Fix extra semicolon in ambient typescript declaration emit (#2165) (#2167)

* fix(typescript): add failing ambient declaration test

* fix(typescript): fix failing test case for ambient function exports

src/printer.js

@@ -3165,7 +3165,8 @@ function printExportDeclaration(path, options, print) {
       decl.type === "ExportDefaultDeclaration" &&
       (decl.declaration.type !== "ClassDeclaration" &&
         decl.declaration.type !== "FunctionDeclaration" &&
-        decl.declaration.type !== "TSAbstractClassDeclaration")
+        decl.declaration.type !== "TSAbstractClassDeclaration" &&
+        decl.declaration.type !== "TSNamespaceFunctionDeclaration")
     ) {
       parts.push(semi);
     }

tests/typescript_ambient/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,38 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`ambient.ts 1`] = `
+declare module "classnames" {
+  export default function classnames(...inputs: (string | number | false | object | undefined)[]): string;
+  export class x {}
+  export interface y {}
+  export type z = y;
+}
+
+declare module "x" {
+  export default class x {}
+}
+
+declare module "y" {
+  const y = 5;
+  export default y;
+}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+declare module "classnames" {
+  export default function classnames(
+    ...inputs: (string | number | false | object | undefined)[]
+  ): string;
+  export class x {}
+  export interface y {}
+  export type z = y;
+}
+
+declare module "x" {
+  export default class x {}
+}
+
+declare module "y" {
+  const y = 5;
+  export default y;
+}
+
+`;

tests/typescript_ambient/ambient.ts

@@ -0,0 +1,15 @@
+declare module "classnames" {
+  export default function classnames(...inputs: (string | number | false | object | undefined)[]): string;
+  export class x {}
+  export interface y {}
+  export type z = y;
+}
+
+declare module "x" {
+  export default class x {}
+}
+
+declare module "y" {
+  const y = 5;
+  export default y;
+}

tests/typescript_ambient/jsfmt.spec.js

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