Add tests

- This commit adds tests running in both webpack v4 and webpack v5.

- Interestingly, both pass - I expected webpack v5 too fail.

Will investigate

package.json

@@ -139,5 +139,8 @@
     "version-check": "node ./scripts/tasks/version-check.js",
     "merge-fork": "node ./scripts/merge-fork/merge-fork.js",
     "replace-fork": "node ./scripts/merge-fork/replace-fork.js"
+  },
+  "dependencies": {
+    "webpack5": "npm:webpack@5"
   }
 }

packages/react-server-dom-webpack/src/__tests__/ReactFlightWebpackPlugin-test.js

@@ -0,0 +1,136 @@
+const webpack5 = require('webpack5');
+const webpack4 = require('webpack');
+const path = require('path');
+const os = require('os');
+const FlightPlugin = require('../ReactFlightWebpackPlugin').default;
+
+describe('ReactFlightWebpackPlugin', () => {
+  // Probably too big a timeout.
+  jest.setTimeout(5000 * 5);
+
+  test('produces manifest - webpack v4', done => {
+    const entry = path.resolve(path.join(__dirname, 'fixture', 'entry.js'));
+
+    const plugin = new FlightPlugin({isServer: false});
+
+    const output = webpack4({
+      entry,
+      plugins: [plugin],
+      output: {
+        // Output
+        path: path.resolve(path.join(os.tmpdir(), 'output')),
+      },
+      mode: 'development',
+    });
+
+    output.run((err, stats) => {
+      expect(err).toBeNull();
+      const fileName = plugin.manifestFilename; //'react-client-manifest.json'
+
+      const pluginOutput = stats.compilation.assets[fileName];
+      console.log(pluginOutput);
+
+      const producedManifest = pluginOutput.source();
+
+      const manifest = JSON.parse(producedManifest);
+      // The key uses the absolute filename, which means we can't snapshot it.
+      const key =
+        'file://' +
+        path.resolve(path.join(__dirname, 'fixture', 'Form.client.js'));
+
+      expect(manifest[key]).toMatchInlineSnapshot(`
+        Object {
+          "": Object {
+            "chunks": Array [
+              "main",
+            ],
+            "id": "./packages/react-server-dom-webpack/src/__tests__/fixture/Form.client.js",
+            "name": "",
+          },
+          "*": Object {
+            "chunks": Array [
+              "main",
+            ],
+            "id": "./packages/react-server-dom-webpack/src/__tests__/fixture/Form.client.js",
+            "name": "*",
+          },
+          "true": Object {
+            "chunks": Array [
+              "main",
+            ],
+            "id": "./packages/react-server-dom-webpack/src/__tests__/fixture/Form.client.js",
+            "name": true,
+          },
+        }
+      `);
+
+      done();
+    });
+  });
+
+  test('produces manifest - webpack v5', done => {
+    const entry = path.resolve(path.join(__dirname, 'fixture', 'entry.js'));
+
+    const plugin = new FlightPlugin({isServer: false});
+    const fileName = plugin.manifestFilename;
+
+    const output = webpack5({
+      entry: {
+        main: entry,
+        client: path.resolve(path.join(__dirname, 'fixture', 'Form.client.js')),
+      },
+      plugins: [plugin],
+      cache: undefined,
+      output: {
+        // Output
+        path: path.resolve(path.join(os.tmpdir(), 'output')),
+      },
+      mode: 'development',
+    });
+
+    const originalFileSystem = output.outputFileSystem;
+
+    output.outputFileSystem = {
+      ...originalFileSystem,
+      writeFile: (dest, contents, err) => {
+        if (dest.includes(fileName)) {
+          assert(contents.toString());
+          done();
+        }
+      },
+    };
+
+    output.run((err, stats, foo) => {
+      expect(err).toBeNull();
+    });
+  });
+});
+
+function assert(manifestContents) {
+  const key =
+    'file://' + path.resolve(path.join(__dirname, 'fixture', 'Form.client.js'));
+  expect(JSON.parse(manifestContents)[key]).toMatchInlineSnapshot(`
+    Object {
+      "": Object {
+        "chunks": Array [
+          "client",
+        ],
+        "id": "./packages/react-server-dom-webpack/src/__tests__/fixture/Form.client.js",
+        "name": "",
+      },
+      "*": Object {
+        "chunks": Array [
+          "client",
+        ],
+        "id": "./packages/react-server-dom-webpack/src/__tests__/fixture/Form.client.js",
+        "name": "*",
+      },
+      "undefined": Object {
+        "chunks": Array [
+          "client",
+        ],
+        "id": "./packages/react-server-dom-webpack/src/__tests__/fixture/Form.client.js",
+      },
+    }
+  `);
+}

packages/react-server-dom-webpack/src/__tests__/fixture/Form.client.js

@@ -0,0 +1,4 @@
+
+module.exports = function Form() {
+  console.log('Form Rendered!')
+}

packages/react-server-dom-webpack/src/__tests__/fixture/FormServer.server.js

@@ -0,0 +1,4 @@
+
+module.exports = function Form() {
+  console.log('Form Rendered! On the server')
+}

packages/react-server-dom-webpack/src/__tests__/fixture/entry.js

@@ -0,0 +1,8 @@
+
+const ClientComponent = require('./Form.client');
+const ServerComponent = require('./FormServer.server.js');
+
+console.log(
+  ClientComponent,
+  ServerComponent
+);

packages/react-server-dom-webpack/src/__tests__/fixture/package.json

@@ -0,0 +1,3 @@
+{
+  "name": "fixture"
+}