Improve @babel/runtime esm stability (#12883)

packages/babel-plugin-transform-runtime/scripts/build-dist.js

@@ -248,6 +248,7 @@ function buildHelper(
       [transformRuntime, { corejs, version: runtimeVersion }],
       buildRuntimeRewritePlugin(runtimeName, helperName),
       esm ? null : addDefaultCJSExport,
+      esm ? useRelativeImports : null,
     ].filter(Boolean),
     overrides: [
       {
@@ -318,3 +319,18 @@ function addDefaultCJSExport({ template }) {
     },
   };
 }
+
+function useRelativeImports() {
+  const RE = /^@babel\/runtime(?:-corejs[23])?\/helpers\/(?<name>.+)$/;
+
+  return {
+    visitor: {
+      ImportDeclaration(path) {
+        path.node.source.value = path.node.source.value.replace(
+          RE,
+          "../$<name>/_index.mjs"
+        );
+      },
+    },
+  };
+}

packages/babel-plugin-transform-runtime/src/index.js

@@ -88,13 +88,6 @@ export default declare((api, options, dirname) => {
   // TODO(Babel 8): Remove this check, it's always true
   const DUAL_MODE_RUNTIME = "7.13.0";
   const supportsCJSDefault = hasMinVersion(DUAL_MODE_RUNTIME, runtimeVersion);
-  if (supportsCJSDefault && useESModules && !absoluteRuntime) {
-    console.warn(
-      `[@babel/plugin-transform-runtime] The 'useESModules' option is not necessary when using` +
-        ` a @babel/runtime version >= ${DUAL_MODE_RUNTIME} and not using the 'absoluteRuntime'` +
-        ` option, because it automatically detects the necessary module format.`,
-    );
-  }
 
   function has(obj, key) {
     return Object.prototype.hasOwnProperty.call(obj, key);

packages/babel-plugin-transform-runtime/test/fixtures/dual-babel-runtime/useESModules-modern-runtime/stderr.txt

@@ -1 +0,0 @@
-[@babel/plugin-transform-runtime] The 'useESModules' option is not necessary when using a @babel/runtime version >= 7.13.0 and not using the 'absoluteRuntime' option, because it automatically detects the necessary module format.