Workaround for antlr4 performance issue

dev/fixAntlr4.js

@@ -0,0 +1,18 @@
+/**
+ * The purpose of this script is to modify the configuration.
+ * of the antlr4 dependency. This is necessary as a workaround
+ * in order to avoid performance problems from antlr4.
+ * The fix is taken from https://github.com/antlr/antlr4/pull/4323
+ * This script can be removed when the fix is available as part of
+ * a published NPM package.
+ */
+
+const fs = require('fs-extra');
+const path = require('path');
+
+const antlr4BabelPath = path.join(__dirname, '..', 'node_modules', 'antlr4', '.babelrc');
+const babelContents = {
+  presets: ['@babel/preset-env'],
+  targets: 'defaults'
+};
+fs.writeJSONSync(antlr4BabelPath, babelContents);

package.json

@@ -17,8 +17,10 @@
     "regression": "ts-node regression/run-regression.ts",
     "regression:all": "ts-node regression/run-regression.ts regression/repos-all.txt",
     "prepare": "npm run build",
+    "postinstall": "npm run fixAntlr4",
     "prepublishOnly": "npm run check && npm run fixGrammarTypes",
-    "fixGrammarTypes": "ts-node dev/fixGrammarTypes.ts"
+    "fixGrammarTypes": "ts-node dev/fixGrammarTypes.ts",
+    "fixAntlr4": "node dev/fixAntlr4.js && cd node_modules && cd antlr4 && npm install && npm run build"
   },
   "contributors": [
     "Julia Afeltra <[email protected]>",
@@ -42,7 +44,8 @@
     "dist/**/*.{js,json,d.ts}",
     "dist/ig/files/**/*",
     "dist/utils/init-project/**/*",
-    "antlr/**/*.g4"
+    "antlr/**/*.g4",
+    "dev/fixAntlr4.js"
   ],
   "license": "Apache-2.0",
   "devDependencies": {