[core] Make sanity exec use same babel config as studio (#1322)

packages/@sanity/core/src/actions/exec/babel.js

@@ -1,14 +1,28 @@
+import fs from 'fs'
+import path from 'path'
 import registerBabel from '@babel/register'
 
-registerBabel({
-  presets: [
-    [
-      '@babel/preset-env',
-      {
-        targets: {
-          node: 'current'
-        }
-      }
-    ]
-  ]
-})
+function getConfig() {
+  try {
+    // eslint-disable-next-line no-sync
+    const content = fs.readFileSync(path.join(process.cwd(), '.babelrc'))
+    return JSON.parse(content)
+  } catch (err) {
+    return {
+      presets: [
+        require.resolve('@babel/preset-react'),
+        [
+          require.resolve('@babel/preset-env'),
+          {
+            targets: {
+              node: 'current'
+            }
+          }
+        ]
+      ],
+      plugins: [require.resolve('@babel/plugin-proposal-class-properties')]
+    }
+  }
+}
+
+registerBabel(getConfig())

packages/@sanity/core/src/actions/exec/execScript.js

@@ -1,5 +1,5 @@
-const path = require('path')
 const spawn = require('child_process').spawn
+const path = require('path')
 const fse = require('fs-extra')
 
 module.exports = async args => {
@@ -17,7 +17,7 @@ module.exports = async args => {
   }
 
   const babel = require.resolve('./babel')
-  const loader = require.resolve('@sanity/plugin-loader/register')
+  const loader = require.resolve('./pluginLoader')
   const nodeArgs = ['-r', babel, '-r', loader]
     .concat(withToken ? ['-r', require.resolve('./configClient')] : [])
     .concat(scriptPath)

packages/@sanity/core/src/actions/exec/pluginLoader.js

@@ -0,0 +1,3 @@
+const registerLoader = require('@sanity/plugin-loader')
+
+registerLoader({basePath: process.cwd(), stubCss: true})