1 files changed, 140 insertions, 0 deletions
diff --git a/utils/js2common.js b/utils/js2common.js
new file mode 100755
index 0000000..aeba49d
--- /dev/null
+++ b/utils/js2common.js
@@ -0,0 +1,140 @@
+#!/usr/bin/env node
+
+const path = require('path');
+const program = require('commander');
+const fs = require('fs');
+const fse = require('fs-extra');
+const babel = require('@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);