repro for microsoft/TypeScript#5110

Author: basarat

bugs/643/build/a.js

@@ -0,0 +1,7 @@
+var b_1 = require('./b');
+class A {
+    constructor() {
+        this.b = new b_1.B();
+    }
+}
+exports.A = A;

bugs/643/build/b.js

@@ -0,0 +1,5 @@
+class B {
+    constructor() {
+    }
+}
+exports.B = B;

bugs/643/src/a.ts

@@ -0,0 +1,8 @@
+import { B }from './b'
+
+export class A {
+  b:B;
+  constructor(){
+    this.b = new B();
+  }
+}

bugs/643/src/b.ts

@@ -0,0 +1,3 @@
+export class B {
+  constructor(){}
+}

bugs/643/tsconfig.json

@@ -0,0 +1,22 @@
+{
+    "transpiler": "typescript",
+    "compileOnSave": true,
+    "compilerOptions": {
+        "target": "es6",
+        "declaration": false,
+        "noImplicitAny": false,
+        "removeComments": true,
+        "emitDecoratorMetadata": true,
+        "experimentalDecorators": true,
+        "noLib": false,
+        "outDir": "build"
+    },
+    "filesGlob": [
+        "./src/*.ts"
+    ],
+    "files": [
+        "./src/a.ts",
+        "./src/b.ts"
+    ],
+    "exclude": []
+}