add basic build script

langserver/build.js

@@ -0,0 +1,112 @@
+/**
+ * This is a really basic module packer. It simply loads all the modules into a
+ * single object, appends a simple bootstrap require function to 'load' the modules at
+ * runtime and then writes the result out to a entry module.
+ * 
+ * - Each local module (i.e not in node_modules) must be a relative path starting with . or ..
+ * - Subfolders are allowed, but only js files are included.
+ */
+
+/** These are the sources (files and folders) we want to pack */
+const sources = [
+    'completions.js',
+    'doc-formatter.js',
+    'document.js',
+    'java',
+    'logging.js',
+    'method-signatures.js',
+    'server.js',
+    'settings.js'
+]
+
+/** The entry module - must have a relative path */
+const entry = './server.js';
+
+const fs = require('fs');
+const modules = [];
+
+while (sources.length) {
+    const source = sources.shift();
+    const stat = fs.statSync(source);
+    if (stat.isDirectory()) {
+        fs.readdirSync(source).forEach(entry => {
+            sources.unshift(`${source}/${entry}`);
+        })
+        continue;
+    }
+    if (!source.endsWith('.js')) {
+        console.log(`ignoring non-js file: ${source}`);
+        continue;
+    }
+    // add an object entry of the form: 'path': (...) => { file_content }
+    modules.push(`'${source}':
+(require,module,exports) => {
+${fs.readFileSync(source, 'utf8')}
+}`
+    );
+}
+
+/**
+ * The bootstrap contains the custom require function and the call to load
+ * the initial module - it's everything after the marker below
+ */
+const bootstrap = fs.readFileSync(__filename, 'utf8').split('/* bootstrap marker */').pop();
+
+fs.writeFileSync(entry,
+`const data = {
+${modules.join(',\n')}
+}
+${bootstrap}
+_require('${entry}');
+`);
+
+/* bootstrap marker */
+
+const module_stack = [{
+    path: [],
+    name: '',
+}]
+
+const loadedModules = new Set();
+
+function _require(filename) {
+    // local modules always have a relative path
+    if (!filename.startsWith('.')) {
+        // node_modules import
+        return require(filename);
+    }
+    const new_path = module_stack[0].path.slice();
+    let key = filename.replace(/(\.js)?$/, '.js');
+    for (let m; m = key.match(/^\.\.?\//);) {
+        key = key.slice(m[0].length);
+        if (m[0] === '../') {
+            new_path.pop();
+        }
+    }
+    key = [...new_path, key].join('/');
+
+    if (!Object.prototype.hasOwnProperty.call(data, key)) {
+        throw new Error(`Missing module: ${key}`);
+    }
+
+    const entry = data[key];
+
+    if (loadedModules.has(key)) {
+        return entry;
+    }
+
+    const path_parts = key.split(/[\\/]/);
+
+    module_stack.unshift({
+        name: path_parts.pop(),
+        path: path_parts,
+    })
+    const mod = {
+        exports: {},
+    }
+    entry(_require, mod, mod.exports);
+    module_stack.shift();
+
+    loadedModules.add(key);
+    return data[key] = mod.exports;
+}