feat: initial commit

node_modules/@babel/helpers/scripts/generate-helpers.js

@@ -0,0 +1,207 @@
+/* eslint-disable import/no-extraneous-dependencies */
+import fs from "fs";
+import { join } from "path";
+import { URL, fileURLToPath } from "url";
+import { minify } from "terser";
+import { babel, presetTypescript } from "$repo-utils/babel-top-level";
+import { IS_BABEL_8 } from "$repo-utils";
+import { gzipSync } from "zlib";
+
+import {
+  getHelperMetadata,
+  stringifyMetadata,
+} from "./build-helper-metadata.js";
+
+const HELPERS_FOLDER = new URL("../src/helpers", import.meta.url);
+const IGNORED_FILES = new Set(["package.json", "tsconfig.json"]);
+
+export default async function generateHelpers() {
+  let output = `/*
+ * This file is auto-generated! Do not modify it directly.
+ * To re-generate run 'yarn gulp generate-runtime-helpers'
+ */
+
+import template from "@babel/template";
+import type * as t from "@babel/types";
+
+interface Helper {
+  minVersion: string;
+  ast: () => t.Program;
+  metadata: HelperMetadata;
+}
+
+export interface HelperMetadata {
+  globals: string[];
+  locals: { [name: string]: string[] };
+  dependencies: { [name: string]: string[] };
+  exportBindingAssignments: string[];
+  exportName: string;
+}
+
+function helper(minVersion: string, source: string, metadata: HelperMetadata): Helper {
+  return Object.freeze({
+    minVersion,
+    ast: () => template.program.ast(source, { preserveComments: true }),
+    metadata,
+  })
+}
+
+export { helpers as default };
+const helpers: Record<string, Helper> = {
+  __proto__: null,
+`;
+
+  let babel7extraOutput = "";
+
+  for (const file of (await fs.promises.readdir(HELPERS_FOLDER)).sort()) {
+    if (IGNORED_FILES.has(file)) continue;
+    if (file.startsWith(".")) continue; // ignore e.g. vim swap files
+
+    const [helperName] = file.split(".");
+
+    const isTs = file.endsWith(".ts");
+
+    const filePath = join(fileURLToPath(HELPERS_FOLDER), file);
+    if (!file.endsWith(".js") && !isTs) {
+      console.error("ignoring", filePath);
+      continue;
+    }
+
+    let code = await fs.promises.readFile(filePath, "utf8");
+    const minVersionMatch = code.match(
+      /^\s*\/\*\s*@minVersion\s+(?<minVersion>\S+)\s*\*\/\s*$/m
+    );
+    if (!minVersionMatch) {
+      throw new Error(`@minVersion number missing in ${filePath}`);
+    }
+    const { minVersion } = minVersionMatch.groups;
+
+    const onlyBabel7 = code.includes("@onlyBabel7");
+    const mangleFns = code.includes("@mangleFns");
+    const noMangleFns = [];
+
+    code = babel.transformSync(code, {
+      configFile: false,
+      babelrc: false,
+      filename: filePath,
+      presets: [
+        [
+          presetTypescript,
+          {
+            onlyRemoveTypeImports: true,
+            optimizeConstEnums: true,
+          },
+        ],
+      ],
+      plugins: [
+        /**
+         * @type {import("@babel/core").PluginObj}
+         */
+        ({ types: t }) => ({
+          // These pre/post hooks are needed because the TS transform is,
+          // when building in the old Babel e2e test, removing the
+          // `export { OverloadYield as default }` in the OverloadYield helper.
+          // TODO: Remove in Babel 8.
+          pre(file) {
+            if (!process.env.IS_BABEL_OLD_E2E) return;
+            file.metadata.exportName = null;
+            file.path.traverse({
+              ExportSpecifier(path) {
+                if (path.node.exported.name === "default") {
+                  file.metadata.exportName = path.node.local.name;
+                }
+              },
+            });
+          },
+          post(file) {
+            if (!process.env.IS_BABEL_OLD_E2E) return;
+            if (!file.metadata.exportName) return;
+            file.path.traverse({
+              ExportNamedDeclaration(path) {
+                if (
+                  !path.node.declaration &&
+                  path.node.specifiers.length === 0
+                ) {
+                  path.node.specifiers.push(
+                    t.exportSpecifier(
+                      t.identifier(file.metadata.exportName),
+                      t.identifier("default")
+                    )
+                  );
+                }
+              },
+            });
+          },
+          visitor: {
+            ImportDeclaration(path) {
+              const source = path.node.source;
+              source.value = source.value
+                .replace(/\.ts$/, "")
+                .replace(/^\.\//, "");
+            },
+            FunctionDeclaration(path) {
+              if (
+                mangleFns &&
+                path.node.leadingComments?.find(c =>
+                  c.value.includes("@no-mangle")
+                )
+              ) {
+                const name = path.node.id.name;
+                if (name) noMangleFns.push(name);
+              }
+            },
+          },
+        }),
+      ],
+    }).code;
+    code = (
+      await minify(code, {
+        ecma: 5,
+        mangle: {
+          keep_fnames: mangleFns ? new RegExp(noMangleFns.join("|")) : true,
+        },
+        // The _typeof helper has a custom directive that we must keep
+        compress: {
+          directives: false,
+          passes: 10,
+          unsafe: true,
+          unsafe_proto: true,
+        },
+      })
+    ).code;
+
+    let metadata;
+    // eslint-disable-next-line prefer-const
+    [code, metadata] = getHelperMetadata(babel, code, helperName);
+
+    const helperStr = `\
+  // size: ${code.length}, gzip size: ${gzipSync(code).length}
+  ${JSON.stringify(helperName)}: helper(
+    ${JSON.stringify(minVersion)},
+    ${JSON.stringify(code)},
+    ${stringifyMetadata(metadata)}
+  ),
+`;
+
+    if (onlyBabel7) {
+      if (!IS_BABEL_8()) babel7extraOutput += helperStr;
+    } else {
+      output += helperStr;
+    }
+  }
+
+  output += "};";
+
+  if (babel7extraOutput) {
+    output += `
+
+if (!process.env.BABEL_8_BREAKING) {
+  Object.assign(helpers, {
+    ${babel7extraOutput}
+  });
+}
+`;
+  }
+
+  return output;
+}