Replace build script with convert script for module transformation

package.json

@@ -20,7 +20,7 @@
   "scripts": {
     "lint": "eslint app core po/po2js.js po/xgettext-html.js tests utils",
     "test": "karma start karma.conf.cjs",
-    "prepare": "node ./utils/build.js --clean"
+    "prepare": "node ./utils/convert.js --clean"
   },
   "repository": {
     "type": "git",

utils/build.js

@@ -1,74 +0,0 @@
-#!/usr/bin/env node
-import fs from "fs";
-import path from "path";
-import fse from "fs-extra";
-import { program } from "commander";
-import { ensureDir } from "fs-extra";
-import { fileURLToPath } from "url";
-
-program
-    .option("--clean", "clear the lib folder before building")
-    .parse(process.argv);
-
-const __dirname = path.dirname(fileURLToPath(import.meta.url));
-
-// the various important paths
-const paths = {
-    main: path.resolve(__dirname, ".."),
-    core: path.resolve(__dirname, "..", "core"),
-    vendor: path.resolve(__dirname, "..", "vendor"),
-    libDirBase: path.resolve(__dirname, "..", "lib"),
-};
-
-// walkDir *recursively* walks directories trees,
-// calling the callback for all normal files found.
-const walkDir = async (basePath, cb, filter) => {
-    const files = await fs.promises.readdir(basePath);
-    const paths = files.map(filename => path.join(basePath, filename));
-    return Promise.all(
-        paths.map(async (filepath) => {
-            const stats = await fs.promises.lstat(filepath);
-            if (filter !== undefined && !filter(filepath, stats)) return;
-            if (stats.isSymbolicLink()) return;
-            if (stats.isFile()) return cb(filepath);
-            if (stats.isDirectory()) return walkDir(filepath, cb, filter);
-        })
-    );
-};
-
-const makeLibFiles = async () => {
-    fse.ensureDirSync(paths.libDirBase);
-    const outFiles = [];
-
-    const handleDir = async (vendorRewrite, inPathBase, filename) => {
-        const outPath = path.join(
-            paths.libDirBase,
-            path.relative(inPathBase, filename)
-        );
-        if (path.extname(filename) !== ".js") {
-            return; // skip non-javascript files
-        }
-        await ensureDir(path.dirname(outPath));
-        await fs.promises.copyFile(filename, outPath);
-        console.log(`Writing ${outPath}`);
-        outFiles.push(`${outPath}`);
-    };
-    const handler = handleDir.bind(null, false, paths.main);
-    await walkDir(paths.vendor, handler);
-    const handler2 = handleDir.bind(null, true, paths.core);
-    await walkDir(paths.core, handler2);
-    return outFiles;
-};
-const options = program.opts();
-if (options.clean) {
-    console.log(`Removing ${paths.libDirBase}`);
-    fse.removeSync(paths.libDirBase);
-}
-makeLibFiles()
-    .then((outFiles) => {
-        console.log(`Converted ${outFiles.length} files`);
-    })
-    .catch((err) => {
-        console.error(`Failure converting modules: ${err}`);
-        process.exit(1);
-    });

utils/convert.js

@@ -0,0 +1,140 @@
+#!/usr/bin/env node
+
+import path from 'path';
+import { program } from 'commander';
+import fs from 'fs';
+import fse from 'fs-extra';
+import babel from '@babel/core';
+
+program
+    .option('-m, --with-source-maps [type]', 'output source maps when not generating a bundled app (type may be empty for external source maps, inline for inline source maps, or both) ')
+    .option('--clean', 'clear the lib folder before building')
+    .parse(process.argv);
+
+// the various important paths
+const paths = {
+    main: path.resolve(__dirname, '..'),
+    core: path.resolve(__dirname, '..', 'core'),
+    vendor: path.resolve(__dirname, '..', 'vendor'),
+    libDirBase: path.resolve(__dirname, '..', 'lib'),
+};
+
+// util.promisify requires Node.js 8.x, so we have our own
+function promisify(original) {
+    return function promiseWrap() {
+        const args = Array.prototype.slice.call(arguments);
+        return new Promise((resolve, reject) => {
+            original.apply(this, args.concat((err, value) => {
+                if (err) return reject(err);
+                resolve(value);
+            }));
+        });
+    };
+}
+
+const writeFile = promisify(fs.writeFile);
+
+const readdir = promisify(fs.readdir);
+const lstat = promisify(fs.lstat);
+
+const ensureDir = promisify(fse.ensureDir);
+
+const babelTransformFile = promisify(babel.transformFile);
+
+// walkDir *recursively* walks directories trees,
+// calling the callback for all normal files found.
+function walkDir(basePath, cb, filter) {
+    return readdir(basePath)
+        .then((files) => {
+            const paths = files.map(filename => path.join(basePath, filename));
+            return Promise.all(paths.map(filepath => lstat(filepath)
+                .then((stats) => {
+                    if (filter !== undefined && !filter(filepath, stats)) return;
+
+                    if (stats.isSymbolicLink()) return;
+                    if (stats.isFile()) return cb(filepath);
+                    if (stats.isDirectory()) return walkDir(filepath, cb, filter);
+                })));
+        });
+}
+
+function makeLibFiles(sourceMaps) {
+    // NB: we need to make a copy of babelOpts, since babel sets some defaults on it
+    const babelOpts = () => ({
+        plugins: [],
+        presets: [
+            [ '@babel/preset-env',
+              { modules: 'commonjs' } ]
+        ],
+        ast: false,
+        sourceMaps: sourceMaps,
+    });
+
+    fse.ensureDirSync(paths.libDirBase);
+
+    const outFiles = [];
+
+    const handleDir = (vendorRewrite, inPathBase, filename) => Promise.resolve()
+        .then(() => {
+            const outPath = path.join(paths.libDirBase, path.relative(inPathBase, filename));
+
+            if (path.extname(filename) !== '.js') {
+                return;  // skip non-javascript files
+            }
+            return Promise.resolve()
+                .then(() => ensureDir(path.dirname(outPath)))
+                .then(() => {
+                    const opts = babelOpts();
+            // Adjust for the fact that we move the core files relative
+            // to the vendor directory
+                    if (vendorRewrite) {
+                        opts.plugins.push(["import-redirect",
+                                           {"root": paths.libDirBase,
+                                            "redirect": { "vendor/(.+)": "./vendor/$1"}}]);
+                    }
+
+                    return babelTransformFile(filename, opts)
+                        .then((res) => {
+                            console.log(`Writing ${outPath}`);
+                            const {map} = res;
+                            let {code} = res;
+                            if (sourceMaps === true) {
+                    // append URL for external source map
+                                code += `\n//# sourceMappingURL=${path.basename(outPath)}.map\n`;
+                            }
+                            outFiles.push(`${outPath}`);
+                            return writeFile(outPath, code)
+                                .then(() => {
+                                    if (sourceMaps === true || sourceMaps === 'both') {
+                                        console.log(`  and ${outPath}.map`);
+                                        outFiles.push(`${outPath}.map`);
+                                        return writeFile(`${outPath}.map`, JSON.stringify(map));
+                                    }
+                                });
+                        });
+                });
+        });
+
+    Promise.resolve()
+        .then(() => {
+            const handler = handleDir.bind(null, false, paths.main);
+            return walkDir(paths.vendor, handler);
+        })
+        .then(() => {
+            const handler = handleDir.bind(null, true, paths.core);
+            return walkDir(paths.core, handler);
+        })
+        .catch((err) => {
+            console.error(`Failure converting modules: ${err}`);
+            process.exit(1);
+        });
+}
+
+let options = program.opts();
+
+if (options.clean) {
+    console.log(`Removing ${paths.libDirBase}`);
+    fse.removeSync(paths.libDirBase);
+}
+
+makeLibFiles(options.withSourceMaps);