Paranoia about JSX runtime

Author: eps1lon

scripts/jest/preprocessor.js

@@ -80,7 +80,19 @@ module.exports = {
 
       // This is only for React DevTools tests with React 16.x
       // `react/jsx-dev-runtime` and `react/jsx-runtime` are included in the package starting from v17
-      if (semver.gte(ReactVersionTestingAgainst, '17.0.0')) {
+      // Technically 16.14 and 15.7 have the new runtime but we're not testing those versions.
+      if (
+        semver.gte(ReactVersionTestingAgainst, '15.0.0') &&
+        semver.lt(ReactVersionTestingAgainst, '17.0.0')
+      ) {
+        plugins.push(
+          [
+            require.resolve('@babel/plugin-transform-react-jsx'),
+            {runtime: 'classic'},
+          ],
+          require.resolve('@babel/plugin-transform-react-jsx-source')
+        );
+      } else {
         plugins.push([
           process.env.NODE_ENV === 'development'
             ? require.resolve('@babel/plugin-transform-react-jsx-development')
@@ -89,14 +101,6 @@ module.exports = {
           // would be React.createElement.
           {runtime: 'automatic'},
         ]);
-      } else {
-        plugins.push(
-          [
-            require.resolve('@babel/plugin-transform-react-jsx'),
-            {runtime: 'classic'},
-          ],
-          require.resolve('@babel/plugin-transform-react-jsx-source')
-        );
       }
 
       plugins.push(pathToTransformLazyJSXImport);