fix TSTypeReference not printing typeArguments (#1392)

src/printer.js

@@ -1918,7 +1918,17 @@ function genericPrintNoParens(path, options, print, args) {
 
       return concat(parts);
     case "TSTypeReference":
-      return concat([path.call(print, "typeName")]);
+      parts.push(path.call(print, "typeName"))
+      
+      if (n.typeArguments) {
+        parts.push(
+          "<",
+          join(", ", path.map(print, "typeArguments")),
+          ">"
+        )
+      }
+      
+      return concat(parts);
     case "TSCallSignature":
       return concat([
         "(",

tests/typescript/conformance/types/typeReference/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,10 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`typeReference.ts 1`] = `
+let n: Promise<number>
+let m: Map<number, string>
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+let n: Promise<number>;
+let m: Map<number, string>;
+
+`;

tests/typescript/conformance/types/typeReference/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname, { parser: "typescript" });

tests/typescript/conformance/types/typeReference/typeReference.ts

@@ -0,0 +1,2 @@
+let n: Promise<number>
+let m: Map<number, string>