fix regression in transform-flow-comments for class properties (#4623)

packages/babel-plugin-transform-flow-comments/src/index.js

@@ -37,6 +37,12 @@ export default function ({ types: t }) {
         }
       },
 
+      // support for `class X { foo: string }` - #4622
+      ClassProperty(path) {
+        let { node, parent } = path;
+        if (!node.value) wrapInFlowComment(path, parent);
+      },
+
       // support `export type a = {}` - #8 Error: You passed path.replaceWith() a falsy node
       "ExportNamedDeclaration|Flow"(path) {
         let { node, parent } = path;

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-prop-values-2/actual.js

@@ -0,0 +1,4 @@
+class X {
+  a: number
+  b: ?string
+}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-prop-values-2/expected.js

@@ -0,0 +1,4 @@
+class X {
+  /*:: a: number*/
+  /*:: b: ?string*/
+}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-prop-values-2/options.json

@@ -0,0 +1,5 @@
+{
+  "plugins": [
+    "transform-flow-comments"
+  ]
+}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-prop-values-3/actual.js

@@ -0,0 +1,5 @@
+class X {
+  a: number = 2
+  b: ?string = '3'
+  c: ?number
+}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-prop-values-3/expected.js

@@ -0,0 +1,7 @@
+class X {
+  constructor() {
+    this.a = 2;
+    this.b = '3';
+  }
+
+}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-prop-values-3/options.json

@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    "transform-flow-comments",
+    "transform-class-properties"
+  ]
+}

packages/babel-plugin-transform-flow-comments/test/fixtures/flow-comments/class-prop-values/expected.js

@@ -1,5 +1,5 @@
 class X {
   foo = 2;
   bar /*: number*/ = 3;
-  baz /*: ?string*/;
+  /*:: baz: ?string*/
 }