[preset-typescript] Fix private members type annotations (#11315)

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

@@ -78,7 +78,12 @@ export default declare(
           if (!node.decorators) {
             path.remove();
           }
-        } else if (!allowDeclareFields && !node.value && !node.decorators) {
+        } else if (
+          !allowDeclareFields &&
+          !node.value &&
+          !node.decorators &&
+          !t.isClassPrivateProperty(node)
+        ) {
           path.remove();
         }
 
@@ -325,13 +330,16 @@ export default declare(
           // class transform would transform the class, causing more specific
           // visitors to not run.
           path.get("body.body").forEach(child => {
-            if (child.isClassMethod()) {
+            if (child.isClassMethod() || child.isClassPrivateMethod()) {
               if (child.node.kind === "constructor") {
                 classMemberVisitors.constructor(child, path);
               } else {
                 classMemberVisitors.method(child, path);
               }
-            } else if (child.isClassProperty()) {
+            } else if (
+              child.isClassProperty() ||
+              child.isClassPrivateProperty()
+            ) {
               classMemberVisitors.field(child, path);
             }
           });

packages/babel-plugin-transform-typescript/test/fixtures/class/methods/input.ts

@@ -1,4 +1,5 @@
 class C {
+    #m(x: number): void {}
     m(): void;
     public m(x?: number, ...y: number[]): void {}
     public constructor() {}

packages/babel-plugin-transform-typescript/test/fixtures/class/methods/options.json

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

packages/babel-plugin-transform-typescript/test/fixtures/class/methods/output.js

@@ -1,4 +1,6 @@
 class C {
+  #m(x) {}
+
   m(x, ...y) {}
 
   constructor() {}

packages/babel-plugin-transform-typescript/test/fixtures/class/properties/input.ts

@@ -6,4 +6,6 @@ class C {
     @foo e: number = 3;
     f!: number;
     @foo g!: number;
+    #h: string;
+    #i: number = 10;
 }

packages/babel-plugin-transform-typescript/test/fixtures/class/properties/options.json

@@ -1,3 +1,7 @@
 {
-  "plugins": ["transform-typescript", ["syntax-decorators", { "legacy": true }]]
+  "plugins": [
+    "transform-typescript",
+    ["syntax-decorators", { "legacy": true }],
+    "syntax-class-properties"
+  ]
 }

packages/babel-plugin-transform-typescript/test/fixtures/class/properties/output.js

@@ -7,4 +7,6 @@ class C {
   e = 3;
   @foo
   g;
+  #h;
+  #i = 10;
 }