Implement importInterop: "node" option for module transforms (#12838)

packages/babel-plugin-transform-modules-commonjs/test/importInterop-function.js

@@ -0,0 +1,46 @@
+import * as babel from "@babel/core";
+import transformCommonjs from "../lib";
+import externalHelpers from "@babel/plugin-external-helpers";
+
+it("'importInterop' accepts a function", function () {
+  const code = `
+    import a from "a";
+    import b from "b";
+    import c from "c";
+
+    a();
+    b();
+    c();
+  `;
+
+  const importInterop = source => {
+    if (source === "a") return "babel";
+    else if (source === "b") return "node";
+    else if (source === "c") return "none";
+  };
+
+  const output = babel.transformSync(code, {
+    configFile: false,
+    ast: false,
+    plugins: [
+      [externalHelpers, { helperVersion: "7.100.0" }],
+      [transformCommonjs, { importInterop }],
+    ],
+  }).code;
+
+  expect(output).toMatchInlineSnapshot(`
+    "\\"use strict\\";
+
+    var _a = babelHelpers.interopRequireDefault(require(\\"a\\"));
+
+    var _b = require(\\"b\\");
+
+    var _c = require(\\"c\\");
+
+    (0, _a.default)();
+
+    _b();
+
+    (0, _c.default)();"
+  `);
+});