props))\Directory.Build.props" />
+
   <ItemGroup>
     <!--
       Ensure files dependent projects expect exist and are up-to-date. Batching in Npm.Common.targets might skip

src/Components/Web.JS/jest.config.js

@@ -0,0 +1,201 @@
+/*
+ * For a detailed explanation regarding each configuration property, visit:
+ * https://jestjs.io/docs/configuration
+ */
+
+module.exports = {
+  // All imported modules in your tests should be mocked automatically
+  // automock: false,
+
+  // Stop running tests after `n` failures
+  // bail: 0,
+
+  // The directory where Jest should store its cached dependency information
+  // cacheDirectory: "C:\\Users\\stevesa\\AppData\\Local\\Temp\\jest",
+
+  // Automatically clear mock calls, instances, contexts and results before every test
+  // clearMocks: false,
+
+  // 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: undefined,
+
+  // The directory where Jest should output its coverage files
+  // coverageDirectory: undefined,
+
+  // An array of regexp pattern strings used to skip coverage collection
+  // coveragePathIgnorePatterns: [
+  //   "\\\\node_modules\\\\"
+  // ],
+
+  // Indicates which provider should be used to instrument code for coverage
+  coverageProvider: "v8",
+
+  // 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: undefined,
+
+  // A path to a custom dependency extractor
+  // dependencyExtractor: undefined,
+
+  // Make calling deprecated APIs throw helpful error messages
+  // errorOnDeprecated: false,
+
+  // The default configuration for fake timers
+  // fakeTimers: {
+  //   "enableGlobally": 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: undefined,
+
+  // A path to a module which exports an async function that is triggered once after all test suites
+  // globalTeardown: undefined,
+
+  // A set of global variables that need to be available in all test environments
+  // globals: {},
+
+  // The maximum amount of workers used to run your tests. Can be specified as % or a number. E.g. maxWorkers: 10% will use 10% of your CPU amount + 1 as the maximum worker number. maxWorkers: 2 will use a maximum of 2 workers.
+  // maxWorkers: "50%",
+
+  // 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",
+  //   "mjs",
+  //   "cjs",
+  //   "jsx",
+  //   "ts",
+  //   "tsx",
+  //   "json",
+  //   "node"
+  // ],
+
+  // A map from regular expressions to module names or to arrays of 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: undefined,
+
+  // Run tests from one or more projects
+  // projects: undefined,
+
+  // Use this configuration option to add custom reporters to Jest
+  reporters: [
+      "default",
+      ["./node_modules/jest-junit/index.js", { "outputDirectory": "../../../artifacts/log/", "outputName": `${process.platform}` + ".components-webjs.junit.xml" }]
+  ],
+
+  // Automatically reset mock state before every test
+  // resetMocks: false,
+
+  // Reset the module registry before running each individual test
+  // resetModules: false,
+
+  // A path to a custom resolver
+  // resolver: undefined,
+
+  // Automatically restore mock state and implementation before every test
+  // restoreMocks: false,
+
+  // The root directory that Jest should scan for tests and modules within
+  // rootDir: undefined,
+
+  // 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: [],
+
+  // The number of seconds after which a test is considered as slow and reported as such in the results.
+  // slowTestThreshold: 5,
+
+  // 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: "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)"
+  // ],
+
+  // 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: undefined,
+
+  // This option allows use of a custom test runner
+  // testRunner: "jest-circus/runner",
+
+  // A map from regular expressions to paths to transformers
+  transform: {
+    '^.+\\.tsx?$': ['@swc/jest'],
+    '^.+\\.jsx?$': ['@swc/jest'],
+  },
+
+  // An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
+  // transformIgnorePatterns: [
+  //   "\\\\node_modules\\\\",
+  //   "\\.pnp\\.[^\\\\]+$"
+  // ],
+
+  // 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: undefined,
+
+  // 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,
+};

src/Components/Web.JS/package.json

@@ -13,23 +13,32 @@
     "clean": "node node_modules/rimraf/bin.js ./dist/Debug ./dist/Release",
     "prebuild": "yarn run clean && yarn install --mutex network --frozen-lockfile || yarn install --mutex network --frozen-lockfile",
     "lint": "eslint -c ./src/.eslintrc.js --ext .ts ./src",
+    "test": "jest",
+    "test:watch": "jest --watch",
+    "test:debug": "node --nolazy --inspect-brk ./node_modules/jest/bin/jest.js --runInBand --colors --verbose",
     "build": "yarn run build:debug && yarn run build:production",
     "build:debug": "cd src && node ../node_modules/webpack-cli/bin/cli.js --mode development --config ./webpack.config.js",
     "build:production": "cd src && node ../node_modules/webpack-cli/bin/cli.js --mode production --config ./webpack.config.js"
   },
   "devDependencies": {
     "@babel/core": "^7.16.7",
     "@babel/preset-env": "^7.16.8",
+    "@jest/globals": "^29.5.0",
     "@microsoft/dotnet-js-interop": "link:../../JSInterop/Microsoft.JSInterop.JS/src",
     "@microsoft/signalr": "link:../../SignalR/clients/ts/signalr",
     "@microsoft/signalr-protocol-msgpack": "link:../../SignalR/clients/ts/signalr-protocol-msgpack",
+    "@swc/core": "^1.3.58",
+    "@swc/jest": "^0.2.26",
     "@types/dotnet": "./@types/dotnet",
     "@types/jsdom": "^16.2.14",
     "@typescript-eslint/eslint-plugin": "^5.26.0",
     "@typescript-eslint/parser": "^5.26.0",
     "eslint": "^8.16.0",
     "eslint-plugin-header": "^3.1.1",
     "inspectpack": "^4.7.1",
+    "jest": "^29.5.0",
+    "jest-environment-jsdom": "^29.5.0",
+    "jest-junit": "^16.0.0",
     "rimraf": "^3.0.2",
     "terser": "^5.14.2",
     "ts-loader": "^9.2.6",

src/Components/Web.JS/src/Boot.Web.ts

@@ -27,7 +27,7 @@ async function boot(options?: Partial<WebStartOptions>): Promise<void> {
   started = true;
   await activateInteractiveComponents(options);
 
-  attachStreamingRenderingListener();
+  attachStreamingRenderingListener(options?.ssr);
 }
 
 async function activateInteractiveComponents(options?: Partial<WebStartOptions>) {

src/Components/Web.JS/src/Platform/SsrStartOptions.ts

@@ -0,0 +1,10 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+export interface SsrStartOptions {
+  /**
+   * If true, does not attempt to preserve DOM nodes when performing dynamic updates to SSR content
+   * (for example, during enhanced navigation or streaming rendering).
+   */
+  disableDomPreservation?: boolean;
+}

src/Components/Web.JS/src/Platform/WebStartOptions.ts

@@ -3,8 +3,10 @@
 
 import { WebAssemblyStartOptions } from './WebAssemblyStartOptions';
 import { CircuitStartOptions } from './Circuits/CircuitStartOptions';
+import { SsrStartOptions } from './SsrStartOptions';
 
 export interface WebStartOptions {
   circuit: CircuitStartOptions;
   webAssembly: WebAssemblyStartOptions;
+  ssr: SsrStartOptions;
 }