Warn when the version specified in transform-runtime doesn't match

babel.config.js

@@ -77,6 +77,7 @@ module.exports = function(api) {
         "@babel/proposal-object-rest-spread",
         { useBuiltIns: true, loose: true },
       ],
+      "@babel/proposal-optional-chaining",
 
       // Explicitly use the lazy version of CommonJS modules.
       convertESM ? ["@babel/transform-modules-commonjs", { lazy: true }] : null,

package.json

@@ -15,6 +15,7 @@
     "@babel/plugin-proposal-class-properties": "^7.4.4",
     "@babel/plugin-proposal-export-namespace-from": "^7.2.0",
     "@babel/plugin-proposal-numeric-separator": "^7.2.0",
+    "@babel/plugin-proposal-optional-chaining": "^7.2.0",
     "@babel/plugin-transform-modules-commonjs": "^7.4.4",
     "@babel/plugin-transform-runtime": "^7.4.4",
     "@babel/preset-env": "^7.4.5",

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

@@ -153,7 +153,14 @@ function buildHelper(
   return babel.transformFromAst(tree, null, {
     presets: [[require("@babel/preset-env"), { modules: false }]],
     plugins: [
-      [transformRuntime, { corejs, useESModules: esm }],
+      [
+        transformRuntime,
+        {
+          corejs,
+          useESModules: esm,
+          version: require("@babel/runtime/package.json").version,
+        },
+      ],
       buildRuntimeRewritePlugin(
         runtimeName,
         path.relative(path.dirname(helperFilename), pkgDirname),

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

@@ -32,6 +32,57 @@ export function hasMinVersion(minVersion, runtimeVersion) {
   );
 }
 
+export function verifyRuntimeVersion(
+  options,
+  moduleName,
+  runtimeVersion,
+  actualRuntimeVersion,
+) {
+  if (!actualRuntimeVersion) return;
+
+  const minActualVersion = semver.minVersion(actualRuntimeVersion).version;
+  const minVersion = semver.minVersion(runtimeVersion).version;
+
+  if (minActualVersion === minVersion) return;
+
+  const fixedOptions = JSON.stringify(
+    {
+      plugins: [
+        [
+          "@babel/plugin-transform-runtime",
+          { ...options, version: minActualVersion },
+        ],
+      ],
+    },
+    null,
+    2,
+  ).replace(/^/gm, "  ".repeat(2));
+
+  if (semver.gt(minActualVersion, minVersion)) {
+    console.warn(
+      `The installed version of "${moduleName}" (${actualRuntimeVersion}) is greater ` +
+        `than the version specified in "@babel/transform-runtime"'s options ` +
+        `(${options.version}). This difference won't cause any problem in runtime ` +
+        `functionality, but it will make your compiled code larger since Babel ` +
+        `can't rely on some new or modified helpers to be present in the installed ` +
+        `"${moduleName}". For this reason, some helpers will be inlined in your code ` +
+        `as if you weren't using "@babel/plugin-transform-runtime", leadng to bigger bundles.\n` +
+        `To fix this problem, you can specify the correct version in ` +
+        `"@babel/transform-runtime"'s options:\n\n${fixedOptions}`,
+    );
+  } else {
+    console.warn(
+      `The installed version of "${moduleName}" (${actualRuntimeVersion}) is lower ` +
+        `than the version specified in "@babel/transform-runtime"'s options ` +
+        `(${options.version}). For this reason, Babel will assume that some helpers ` +
+        `are supported by the installed "${moduleName}" version, even if they ` +
+        `might not actually be present.\n` +
+        `To fix this problem, you must specify the correct version in ` +
+        `"@babel/transform-runtime"'s options:\n\n${fixedOptions}`,
+    );
+  }
+}
+
 // Note: We can't use NodePath#couldBeBaseType because it doesn't support arrays.
 // Even if we added support for arrays, this package needs to be compatible with
 // ^7.0.0 so we can't rely on it.

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

@@ -1,12 +1,13 @@
 import path from "path";
+import fs from "fs";
 import resolve from "resolve";
 import { declare } from "@babel/helper-plugin-utils";
 import { addDefault, isModule } from "@babel/helper-module-imports";
 import { types as t } from "@babel/core";
 
 import getCoreJS2Definitions from "./runtime-corejs2-definitions";
 import getCoreJS3Definitions from "./runtime-corejs3-definitions";
-import { typeAnnotationToString } from "./helpers";
+import { typeAnnotationToString, verifyRuntimeVersion } from "./helpers";
 
 function resolveAbsoluteRuntime(moduleName: string, dirname: string) {
   try {
@@ -27,6 +28,30 @@ function resolveAbsoluteRuntime(moduleName: string, dirname: string) {
   }
 }
 
+function resolveRuntimeVersion(
+  moduleName: string,
+  modulePath: string,
+  dirname: string,
+) {
+  try {
+    const runtimeDir = path.dirname(
+      resolve.sync(`${modulePath}/package.json`, {
+        basedir: dirname,
+      }),
+    );
+    const pkgFilename = path.resolve(runtimeDir, "../../../package.json");
+    const pkg = JSON.parse(fs.readFileSync(pkgFilename, "utf8"));
+
+    return (
+      pkg.dependencies?.[moduleName] ||
+      pkg.devDependencies?.[moduleName] ||
+      pkg.peerDependencies?.[moduleName]
+    );
+  } catch {}
+
+  return null;
+}
+
 function supportsStaticESM(caller) {
   return !!(caller && caller.supportsStaticESM);
 }
@@ -189,6 +214,13 @@ export default declare((api, options, dirname) => {
     );
   }
 
+  verifyRuntimeVersion(
+    options,
+    moduleName,
+    runtimeVersion,
+    resolveRuntimeVersion(moduleName, modulePath, dirname),
+  );
+
   return {
     name: "transform-runtime",
 

packages/babel-plugin-transform-runtime/test/fixtures/absoluteRuntime/relative/output.js

@@ -1,4 +1,4 @@
-var _classCallCheck = require("<CWD>/packages/babel-plugin-transform-runtime/node_modules/@babel/runtime/helpers/classCallCheck");
+var _classCallCheck = require("<CWD>/packages/babel-plugin-transform-runtime/test/node_modules/@babel/runtime/helpers/classCallCheck");
 
 let Foo = function Foo() {
   "use strict";

packages/babel-plugin-transform-runtime/test/fixtures/absoluteRuntime/true/output.js

@@ -1,4 +1,4 @@
-var _classCallCheck = require("<CWD>/packages/babel-plugin-transform-runtime/node_modules/@babel/runtime/helpers/classCallCheck");
+var _classCallCheck = require("<CWD>/packages/babel-plugin-transform-runtime/test/node_modules/@babel/runtime/helpers/classCallCheck");
 
 let Foo = function Foo() {
   "use strict";

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/greater/input.js

@@ -0,0 +1 @@
+;

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/greater/options.json

@@ -0,0 +1,4 @@
+{
+  "validateLogs": true,
+  "plugins": [["transform-runtime", { "version": "7.2.0" }]]
+}

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/greater/output.js

@@ -0,0 +1 @@
+;

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/greater/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "@babel/runtime": "^7.3.0"
+  }
+}

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/greater/stderr.txt

@@ -0,0 +1,13 @@
+The installed version of "@babel/runtime" (^7.3.0) is greater than the version specified in "@babel/transform-runtime"'s options (7.2.0). This difference won't cause any problem in runtime functionality, but it will make your compiled code larger since Babel can't rely on some new or modified helpers to be present in the installed "@babel/runtime". For this reason, some helpers will be inlined in your code as if you weren't using "@babel/plugin-transform-runtime", leadng to bigger bundles.
+To fix this problem, you can specify the correct version in "@babel/transform-runtime"'s options:
+
+    {
+      "plugins": [
+        [
+          "@babel/plugin-transform-runtime",
+          {
+            "version": "7.3.0"
+          }
+        ]
+      ]
+    }

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/lower/input.js

@@ -0,0 +1 @@
+;

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/lower/options.json

@@ -0,0 +1,4 @@
+{
+  "validateLogs": true,
+  "plugins": [["@babel/plugin-transform-runtime", { "version": "7.5.0" }]]
+}

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/lower/output.js

@@ -0,0 +1 @@
+;

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/lower/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "@babel/runtime": "^7.3.0"
+  }
+}

packages/babel-plugin-transform-runtime/test/fixtures/version-warning/lower/stderr.txt

@@ -0,0 +1,13 @@
+The installed version of "@babel/runtime" (^7.3.0) is lower than the version specified in "@babel/transform-runtime"'s options (7.5.0). For this reason, Babel will assume that some helpers are supported by the installed "@babel/runtime" version, even if they might not actually be present.
+To fix this problem, you must specify the correct version in "@babel/transform-runtime"'s options:
+
+    {
+      "plugins": [
+        [
+          "@babel/plugin-transform-runtime",
+          {
+            "version": "7.3.0"
+          }
+        ]
+      ]
+    }

yarn.lock

@@ -317,6 +317,14 @@
     "@babel/helper-plugin-utils" "^7.0.0"
     "@babel/plugin-syntax-optional-catch-binding" "^7.2.0"
 
+"@babel/plugin-proposal-optional-chaining@^7.2.0":
+  version "7.2.0"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-optional-chaining/-/plugin-proposal-optional-chaining-7.2.0.tgz#ae454f4c21c6c2ce8cb2397dc332ae8b420c5441"
+  integrity sha512-ea3Q6edZC/55wEBVZAEz42v528VulyO0eir+7uky/sT4XRcdkWJcFi1aPtitTlwUzGnECWJNExWww1SStt+yWw==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+    "@babel/plugin-syntax-optional-chaining" "^7.2.0"
+
 "@babel/plugin-proposal-unicode-property-regex@^7.4.4":
   version "7.4.4"
   resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-unicode-property-regex/-/plugin-proposal-unicode-property-regex-7.4.4.tgz#501ffd9826c0b91da22690720722ac7cb1ca9c78"
@@ -382,6 +390,13 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.0.0"
 
+"@babel/plugin-syntax-optional-chaining@^7.2.0":
+  version "7.2.0"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-optional-chaining/-/plugin-syntax-optional-chaining-7.2.0.tgz#a59d6ae8c167e7608eaa443fda9fa8fa6bf21dff"
+  integrity sha512-HtGCtvp5Uq/jH/WNUPkK6b7rufnCPLLlDAFN7cmACoIjaOOiXxUt3SswU5loHqrhtqTsa/WoLQ1OQ1AGuZqaWA==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+
 "@babel/plugin-transform-arrow-functions@^7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-transform-arrow-functions/-/plugin-transform-arrow-functions-7.2.0.tgz#9aeafbe4d6ffc6563bf8f8372091628f00779550"