flow like the river

BACK_BACK/node_modules/parcel-bundler/lib/transforms/terser.js

@@ -0,0 +1,77 @@
+"use strict";
+
+var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
+
+var _asyncToGenerator2 = _interopRequireDefault(require("@babel/runtime/helpers/asyncToGenerator"));
+
+const _require = require('terser'),
+      minify = _require.minify;
+
+const SourceMap = require('../SourceMap');
+
+module.exports = /*#__PURE__*/function () {
+  var _ref = (0, _asyncToGenerator2.default)(function* (asset) {
+    yield asset.parseIfNeeded(); // Convert AST into JS
+
+    let source = (yield asset.generate())[0].value;
+    let customConfig = yield asset.getConfig(['.uglifyrc', '.terserrc']);
+    let options = {
+      warnings: true,
+      safari10: true,
+      mangle: {
+        toplevel: !asset.options.scopeHoist
+      }
+    };
+    let sourceMap;
+
+    if (asset.options.sourceMaps) {
+      sourceMap = new SourceMap();
+      options.output = {
+        source_map: {
+          add(source, gen_line, gen_col, orig_line, orig_col, name) {
+            sourceMap.addMapping({
+              source,
+              name,
+              original: {
+                line: orig_line,
+                column: orig_col
+              },
+              generated: {
+                line: gen_line,
+                column: gen_col
+              }
+            });
+          }
+
+        }
+      };
+    }
+
+    if (customConfig) {
+      options = Object.assign(options, customConfig);
+    }
+
+    let result = minify(source, options);
+
+    if (result.error) {
+      throw result.error;
+    }
+
+    if (sourceMap) {
+      if (asset.sourceMap) {
+        asset.sourceMap = yield new SourceMap().extendSourceMap(asset.sourceMap, sourceMap);
+      } else {
+        asset.sourceMap = sourceMap;
+      }
+    } // babel-generator did our code generation for us, so remove the old AST
+
+
+    asset.ast = null;
+    asset.outputCode = result.code;
+    asset.isAstDirty = false;
+  });
+
+  return function (_x) {
+    return _ref.apply(this, arguments);
+  };
+}();