Sanitize JS code to avoid Babel helpers (#142)

Author: petermuessig

tools/builder/prepare-gh-pages.js

@@ -7,6 +7,8 @@ const execute = utils.promisify(exec);
 const archiver = require("archiver");
 const fg = require('fast-glob');
 
+const sanitize = require("./sanitze");
+
 const cwd = process.cwd();
 
 function zipDirectory(sourceDir, outPath) {
@@ -127,9 +129,7 @@ function zipDirectory(sourceDir, outPath) {
 						mkdirSync(dirname(targetJS), { recursive: true });
 						// rewrite content of the JS file
 						let content = readFileSync(sourceJS, { encoding: "utf8" });
-						content = content.replaceAll(/\/\*\*.*[\n\s]+\* @namespace.*[\n\s]+\*\/[\n\s]+/g, "");
-						content = content.replaceAll(/\/\*\*.*[\n\s]+\* @name.*[\n\s]+\*\/[\n\s]+/g, "");
-						content = content.replaceAll(/\/\/# sourceMappingURL=.*[\n\s]+/g, "");
+						content = sanitize(content);
 						writeFileSync(targetJS, content, { encoding: "utf8" });
 					} else {
 						console.error("No JS file found for", source);

tools/builder/sanitze.js

@@ -0,0 +1,110 @@
+const removeFunction = function removeFunction(code, functionName) {
+	if (!code || !functionName) {
+		return code;
+	}
+
+	// match the function start
+	const fnStartRegex = new RegExp(
+		`^[ \t\f\v]*function\\s+${functionName}\\s*\\([^)]*\\)\\s*\\{`,
+		"gm"
+	);
+
+	// find the closing brace for the function and remove the function
+	let match;
+	while ((match = fnStartRegex.exec(code)) !== null) {
+		let startIndex = match.index;
+		let braceIndex = code.indexOf("{", match.index);
+		let depth = 0;
+		let i = braceIndex;
+		for (; i < code.length; i++) {
+			if (code[i] === "{") {
+				depth++;
+			} else if (code[i] === "}") {
+				depth--;
+			}
+			if (depth === 0) {
+				// found the matching }
+				break;
+			}
+		}
+		if (depth === 0 && i > braceIndex) {
+			// also include trailing whitespace / newlines after function
+			let endIndex = i + 1;
+			while (endIndex < code.length && /\n/.test(code[endIndex])) {
+				endIndex++;
+			}
+			code = code.slice(0, startIndex) + code.slice(endIndex);
+			fnStartRegex.lastIndex = startIndex;
+		}
+	}
+
+	return code;
+}
+
+/**
+ * the  code sanitization function is used to remove the _interopRequireDefault function
+ * and replace the parameters in the sap.ui.define function with the variables that were
+ * assigned using _interopRequireDefault.
+ * It also removes the __ui5_require_async function and replaces it with sap.ui.require.
+ * @param {string} code the code to sanitize
+ * @returns sanitized code
+ */
+module.exports = function sanitze(code = "") {
+
+	// remove all comments related to UI5 TypeScript generation (namespaces, names)
+	code = code.replaceAll(/\/\*\*.*[\n\s]+\* @namespace.*[\n\s]+\*\/[\n\s]+/g, "");
+	code = code.replaceAll(/\/\*\*.*[\n\s]+\* @name.*[\n\s]+\*\/[\n\s]+/g, "");
+
+	// remove all comments related to source maps
+	code = code.replaceAll(/\/\/# sourceMappingURL=.*[\n\s]+/g, "");
+
+	// remove _interopRequireDefault function
+	code = removeFunction(code, "_interopRequireDefault");
+
+	// find which variables are assigned using _interopRequireDefault
+	let matchedVars;
+	code = code.replace(/^(\s*)(?:var|const|let)\s+(\w+)\s*=\s*_interopRequireDefault\((\w+)\);\s*(.*)\n/gm, (all, spacing, varName, requiredVarName, comment) => {
+		matchedVars ??= {};
+		matchedVars[requiredVarName] = varName;
+		return comment?.trim() ? `${spacing}${comment}\n` : "";
+	});
+
+	// selectively rename only these parameters
+	if (matchedVars) {
+	code = code.replace(
+		/sap\.ui\.define\(\s*(\[[^\]]*\])\s*,\s*function\s*\(([^)]*)\)/g,
+		(all, deps, params) => {
+			const newParams = params
+				.split(",")
+				.map((param) => {
+					return matchedVars[param.trim()] || param.trim();
+				})
+				.join(", ");
+			return `sap.ui.define(${deps}, function (${newParams})`;
+		}
+	);
+	}
+
+	// remove the __ui5_require_async function
+	code = removeFunction(code, "__ui5_require_async");
+
+	// replace __ui5_require_async calls with sap.ui.require
+	code = code.replace(
+		/__ui5_require_async\s*\(\s*("[^"]+")\s*\);/g,
+		"sap.ui.require([$1]);"
+	);
+
+	// replace the class member function classic syntax with the shorthand syntax
+	code = code.replace(/(\w+)\s*:\s*function\s+\w+\s*\(/g, '$1(');
+
+	// replace the async class member function classic syntax with the shorthand syntax
+	code = code.replace(/(\w+)\s*:\s*async\s+function\s+\w+\s*\(/g, 'async $1(');
+
+	// remove the __exports variable and return the exports directly
+	code = code.replace(/(?:var|const|let)\s+__exports\s*=\s*({[\s\S]*?});\s*return\s+__exports\s*;/g, 'return $1;');
+
+	// remove empty lines
+	code = code.replace(/^\s*;\s*\n/gm, "");
+
+	return code;
+};