Require class properties transform when compiling class with private fields

packages/babel-plugin-transform-classes/src/transformClass.ts

@@ -214,7 +214,7 @@ export default function transformClass(
     for (const path of classBodyPaths) {
       const node = path.node;
 
-      if (path.isClassProperty()) {
+      if (path.isClassProperty() || path.isClassPrivateProperty()) {
         throw path.buildCodeFrameError("Missing class properties transform.");
       }
 

packages/babel-plugin-transform-classes/test/fixtures/misc/missing-class-properties-transform-private/input.js

@@ -0,0 +1,7 @@
+class Test {
+  #key = '';
+
+  method() {
+      return this.#key;
+  }
+}

packages/babel-plugin-transform-classes/test/fixtures/misc/missing-class-properties-transform-private/options.json

@@ -0,0 +1,4 @@
+{
+  "plugins": ["transform-classes"],
+  "throws": "Missing class properties transform."
+}

packages/babel-plugin-transform-classes/test/fixtures/misc/missing-class-properties-transform-public/input.js

@@ -0,0 +1,7 @@
+class Test {
+  key = '';
+
+  method() {
+      return this.key;
+  }
+}

packages/babel-plugin-transform-classes/test/fixtures/misc/missing-class-properties-transform-public/options.json

@@ -0,0 +1,4 @@
+{
+  "plugins": ["transform-classes"],
+  "throws": "Missing class properties transform."
+}