Rollup (#5995)

build-scripts/rollup-plugins/worker-plugin.js

@@ -0,0 +1,148 @@
+// Worker plugin
+// Each worker will include all of its dependencies
+// instead of relying on an importer.
+
+// Forked from v.1.4.1
+// https://github.com/surma/rollup-plugin-off-main-thread
+/**
+ * Copyright 2018 Google Inc. All Rights Reserved.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const rollup = require("rollup");
+const path = require("path");
+const MagicString = require("magic-string");
+
+const defaultOpts = {
+  // A RegExp to find `new Workers()` calls. The second capture group _must_
+  // capture the provided file name without the quotes.
+  workerRegexp: /new Worker\((["'])(.+?)\1(,[^)]+)?\)/g,
+  plugins: ["node-resolve", "commonjs", "babel"],
+};
+
+async function getBundledWorker(workerPath, rollupOptions) {
+  const bundle = await rollup.rollup({
+    ...rollupOptions,
+    input: {
+      worker: workerPath,
+    },
+  });
+  const { output } = await bundle.generate({
+    // Generates cleanest output, we shouldn't have any imports/exports
+    // that would be incompatible with ES5.
+    format: "es",
+    // We should not export anything. This will fail build if we are.
+    exports: "none",
+  });
+
+  let code;
+
+  for (const chunkOrAsset of output) {
+    if (chunkOrAsset.name === "worker") {
+      code = chunkOrAsset.code;
+    } else if (chunkOrAsset.type !== "asset") {
+      throw new Error("Unexpected extra output");
+    }
+  }
+
+  return code;
+}
+
+module.exports = function (opts = {}) {
+  opts = { ...defaultOpts, ...opts };
+
+  let rollupOptions;
+  let refIds;
+
+  return {
+    name: "hass-worker",
+
+    async buildStart(options) {
+      refIds = {};
+      rollupOptions = {
+        plugins: options.plugins.filter((plugin) =>
+          opts.plugins.includes(plugin.name)
+        ),
+      };
+    },
+
+    async transform(code, id) {
+      // Copy the regexp as they are stateful and this hook is async.
+      const workerRegexp = new RegExp(
+        opts.workerRegexp.source,
+        opts.workerRegexp.flags
+      );
+      if (!workerRegexp.test(code)) {
+        return;
+      }
+
+      const ms = new MagicString(code);
+      // Reset the regexp
+      workerRegexp.lastIndex = 0;
+      while (true) {
+        const match = workerRegexp.exec(code);
+        if (!match) {
+          break;
+        }
+
+        const workerFile = match[2];
+        let optionsObject = {};
+        // Parse the optional options object
+        if (match[3] && match[3].length > 0) {
+          // FIXME: ooooof!
+          optionsObject = new Function(`return ${match[3].slice(1)};`)();
+        }
+        delete optionsObject.type;
+
+        if (!new RegExp("^.*/").test(workerFile)) {
+          this.warn(
+            `Paths passed to the Worker constructor must be relative or absolute, i.e. start with /, ./ or ../ (just like dynamic import!). Ignoring "${workerFile}".`
+          );
+          continue;
+        }
+
+        // Find worker file and store it as a chunk with ID prefixed for our loader
+        const resolvedWorkerFile = (await this.resolve(workerFile, id)).id;
+        let chunkRefId;
+        if (resolvedWorkerFile in refIds) {
+          chunkRefId = refIds[resolvedWorkerFile];
+        } else {
+          const source = await getBundledWorker(
+            resolvedWorkerFile,
+            rollupOptions
+          );
+          chunkRefId = refIds[resolvedWorkerFile] = this.emitFile({
+            name: path.basename(resolvedWorkerFile),
+            source,
+            type: "asset",
+          });
+        }
+
+        const workerParametersStartIndex = match.index + "new Worker(".length;
+        const workerParametersEndIndex =
+          match.index + match[0].length - ")".length;
+
+        ms.overwrite(
+          workerParametersStartIndex,
+          workerParametersEndIndex,
+          `import.meta.ROLLUP_FILE_URL_${chunkRefId}, ${JSON.stringify(
+            optionsObject
+          )}`
+        );
+      }
+
+      return {
+        code: ms.toString(),
+        map: ms.generateMap({ hires: true }),
+      };
+    },
+  };
+};