Test complete

a.js

@@ -0,0 +1,45 @@
+#!/usr/bin/env node
+const fs = require("fs")
+const babel = require("@babel/core")
+
+const code = `
+export class A {
+  #a: string;
+}
+`
+
+const res = babel.transform(code, {
+  filename: "a.ts",
+  presets: [
+    ["@babel/preset-env", { targets: { node: 14 } }],
+    ["@babel/preset-typescript"],
+  ],
+  plugins: [
+    ({ types: t }) => ({
+      visitor: {
+        ClassDeclaration(path, state) {
+          state.a ??= new WeakSet()
+          if (state.a.has(path.node)) {
+            return
+          }
+          state.a.add(path.node)
+
+          path.parentPath.replaceWithMultiple([
+            t.exportNamedDeclaration(
+              t.variableDeclaration("let", [
+                t.variableDeclarator(path.node.id, {
+                  ...path.node,
+                  type: "ClassExpression",
+                }),
+              ]),
+              [],
+              null
+            ),
+          ])
+        },
+      },
+    }),
+  ],
+})
+
+console.log(res.code)

package.json

@@ -6,11 +6,12 @@
   "scripts": {
     "test": "mocha test/**/*.ts",
     "build": "./scripts/build.js",
-    "postinstall": "mkdir -p lib; cd test/snapshots && ls | sed \"s/.*/'&'/\" | paste -sd '|' | sed -e \"s/^/export type Snapshot = /\" - > ../snapshots.d.ts"
+    "postinstall": "mkdir -p lib; ./scripts/codegen.js test/snapshots > test/snapshots.d.ts"
   },
   "devDependencies": {
     "@babel/core": "^7.14.8",
     "@babel/plugin-transform-modules-commonjs": "^7.14.5",
+    "@babel/preset-env": "^7.14.8",
     "@babel/preset-typescript": "^7.14.5",
     "@babel/register": "^7.14.5",
     "@babel/types": "^7.14.8",

scripts/codegen.js

@@ -0,0 +1,5 @@
+#!/usr/bin/env node
+const fs = require("fs")
+const [arg] = process.argv.slice(2)
+const files = fs.readdirSync(arg).filter(name => name[0] !== ".")
+console.log("export type Snapshot = " + files.map(v => JSON.stringify(v)).join(" | "))

src/index.ts

@@ -50,9 +50,10 @@ export default ({ types: t }: typeof babel): babel.PluginObj<State> => ({
       if (state.visited.has(path.node)) return
       state.visited.add(path.node)
 
-      const modifiers: (t.Expression | t.Statement)[] = []
+      const suffix: (t.Expression | t.Statement)[] = []
       const classDecorators: t.Expression[] = []
       const prefixes: t.Statement[] = []
+      let replace = true
 
       const classID = path.node.id
 
@@ -66,9 +67,14 @@ export default ({ types: t }: typeof babel): babel.PluginObj<State> => ({
 
       for (const child of path.node.body.body) {
         switch (child.type) {
+          case "ClassPrivateMethod":
+          case "ClassPrivateProperty":
+            replace = false
+            break
+
           case "ClassProperty":
             if (!child.decorators) break
-            modifiers.push(
+            suffix.push(
               t.callExpression(state.__decorate(), [
                 t.arrayExpression(child.decorators.map(d => d.expression)),
                 child.static
@@ -119,7 +125,7 @@ export default ({ types: t }: typeof babel): babel.PluginObj<State> => ({
 
                 if (!list.length) break
 
-                modifiers.push(
+                suffix.push(
                   t.callExpression(state.__decorate(), [
                     t.arrayExpression(list),
                     t.memberExpression(classID, t.identifier("prototype")),
@@ -133,16 +139,16 @@ export default ({ types: t }: typeof babel): babel.PluginObj<State> => ({
         }
       }
 
-      if (!classDecorators.length && !modifiers.length && !prefixes.length) return
+      if (!classDecorators.length && !suffix.length && !prefixes.length) return
+      let replaceWith: t.Statement | undefined
 
-      const replacees: t.Statement[] = prefixes.slice()
       if (classDecorators.length) {
-        replacees.push(
-          t.variableDeclaration("let", [
+        if (replace) {
+          replaceWith = t.variableDeclaration("let", [
             t.variableDeclarator(classID, { ...path.node, type: "ClassExpression" }),
           ])
-        )
-        modifiers.push(
+        }
+        suffix.push(
           t.assignmentExpression(
             "=",
             classID,
@@ -154,27 +160,35 @@ export default ({ types: t }: typeof babel): babel.PluginObj<State> => ({
         )
 
         if (isNamedExport) {
-          modifiers.push(
+          suffix.push(
             t.exportNamedDeclaration(undefined, [t.exportSpecifier(classID, classID)])
           )
         } else if (isDefaultExport) {
-          modifiers.push(t.exportDefaultDeclaration(classID))
+          suffix.push(t.exportDefaultDeclaration(classID))
         }
-      } else {
+      } else if (replace) {
         let node: t.Statement = path.node
         if (isNamedExport) {
           node = t.exportNamedDeclaration(node, [], null)
         } else if (isDefaultExport) {
           node = t.exportDefaultDeclaration(node)
         }
-        replacees.push(node)
+        replaceWith = node
       }
 
-      replacees.push(
-        ...modifiers.map(e => (t.isStatement(e) ? e : t.expressionStatement(e)))
-      )
-      const replacementTarget = isNamedExport || isDefaultExport ? path.parentPath : path
-      replacementTarget.replaceWithMultiple(replacees)
+      const pathInContext = isNamedExport || isDefaultExport ? path.parentPath : path
+      if (prefixes.length) {
+        pathInContext.insertBefore(prefixes)
+      }
+      if (suffix.length) {
+        const nodes = suffix.map(s => (t.isStatement(s) ? s : t.expressionStatement(s)))
+        if (replace) {
+          const [newPath] = pathInContext.replaceWith(replaceWith!)
+          newPath.insertAfter(nodes)
+        } else {
+          pathInContext.insertAfter(nodes)
+        }
+      }
     },
   },
 })

test/index.ts

@@ -1,4 +1,4 @@
-import { readFileSync } from "fs"
+import { readFileSync, existsSync } from "fs"
 import { describe, it } from "mocha"
 import { resolve } from "path"
 import { expect } from "chai"
@@ -14,13 +14,20 @@ const equal = (name: Snapshot) => {
   const folder = resolve(__dirname, "snapshots", name)
   const actual = readFileSync(resolve(folder, "input.txt"), "utf-8")
   const expected = readFileSync(resolve(folder, "output.txt"), "utf-8")
+  const babelrc: babel.TransformOptions = existsSync(resolve(folder, ".babelrc"))
+    ? JSON.parse(readFileSync(resolve(folder, ".babelrc"), "utf-8"))
+    : {}
+
   const transformed = transform(actual, {
     parserOpts: {
+      ...babelrc.parserOpts,
       plugins: ["decorators-legacy", "typescript"],
     },
     babelrc: false,
     configFile: false,
+    presets: babelrc.presets,
     plugins: [
+      ...(babelrc.plugins ?? []),
       plugin,
       {
         visitor: {
@@ -52,11 +59,15 @@ describe("tsc-decorator", () => {
     equal("computedProperties")
   })
 
-  it("works with class/consrtuctor decorators", () => {
+  it("works with class/constructor decorators", () => {
     equal("constructor")
   })
 
   it("does not interfere with export declarations", () => {
     equal("exports")
   })
+
+  it("works with private properties", () => {
+    equal("privateProperties")
+  })
 })

test/snapshots/privateProperties/.babelrc

@@ -0,0 +1,3 @@
+{
+  "presets": [["@babel/preset-env", { "targets": { "node": 14 } }]]
+}

test/snapshots/privateProperties/input.txt

@@ -0,0 +1,4 @@
+@Service()
+export class B {
+  #remote: Service
+}

test/snapshots/privateProperties/output.txt

@@ -0,0 +1,22 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", {
+  value: true,
+});
+
+exports.B = exports.B = void 0;
+
+var _tslib = require("tslib");
+var _remote = /*#__PURE__*/ new WeakMap();
+
+exports.B = exports.B = B = (0, _tslib.__decorate)([Service()], B);
+
+class B {
+  constructor() {
+    _remote.set(this, {
+      writable: true,
+      value: void 0,
+    });
+  }
+}
+
+exports.B = exports.B = B;