flow like the river

BACK_BACK/node_modules/parcel-bundler/lib/visitors/env.js

@@ -0,0 +1,34 @@
+"use strict";
+
+const types = require('@babel/types');
+
+module.exports = {
+  MemberExpression(node, asset) {
+    // Inline environment variables accessed on process.env
+    if (types.matchesPattern(node.object, 'process.env')) {
+      let key = types.toComputedKey(node);
+
+      if (types.isStringLiteral(key)) {
+        let prop = process.env[key.value];
+
+        if (typeof prop !== 'function') {
+          let value = types.valueToNode(prop);
+          morph(node, value);
+          asset.isAstDirty = true;
+          asset.cacheData.env[key.value] = process.env[key.value];
+        }
+      }
+    }
+  }
+
+}; // replace object properties
+
+function morph(object, newProperties) {
+  for (let key in object) {
+    delete object[key];
+  }
+
+  for (let key in newProperties) {
+    object[key] = newProperties[key];
+  }
+}