diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 58f0ec42d0c90..cff964361a6f2 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -11384,9 +11384,16 @@ namespace ts {
             // serialize the type metadata.
             if (node && node.kind === SyntaxKind.TypeReference) {
                 let root = getFirstIdentifier((<TypeReferenceNode>node).typeName);
-                let rootSymbol = resolveName(root, root.text, SymbolFlags.Value, /*nameNotFoundMessage*/ undefined, /*nameArg*/ undefined);
-                if (rootSymbol && rootSymbol.flags & SymbolFlags.Alias && !isInTypeQuery(node) && !isConstEnumOrConstEnumOnlyModule(resolveAlias(rootSymbol))) {
-                    markAliasSymbolAsReferenced(rootSymbol);
+                let meaning = root.parent.kind === SyntaxKind.TypeReference ? SymbolFlags.Type : SymbolFlags.Namespace;
+                // Resolve type so we know which symbol is referenced
+                let rootSymbol = resolveName(root, root.text, meaning | SymbolFlags.Alias, /*nameNotFoundMessage*/ undefined, /*nameArg*/ undefined);
+                // Resolved symbol is alias
+                if (rootSymbol && rootSymbol.flags & SymbolFlags.Alias) {
+                    let aliasTarget = resolveAlias(rootSymbol);
+                    // If alias has value symbol - mark alias as referenced
+                    if (aliasTarget.flags & SymbolFlags.Value && !isConstEnumOrConstEnumOnlyModule(resolveAlias(rootSymbol))) {
+                        markAliasSymbolAsReferenced(rootSymbol);
+                    }
                 }
             }
         }
@@ -14402,6 +14409,10 @@ namespace ts {
 
             // Resolve the symbol as a type so that we can provide a more useful hint for the type serializer.
             let typeSymbol = resolveEntityName(typeName, SymbolFlags.Type, /*ignoreErrors*/ true);
+            // We might not be able to resolve type symbol so use unknown type in that case (eg error case)
+            if (!typeSymbol) {
+                return TypeReferenceSerializationKind.ObjectType; 
+            }
             let type = getDeclaredTypeOfSymbol(typeSymbol);
             if (type === unknownType) {
                 return TypeReferenceSerializationKind.Unknown;
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index a633da8159722..abcc32c1198f2 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -1552,6 +1552,9 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                 else if (isNameOfNestedRedeclaration(node)) {
                     write(getGeneratedNameForNode(node));
                 }
+                else if (nodeIsSynthesized(node)) {
+                    write(node.text);
+                }
                 else {
                     writeTextOfNode(currentSourceFile, node);
                 }
diff --git a/tests/baselines/reference/decoratorMetadata.js b/tests/baselines/reference/decoratorMetadata.js
index ea776d09910c9..5c2ce580507dd 100644
--- a/tests/baselines/reference/decoratorMetadata.js
+++ b/tests/baselines/reference/decoratorMetadata.js
@@ -34,6 +34,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
 var __metadata = (this && this.__metadata) || function (k, v) {
     if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
 };
+var service_1 = require("./service");
 var MyComponent = (function () {
     function MyComponent(Service) {
         this.Service = Service;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.js b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.js
new file mode 100644
index 0000000000000..392506e53683f
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.js
@@ -0,0 +1,51 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision.ts] ////
+
+//// [db.ts]
+export class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import {db} from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db;
+
+    constructor(db: db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+//// [db.js]
+var db = (function () {
+    function db() {
+    }
+    db.prototype.doSomething = function () {
+    };
+    return db;
+})();
+exports.db = db;
+//// [service.js]
+var db_1 = require('./db');
+function someDecorator(target) {
+    return target;
+}
+var MyClass = (function () {
+    function MyClass(db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+    MyClass = __decorate([
+        someDecorator, 
+        __metadata('design:paramtypes', [db_1.db])
+    ], MyClass);
+    return MyClass;
+})();
+exports.MyClass = MyClass;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.symbols b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.symbols
new file mode 100644
index 0000000000000..c967239df99ea
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.symbols
@@ -0,0 +1,51 @@
+=== tests/cases/compiler/db.ts ===
+export class db {
+>db : Symbol(db, Decl(db.ts, 0, 0))
+
+    public doSomething() {
+>doSomething : Symbol(doSomething, Decl(db.ts, 0, 17))
+    }
+}
+
+=== tests/cases/compiler/service.ts ===
+import {db} from './db';
+>db : Symbol(db, Decl(service.ts, 0, 8))
+
+function someDecorator(target) {
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 24))
+>target : Symbol(target, Decl(service.ts, 1, 23))
+
+    return target;
+>target : Symbol(target, Decl(service.ts, 1, 23))
+}
+@someDecorator
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 24))
+
+class MyClass {
+>MyClass : Symbol(MyClass, Decl(service.ts, 3, 1))
+
+    db: db;
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 0, 8))
+
+    constructor(db: db) {
+>db : Symbol(db, Decl(service.ts, 8, 16))
+>db : Symbol(db, Decl(service.ts, 0, 8))
+
+        this.db = db;
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 8, 16))
+
+        this.db.doSomething();
+>this.db.doSomething : Symbol(db.doSomething, Decl(db.ts, 0, 17))
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>doSomething : Symbol(db.doSomething, Decl(db.ts, 0, 17))
+    }
+}
+export {MyClass};
+>MyClass : Symbol(MyClass, Decl(service.ts, 13, 8))
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.types b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.types
new file mode 100644
index 0000000000000..60cf7f10cea19
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision.types
@@ -0,0 +1,53 @@
+=== tests/cases/compiler/db.ts ===
+export class db {
+>db : db
+
+    public doSomething() {
+>doSomething : () => void
+    }
+}
+
+=== tests/cases/compiler/service.ts ===
+import {db} from './db';
+>db : typeof db
+
+function someDecorator(target) {
+>someDecorator : (target: any) => any
+>target : any
+
+    return target;
+>target : any
+}
+@someDecorator
+>someDecorator : (target: any) => any
+
+class MyClass {
+>MyClass : MyClass
+
+    db: db;
+>db : db
+>db : db
+
+    constructor(db: db) {
+>db : db
+>db : db
+
+        this.db = db;
+>this.db = db : db
+>this.db : db
+>this : MyClass
+>db : db
+>db : db
+
+        this.db.doSomething();
+>this.db.doSomething() : void
+>this.db.doSomething : () => void
+>this.db : db
+>this : MyClass
+>db : db
+>doSomething : () => void
+    }
+}
+export {MyClass};
+>MyClass : typeof MyClass
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.js b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.js
new file mode 100644
index 0000000000000..da011acf1105c
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.js
@@ -0,0 +1,51 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision2.ts] ////
+
+//// [db.ts]
+export class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import {db as Database} from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: Database;
+
+    constructor(db: Database) { // no collision
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+//// [db.js]
+var db = (function () {
+    function db() {
+    }
+    db.prototype.doSomething = function () {
+    };
+    return db;
+})();
+exports.db = db;
+//// [service.js]
+var db_1 = require('./db');
+function someDecorator(target) {
+    return target;
+}
+var MyClass = (function () {
+    function MyClass(db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+    MyClass = __decorate([
+        someDecorator, 
+        __metadata('design:paramtypes', [db_1.db])
+    ], MyClass);
+    return MyClass;
+})();
+exports.MyClass = MyClass;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.symbols b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.symbols
new file mode 100644
index 0000000000000..d79b05f68f680
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.symbols
@@ -0,0 +1,52 @@
+=== tests/cases/compiler/db.ts ===
+export class db {
+>db : Symbol(db, Decl(db.ts, 0, 0))
+
+    public doSomething() {
+>doSomething : Symbol(doSomething, Decl(db.ts, 0, 17))
+    }
+}
+
+=== tests/cases/compiler/service.ts ===
+import {db as Database} from './db';
+>db : Symbol(Database, Decl(service.ts, 0, 8))
+>Database : Symbol(Database, Decl(service.ts, 0, 8))
+
+function someDecorator(target) {
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 36))
+>target : Symbol(target, Decl(service.ts, 1, 23))
+
+    return target;
+>target : Symbol(target, Decl(service.ts, 1, 23))
+}
+@someDecorator
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 36))
+
+class MyClass {
+>MyClass : Symbol(MyClass, Decl(service.ts, 3, 1))
+
+    db: Database;
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>Database : Symbol(Database, Decl(service.ts, 0, 8))
+
+    constructor(db: Database) { // no collision
+>db : Symbol(db, Decl(service.ts, 8, 16))
+>Database : Symbol(Database, Decl(service.ts, 0, 8))
+
+        this.db = db;
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 8, 16))
+
+        this.db.doSomething();
+>this.db.doSomething : Symbol(Database.doSomething, Decl(db.ts, 0, 17))
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>doSomething : Symbol(Database.doSomething, Decl(db.ts, 0, 17))
+    }
+}
+export {MyClass};
+>MyClass : Symbol(MyClass, Decl(service.ts, 13, 8))
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.types b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.types
new file mode 100644
index 0000000000000..73005b4673f9b
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision2.types
@@ -0,0 +1,54 @@
+=== tests/cases/compiler/db.ts ===
+export class db {
+>db : db
+
+    public doSomething() {
+>doSomething : () => void
+    }
+}
+
+=== tests/cases/compiler/service.ts ===
+import {db as Database} from './db';
+>db : typeof Database
+>Database : typeof Database
+
+function someDecorator(target) {
+>someDecorator : (target: any) => any
+>target : any
+
+    return target;
+>target : any
+}
+@someDecorator
+>someDecorator : (target: any) => any
+
+class MyClass {
+>MyClass : MyClass
+
+    db: Database;
+>db : Database
+>Database : Database
+
+    constructor(db: Database) { // no collision
+>db : Database
+>Database : Database
+
+        this.db = db;
+>this.db = db : Database
+>this.db : Database
+>this : MyClass
+>db : Database
+>db : Database
+
+        this.db.doSomething();
+>this.db.doSomething() : void
+>this.db.doSomething : () => void
+>this.db : Database
+>this : MyClass
+>db : Database
+>doSomething : () => void
+    }
+}
+export {MyClass};
+>MyClass : typeof MyClass
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.js b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.js
new file mode 100644
index 0000000000000..b219bba4102f0
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.js
@@ -0,0 +1,51 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision3.ts] ////
+
+//// [db.ts]
+export class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import db = require('./db');
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db.db;
+
+    constructor(db: db.db) { // collision with namespace of external module db
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+//// [db.js]
+var db = (function () {
+    function db() {
+    }
+    db.prototype.doSomething = function () {
+    };
+    return db;
+})();
+exports.db = db;
+//// [service.js]
+var db = require('./db');
+function someDecorator(target) {
+    return target;
+}
+var MyClass = (function () {
+    function MyClass(db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+    MyClass = __decorate([
+        someDecorator, 
+        __metadata('design:paramtypes', [db.db])
+    ], MyClass);
+    return MyClass;
+})();
+exports.MyClass = MyClass;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.symbols b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.symbols
new file mode 100644
index 0000000000000..b34468c7bd54f
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.symbols
@@ -0,0 +1,53 @@
+=== tests/cases/compiler/service.ts ===
+import db = require('./db');
+>db : Symbol(db, Decl(service.ts, 0, 0))
+
+function someDecorator(target) {
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 28))
+>target : Symbol(target, Decl(service.ts, 1, 23))
+
+    return target;
+>target : Symbol(target, Decl(service.ts, 1, 23))
+}
+@someDecorator
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 28))
+
+class MyClass {
+>MyClass : Symbol(MyClass, Decl(service.ts, 3, 1))
+
+    db: db.db;
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 0, 0))
+>db : Symbol(db.db, Decl(db.ts, 0, 0))
+
+    constructor(db: db.db) { // collision with namespace of external module db
+>db : Symbol(db, Decl(service.ts, 8, 16))
+>db : Symbol(db, Decl(service.ts, 0, 0))
+>db : Symbol(db.db, Decl(db.ts, 0, 0))
+
+        this.db = db;
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 8, 16))
+
+        this.db.doSomething();
+>this.db.doSomething : Symbol(db.db.doSomething, Decl(db.ts, 0, 17))
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>doSomething : Symbol(db.db.doSomething, Decl(db.ts, 0, 17))
+    }
+}
+export {MyClass};
+>MyClass : Symbol(MyClass, Decl(service.ts, 13, 8))
+
+=== tests/cases/compiler/db.ts ===
+export class db {
+>db : Symbol(db, Decl(db.ts, 0, 0))
+
+    public doSomething() {
+>doSomething : Symbol(doSomething, Decl(db.ts, 0, 17))
+    }
+}
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.types b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.types
new file mode 100644
index 0000000000000..0eea3e13b660a
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision3.types
@@ -0,0 +1,55 @@
+=== tests/cases/compiler/service.ts ===
+import db = require('./db');
+>db : typeof db
+
+function someDecorator(target) {
+>someDecorator : (target: any) => any
+>target : any
+
+    return target;
+>target : any
+}
+@someDecorator
+>someDecorator : (target: any) => any
+
+class MyClass {
+>MyClass : MyClass
+
+    db: db.db;
+>db : db.db
+>db : any
+>db : db.db
+
+    constructor(db: db.db) { // collision with namespace of external module db
+>db : db.db
+>db : any
+>db : db.db
+
+        this.db = db;
+>this.db = db : db.db
+>this.db : db.db
+>this : MyClass
+>db : db.db
+>db : db.db
+
+        this.db.doSomething();
+>this.db.doSomething() : void
+>this.db.doSomething : () => void
+>this.db : db.db
+>this : MyClass
+>db : db.db
+>doSomething : () => void
+    }
+}
+export {MyClass};
+>MyClass : typeof MyClass
+
+=== tests/cases/compiler/db.ts ===
+export class db {
+>db : db
+
+    public doSomething() {
+>doSomething : () => void
+    }
+}
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision4.errors.txt b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision4.errors.txt
new file mode 100644
index 0000000000000..611a080481285
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision4.errors.txt
@@ -0,0 +1,27 @@
+tests/cases/compiler/service.ts(1,8): error TS1192: Module '"tests/cases/compiler/db"' has no default export.
+
+
+==== tests/cases/compiler/db.ts (0 errors) ====
+    export class db {
+        public doSomething() {
+        }
+    }
+    
+==== tests/cases/compiler/service.ts (1 errors) ====
+    import db from './db'; // error no default export
+           ~~
+!!! error TS1192: Module '"tests/cases/compiler/db"' has no default export.
+    function someDecorator(target) {
+        return target;
+    }
+    @someDecorator
+    class MyClass {
+        db: db.db;
+    
+        constructor(db: db.db) {
+            this.db = db;
+            this.db.doSomething();
+        }
+    }
+    export {MyClass};
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision4.js b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision4.js
new file mode 100644
index 0000000000000..d0d201e62b5f2
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision4.js
@@ -0,0 +1,51 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision4.ts] ////
+
+//// [db.ts]
+export class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import db from './db'; // error no default export
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db.db;
+
+    constructor(db: db.db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+//// [db.js]
+var db = (function () {
+    function db() {
+    }
+    db.prototype.doSomething = function () {
+    };
+    return db;
+})();
+exports.db = db;
+//// [service.js]
+var db_1 = require('./db'); // error no default export
+function someDecorator(target) {
+    return target;
+}
+var MyClass = (function () {
+    function MyClass(db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+    MyClass = __decorate([
+        someDecorator, 
+        __metadata('design:paramtypes', [Object])
+    ], MyClass);
+    return MyClass;
+})();
+exports.MyClass = MyClass;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.js b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.js
new file mode 100644
index 0000000000000..a25995153382b
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.js
@@ -0,0 +1,52 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision5.ts] ////
+
+//// [db.ts]
+export default class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import db from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db;
+
+    constructor(db: db) { // collision
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+//// [db.js]
+var db = (function () {
+    function db() {
+    }
+    db.prototype.doSomething = function () {
+    };
+    return db;
+})();
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = db;
+//// [service.js]
+var db_1 = require('./db');
+function someDecorator(target) {
+    return target;
+}
+var MyClass = (function () {
+    function MyClass(db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+    MyClass = __decorate([
+        someDecorator, 
+        __metadata('design:paramtypes', [db_1.default])
+    ], MyClass);
+    return MyClass;
+})();
+exports.MyClass = MyClass;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.symbols b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.symbols
new file mode 100644
index 0000000000000..6047d7f288216
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.symbols
@@ -0,0 +1,51 @@
+=== tests/cases/compiler/db.ts ===
+export default class db {
+>db : Symbol(db, Decl(db.ts, 0, 0))
+
+    public doSomething() {
+>doSomething : Symbol(doSomething, Decl(db.ts, 0, 25))
+    }
+}
+
+=== tests/cases/compiler/service.ts ===
+import db from './db';
+>db : Symbol(db, Decl(service.ts, 0, 6))
+
+function someDecorator(target) {
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 22))
+>target : Symbol(target, Decl(service.ts, 1, 23))
+
+    return target;
+>target : Symbol(target, Decl(service.ts, 1, 23))
+}
+@someDecorator
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 22))
+
+class MyClass {
+>MyClass : Symbol(MyClass, Decl(service.ts, 3, 1))
+
+    db: db;
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 0, 6))
+
+    constructor(db: db) { // collision
+>db : Symbol(db, Decl(service.ts, 8, 16))
+>db : Symbol(db, Decl(service.ts, 0, 6))
+
+        this.db = db;
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 8, 16))
+
+        this.db.doSomething();
+>this.db.doSomething : Symbol(db.doSomething, Decl(db.ts, 0, 25))
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>doSomething : Symbol(db.doSomething, Decl(db.ts, 0, 25))
+    }
+}
+export {MyClass};
+>MyClass : Symbol(MyClass, Decl(service.ts, 13, 8))
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.types b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.types
new file mode 100644
index 0000000000000..0fbc48db15718
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision5.types
@@ -0,0 +1,53 @@
+=== tests/cases/compiler/db.ts ===
+export default class db {
+>db : db
+
+    public doSomething() {
+>doSomething : () => void
+    }
+}
+
+=== tests/cases/compiler/service.ts ===
+import db from './db';
+>db : typeof db
+
+function someDecorator(target) {
+>someDecorator : (target: any) => any
+>target : any
+
+    return target;
+>target : any
+}
+@someDecorator
+>someDecorator : (target: any) => any
+
+class MyClass {
+>MyClass : MyClass
+
+    db: db;
+>db : db
+>db : db
+
+    constructor(db: db) { // collision
+>db : db
+>db : db
+
+        this.db = db;
+>this.db = db : db
+>this.db : db
+>this : MyClass
+>db : db
+>db : db
+
+        this.db.doSomething();
+>this.db.doSomething() : void
+>this.db.doSomething : () => void
+>this.db : db
+>this : MyClass
+>db : db
+>doSomething : () => void
+    }
+}
+export {MyClass};
+>MyClass : typeof MyClass
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.js b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.js
new file mode 100644
index 0000000000000..917cdc7036f0e
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.js
@@ -0,0 +1,52 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision6.ts] ////
+
+//// [db.ts]
+export default class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import database from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: database;
+
+    constructor(db: database) { // no collision
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+//// [db.js]
+var db = (function () {
+    function db() {
+    }
+    db.prototype.doSomething = function () {
+    };
+    return db;
+})();
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = db;
+//// [service.js]
+var db_1 = require('./db');
+function someDecorator(target) {
+    return target;
+}
+var MyClass = (function () {
+    function MyClass(db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+    MyClass = __decorate([
+        someDecorator, 
+        __metadata('design:paramtypes', [db_1.default])
+    ], MyClass);
+    return MyClass;
+})();
+exports.MyClass = MyClass;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.symbols b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.symbols
new file mode 100644
index 0000000000000..27f807503bfd7
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.symbols
@@ -0,0 +1,51 @@
+=== tests/cases/compiler/db.ts ===
+export default class db {
+>db : Symbol(db, Decl(db.ts, 0, 0))
+
+    public doSomething() {
+>doSomething : Symbol(doSomething, Decl(db.ts, 0, 25))
+    }
+}
+
+=== tests/cases/compiler/service.ts ===
+import database from './db';
+>database : Symbol(database, Decl(service.ts, 0, 6))
+
+function someDecorator(target) {
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 28))
+>target : Symbol(target, Decl(service.ts, 1, 23))
+
+    return target;
+>target : Symbol(target, Decl(service.ts, 1, 23))
+}
+@someDecorator
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 28))
+
+class MyClass {
+>MyClass : Symbol(MyClass, Decl(service.ts, 3, 1))
+
+    db: database;
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>database : Symbol(database, Decl(service.ts, 0, 6))
+
+    constructor(db: database) { // no collision
+>db : Symbol(db, Decl(service.ts, 8, 16))
+>database : Symbol(database, Decl(service.ts, 0, 6))
+
+        this.db = db;
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 8, 16))
+
+        this.db.doSomething();
+>this.db.doSomething : Symbol(database.doSomething, Decl(db.ts, 0, 25))
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>doSomething : Symbol(database.doSomething, Decl(db.ts, 0, 25))
+    }
+}
+export {MyClass};
+>MyClass : Symbol(MyClass, Decl(service.ts, 13, 8))
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.types b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.types
new file mode 100644
index 0000000000000..e3a68882dfb9d
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision6.types
@@ -0,0 +1,53 @@
+=== tests/cases/compiler/db.ts ===
+export default class db {
+>db : db
+
+    public doSomething() {
+>doSomething : () => void
+    }
+}
+
+=== tests/cases/compiler/service.ts ===
+import database from './db';
+>database : typeof database
+
+function someDecorator(target) {
+>someDecorator : (target: any) => any
+>target : any
+
+    return target;
+>target : any
+}
+@someDecorator
+>someDecorator : (target: any) => any
+
+class MyClass {
+>MyClass : MyClass
+
+    db: database;
+>db : database
+>database : database
+
+    constructor(db: database) { // no collision
+>db : database
+>database : database
+
+        this.db = db;
+>this.db = db : database
+>this.db : database
+>this : MyClass
+>db : database
+>db : database
+
+        this.db.doSomething();
+>this.db.doSomething() : void
+>this.db.doSomething : () => void
+>this.db : database
+>this : MyClass
+>db : database
+>doSomething : () => void
+    }
+}
+export {MyClass};
+>MyClass : typeof MyClass
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision7.errors.txt b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision7.errors.txt
new file mode 100644
index 0000000000000..d4b714f1d4ae2
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision7.errors.txt
@@ -0,0 +1,30 @@
+tests/cases/compiler/service.ts(7,9): error TS2503: Cannot find namespace 'db'.
+tests/cases/compiler/service.ts(9,21): error TS2503: Cannot find namespace 'db'.
+
+
+==== tests/cases/compiler/db.ts (0 errors) ====
+    export default class db {
+        public doSomething() {
+        }
+    }
+    
+==== tests/cases/compiler/service.ts (2 errors) ====
+    import db from './db';
+    function someDecorator(target) {
+        return target;
+    }
+    @someDecorator
+    class MyClass {
+        db: db.db; //error
+            ~~
+!!! error TS2503: Cannot find namespace 'db'.
+    
+        constructor(db: db.db) { // error
+                        ~~
+!!! error TS2503: Cannot find namespace 'db'.
+            this.db = db;
+            this.db.doSomething();
+        }
+    }
+    export {MyClass};
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision7.js b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision7.js
new file mode 100644
index 0000000000000..1dd93b12915f5
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision7.js
@@ -0,0 +1,52 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision7.ts] ////
+
+//// [db.ts]
+export default class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import db from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db.db; //error
+
+    constructor(db: db.db) { // error
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+//// [db.js]
+var db = (function () {
+    function db() {
+    }
+    db.prototype.doSomething = function () {
+    };
+    return db;
+})();
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.default = db;
+//// [service.js]
+var db_1 = require('./db');
+function someDecorator(target) {
+    return target;
+}
+var MyClass = (function () {
+    function MyClass(db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+    MyClass = __decorate([
+        someDecorator, 
+        __metadata('design:paramtypes', [Object])
+    ], MyClass);
+    return MyClass;
+})();
+exports.MyClass = MyClass;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.js b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.js
new file mode 100644
index 0000000000000..0aee9e471dd43
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.js
@@ -0,0 +1,51 @@
+//// [tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision8.ts] ////
+
+//// [db.ts]
+export class db {
+    public doSomething() {
+    }
+}
+
+//// [service.ts]
+import database = require('./db');
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: database.db;
+
+    constructor(db: database.db) { // no collision
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
+
+
+//// [db.js]
+var db = (function () {
+    function db() {
+    }
+    db.prototype.doSomething = function () {
+    };
+    return db;
+})();
+exports.db = db;
+//// [service.js]
+var database = require('./db');
+function someDecorator(target) {
+    return target;
+}
+var MyClass = (function () {
+    function MyClass(db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+    MyClass = __decorate([
+        someDecorator, 
+        __metadata('design:paramtypes', [database.db])
+    ], MyClass);
+    return MyClass;
+})();
+exports.MyClass = MyClass;
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.symbols b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.symbols
new file mode 100644
index 0000000000000..1b73ea2e9a343
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.symbols
@@ -0,0 +1,53 @@
+=== tests/cases/compiler/service.ts ===
+import database = require('./db');
+>database : Symbol(database, Decl(service.ts, 0, 0))
+
+function someDecorator(target) {
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 34))
+>target : Symbol(target, Decl(service.ts, 1, 23))
+
+    return target;
+>target : Symbol(target, Decl(service.ts, 1, 23))
+}
+@someDecorator
+>someDecorator : Symbol(someDecorator, Decl(service.ts, 0, 34))
+
+class MyClass {
+>MyClass : Symbol(MyClass, Decl(service.ts, 3, 1))
+
+    db: database.db;
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>database : Symbol(database, Decl(service.ts, 0, 0))
+>db : Symbol(database.db, Decl(db.ts, 0, 0))
+
+    constructor(db: database.db) { // no collision
+>db : Symbol(db, Decl(service.ts, 8, 16))
+>database : Symbol(database, Decl(service.ts, 0, 0))
+>db : Symbol(database.db, Decl(db.ts, 0, 0))
+
+        this.db = db;
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>db : Symbol(db, Decl(service.ts, 8, 16))
+
+        this.db.doSomething();
+>this.db.doSomething : Symbol(database.db.doSomething, Decl(db.ts, 0, 17))
+>this.db : Symbol(db, Decl(service.ts, 5, 15))
+>this : Symbol(MyClass, Decl(service.ts, 3, 1))
+>db : Symbol(db, Decl(service.ts, 5, 15))
+>doSomething : Symbol(database.db.doSomething, Decl(db.ts, 0, 17))
+    }
+}
+export {MyClass};
+>MyClass : Symbol(MyClass, Decl(service.ts, 13, 8))
+
+=== tests/cases/compiler/db.ts ===
+export class db {
+>db : Symbol(db, Decl(db.ts, 0, 0))
+
+    public doSomething() {
+>doSomething : Symbol(doSomething, Decl(db.ts, 0, 17))
+    }
+}
+
diff --git a/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.types b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.types
new file mode 100644
index 0000000000000..faaab05688541
--- /dev/null
+++ b/tests/baselines/reference/decoratorMetadataWithImportDeclarationNameCollision8.types
@@ -0,0 +1,55 @@
+=== tests/cases/compiler/service.ts ===
+import database = require('./db');
+>database : typeof database
+
+function someDecorator(target) {
+>someDecorator : (target: any) => any
+>target : any
+
+    return target;
+>target : any
+}
+@someDecorator
+>someDecorator : (target: any) => any
+
+class MyClass {
+>MyClass : MyClass
+
+    db: database.db;
+>db : database.db
+>database : any
+>db : database.db
+
+    constructor(db: database.db) { // no collision
+>db : database.db
+>database : any
+>db : database.db
+
+        this.db = db;
+>this.db = db : database.db
+>this.db : database.db
+>this : MyClass
+>db : database.db
+>db : database.db
+
+        this.db.doSomething();
+>this.db.doSomething() : void
+>this.db.doSomething : () => void
+>this.db : database.db
+>this : MyClass
+>db : database.db
+>doSomething : () => void
+    }
+}
+export {MyClass};
+>MyClass : typeof MyClass
+
+=== tests/cases/compiler/db.ts ===
+export class db {
+>db : db
+
+    public doSomething() {
+>doSomething : () => void
+    }
+}
+
diff --git a/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision.ts b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision.ts
new file mode 100644
index 0000000000000..8d198e44752f5
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision.ts
@@ -0,0 +1,26 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+// @filename: db.ts
+export class db {
+    public doSomething() {
+    }
+}
+
+// @filename: service.ts
+import {db} from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db;
+
+    constructor(db: db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
diff --git a/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision2.ts b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision2.ts
new file mode 100644
index 0000000000000..ac097dd3ba452
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision2.ts
@@ -0,0 +1,26 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+// @filename: db.ts
+export class db {
+    public doSomething() {
+    }
+}
+
+// @filename: service.ts
+import {db as Database} from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: Database;
+
+    constructor(db: Database) { // no collision
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
diff --git a/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision3.ts b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision3.ts
new file mode 100644
index 0000000000000..e15570cb5baae
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision3.ts
@@ -0,0 +1,26 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+// @filename: db.ts
+export class db {
+    public doSomething() {
+    }
+}
+
+// @filename: service.ts
+import db = require('./db');
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db.db;
+
+    constructor(db: db.db) { // collision with namespace of external module db
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
diff --git a/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision4.ts b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision4.ts
new file mode 100644
index 0000000000000..d04d1300531da
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision4.ts
@@ -0,0 +1,26 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+// @filename: db.ts
+export class db {
+    public doSomething() {
+    }
+}
+
+// @filename: service.ts
+import db from './db'; // error no default export
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db.db;
+
+    constructor(db: db.db) {
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
diff --git a/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision5.ts b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision5.ts
new file mode 100644
index 0000000000000..24934963b3e12
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision5.ts
@@ -0,0 +1,26 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+// @filename: db.ts
+export default class db {
+    public doSomething() {
+    }
+}
+
+// @filename: service.ts
+import db from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db;
+
+    constructor(db: db) { // collision
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
diff --git a/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision6.ts b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision6.ts
new file mode 100644
index 0000000000000..2043279c4aaf2
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision6.ts
@@ -0,0 +1,26 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+// @filename: db.ts
+export default class db {
+    public doSomething() {
+    }
+}
+
+// @filename: service.ts
+import database from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: database;
+
+    constructor(db: database) { // no collision
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
diff --git a/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision7.ts b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision7.ts
new file mode 100644
index 0000000000000..bbedf61c6dfc5
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision7.ts
@@ -0,0 +1,26 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+// @filename: db.ts
+export default class db {
+    public doSomething() {
+    }
+}
+
+// @filename: service.ts
+import db from './db';
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: db.db; //error
+
+    constructor(db: db.db) { // error
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
diff --git a/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision8.ts b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision8.ts
new file mode 100644
index 0000000000000..e3318d813a87b
--- /dev/null
+++ b/tests/cases/compiler/decoratorMetadataWithImportDeclarationNameCollision8.ts
@@ -0,0 +1,26 @@
+// @noemithelpers: true
+// @experimentaldecorators: true
+// @emitdecoratormetadata: true
+// @target: es5
+// @module: commonjs
+// @filename: db.ts
+export class db {
+    public doSomething() {
+    }
+}
+
+// @filename: service.ts
+import database = require('./db');
+function someDecorator(target) {
+    return target;
+}
+@someDecorator
+class MyClass {
+    db: database.db;
+
+    constructor(db: database.db) { // no collision
+        this.db = db;
+        this.db.doSomething();
+    }
+}
+export {MyClass};
diff --git a/tests/cases/unittests/transpile.ts b/tests/cases/unittests/transpile.ts
index c222e2ebb8278..0b87910d26e49 100644
--- a/tests/cases/unittests/transpile.ts
+++ b/tests/cases/unittests/transpile.ts
@@ -220,6 +220,55 @@ var x = 0;`,
                     expectedOutput: output
                 });
         });
+        
+        it("Transpile with emit decorators and emit metadata", () => {
+            let input = 
+                `import {db} from './db';\n` +
+                `function someDecorator(target) {\n` +
+                `    return target;\n` +
+                `} \n` +
+                `@someDecorator\n` +
+                `class MyClass {\n` +
+                `    db: db;\n` +
+                `    constructor(db: db) {\n` +
+                `        this.db = db;\n` +
+                `        this.db.doSomething(); \n` +
+                `    }\n` +
+                `}\n` +
+                `export {MyClass}; \n`
+            let output =
+                `var db_1 = require(\'./db\');\n` + 
+                `function someDecorator(target) {\n` +
+                `    return target;\n` +
+                `}\n` + 
+                `var MyClass = (function () {\n` + 
+                `    function MyClass(db) {\n` + 
+                `        this.db = db;\n` + 
+                `        this.db.doSomething();\n` + 
+                `    }\n` + 
+                `    MyClass = __decorate([\n` + 
+                `        someDecorator, \n` + 
+                `        __metadata(\'design:paramtypes\', [(typeof (_a = typeof db_1.db !== \'undefined\' && db_1.db) === \'function\' && _a) || Object])\n` + 
+                `    ], MyClass);\n` + 
+                `    return MyClass;\n` + 
+                `    var _a;\n` + 
+                `})();\n` + 
+                `exports.MyClass = MyClass;\n`;
 
+            test(input, 
+                { 
+                    options: {
+                        compilerOptions: {
+                            module: ModuleKind.CommonJS,
+                            newLine: NewLineKind.LineFeed,
+                            noEmitHelpers: true,
+                            emitDecoratorMetadata: true,
+                            experimentalDecorators: true,
+                            target: ScriptTarget.ES5,
+                        }
+                    }, 
+                    expectedOutput: output
+                });
+        });
     });
 }