feat: support import.meta.env (#129)

src/babel.ts

@@ -5,6 +5,7 @@ import type {
 } from "@babel/core";
 import { TransformOptions, TRANSFORM_RESULT } from "./types";
 import { TransformImportMetaPlugin } from "./plugins/babel-plugin-transform-import-meta";
+import { importMetaEnvPlugin } from "./plugins/import-meta-env";
 
 export default function transform(opts: TransformOptions): TRANSFORM_RESULT {
   const _opts: BabelTransformOptions & { plugins: PluginItem[] } = {
@@ -25,6 +26,7 @@ export default function transform(opts: TransformOptions): TRANSFORM_RESULT {
       [TransformImportMetaPlugin, { filename: opts.filename }],
       [require("@babel/plugin-syntax-class-properties")],
       [require("@babel/plugin-proposal-export-namespace-from")],
+      [importMetaEnvPlugin],
     ],
   };
 

src/plugins/import-meta-env.ts

@@ -0,0 +1,105 @@
+/**
+ * Based on https://github.com/iendeavor/import-meta-env/tree/main/packages/babel 0.4.2 (MIT)
+
+Modified to use runtime only without dotenv dependency
+
+---
+
+MIT License
+
+Copyright (c) 2021 Ernest
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+ */
+
+import type BabelCore from "@babel/core";
+import type { PluginObj } from "@babel/core";
+
+export const accessor = `process.env`;
+
+const replaceEnvForRuntime = (
+  template: typeof BabelCore.template,
+  property: string
+) => template.expression.ast(`${accessor}.${property}`);
+
+export function importMetaEnvPlugin({ template, types }: any) {
+  return <PluginObj>{
+    name: "@import-meta-env/babel",
+    visitor: {
+      Identifier(path) {
+        if (!types.isIdentifier(path)) {
+          return;
+        }
+
+        // {}.{}
+        if (!types.isMemberExpression(path.parentPath)) {
+          return;
+        }
+        // {}.{}.{}
+        if (!types.isMemberExpression(path.parentPath.node)) {
+          return;
+        }
+        // {}.{}.{}.{}
+        // @ts-ignore
+        if (!types.isMemberExpression(path.parentPath.node.object)) {
+          return;
+        }
+
+        // {}.{}.{}.PROPERTY
+        // @ts-ignore
+        if (path.parentPath.computed) {
+          return;
+        }
+        // @ts-ignore
+        if (!types.isIdentifier(path.parentPath.node.property)) {
+          return;
+        }
+
+        // {}.{}.env.PROPERTY
+        // @ts-ignore
+        if (!types.isIdentifier(path.parentPath.node.object.property)) {
+          return;
+        }
+        // @ts-ignore
+        if (path.parentPath.node.object.property.name !== "env") {
+          return;
+        }
+
+        // import.meta.env.PROPERTY
+        // @ts-ignore
+        if (!types.isMetaProperty(path.parentPath.node.object.object)) {
+          return;
+        }
+        // @ts-ignore
+        if (path.parentPath.node.object.object.property.name !== "meta") {
+          return;
+        }
+        // @ts-ignore
+        if (path.parentPath.node.object.object.meta.name !== "import") {
+          return;
+        }
+
+        path.parentPath.replaceWith(
+          // @ts-ignore
+          replaceEnvForRuntime(template, path.parentPath.node.property.name)
+        );
+      },
+    },
+  };
+}

test/__snapshots__/fixtures.test.ts.snap

@@ -4,6 +4,11 @@ exports[`fixtures > async > stdout 1`] = `"works"`;
 
 exports[`fixtures > circular > stdout 1`] = `"FooBar"`;
 
+exports[`fixtures > env > stdout 1`] = `
+"process.env.TEST true
+import.meta.env.TEST true"
+`;
+
 exports[`fixtures > error-parse > stderr 1`] = `
 "<root>/lib/index.js:2
   throw err; /* ↓ Check stack trace ↓ */

test/fixtures/env/index.ts

@@ -0,0 +1,3 @@
+console.log("process.env.TEST", process.env.TEST);
+// @ts-ignore
+console.log("import.meta.env.TEST", import.meta.env.TEST);