diff --git a/tests/typescript/declare/__snapshots__/jsfmt.spec.js.snap b/tests/typescript/declare/__snapshots__/jsfmt.spec.js.snap
index 9f673f0da2f3..fe39e136e522 100644
--- a/tests/typescript/declare/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/typescript/declare/__snapshots__/jsfmt.spec.js.snap
@@ -110,11 +110,23 @@ declare interface Dictionary<T> {
   [index: string]: T
 }
 
+declare interface B {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+}
+
 =====================================output=====================================
 declare interface Dictionary<T> {
   [index: string]: T;
 }
 
+declare interface B {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+}
+
 ================================================================================
 `;
 
diff --git a/tests/typescript/declare/declare_interface.ts b/tests/typescript/declare/declare_interface.ts
index 77a9962cd03a..14e4bfe6177d 100644
--- a/tests/typescript/declare/declare_interface.ts
+++ b/tests/typescript/declare/declare_interface.ts
@@ -1,3 +1,9 @@
 declare interface Dictionary<T> {
   [index: string]: T
 }
+
+declare interface B {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+}
diff --git a/tests/typescript/interface/__snapshots__/jsfmt.spec.js.snap b/tests/typescript/interface/__snapshots__/jsfmt.spec.js.snap
index 393512f5267e..6c3b914cd00c 100644
--- a/tests/typescript/interface/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/typescript/interface/__snapshots__/jsfmt.spec.js.snap
@@ -844,6 +844,51 @@ export interface ThirdVeryLongAndBoringInterfaceName
 ================================================================================
 `;
 
+exports[`pattern-parameters.ts - {"semi":false} format 1`] = `
+====================================options=====================================
+parsers: ["typescript"]
+printWidth: 80
+semi: false
+                                                                                | printWidth
+=====================================input======================================
+interface B {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+}
+
+=====================================output=====================================
+interface B {
+  foo([]?): void
+  bar({}, []?): any
+  baz(a: string, b: number, []?): void
+}
+
+================================================================================
+`;
+
+exports[`pattern-parameters.ts format 1`] = `
+====================================options=====================================
+parsers: ["typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+interface B {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+}
+
+=====================================output=====================================
+interface B {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+}
+
+================================================================================
+`;
+
 exports[`separator.ts - {"semi":false} format 1`] = `
 ====================================options=====================================
 parsers: ["typescript"]
diff --git a/tests/typescript/interface/pattern-parameters.ts b/tests/typescript/interface/pattern-parameters.ts
new file mode 100644
index 000000000000..f1cf8d0d3d73
--- /dev/null
+++ b/tests/typescript/interface/pattern-parameters.ts
@@ -0,0 +1,5 @@
+interface B {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+}
diff --git a/tests/typescript/type-alias/__snapshots__/jsfmt.spec.js.snap b/tests/typescript/type-alias/__snapshots__/jsfmt.spec.js.snap
new file mode 100644
index 000000000000..7f2c78b4eb82
--- /dev/null
+++ b/tests/typescript/type-alias/__snapshots__/jsfmt.spec.js.snap
@@ -0,0 +1,23 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`pattern-parameter.ts format 1`] = `
+====================================options=====================================
+parsers: ["typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+type C = {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+};
+
+=====================================output=====================================
+type C = {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+};
+
+================================================================================
+`;
diff --git a/tests/typescript/type-alias/jsfmt.spec.js b/tests/typescript/type-alias/jsfmt.spec.js
new file mode 100644
index 000000000000..2ea3bb6eb2e4
--- /dev/null
+++ b/tests/typescript/type-alias/jsfmt.spec.js
@@ -0,0 +1 @@
+run_spec(__dirname, ["typescript"]);
diff --git a/tests/typescript/type-alias/pattern-parameter.ts b/tests/typescript/type-alias/pattern-parameter.ts
new file mode 100644
index 000000000000..6880a5bff23a
--- /dev/null
+++ b/tests/typescript/type-alias/pattern-parameter.ts
@@ -0,0 +1,5 @@
+type C = {
+  foo([]?): void;
+  bar({}, []?): any;
+  baz(a: string, b: number, []?): void;
+};