diff --git a/feature_tests/js/api/OptionInputStruct.d.ts b/feature_tests/js/api/OptionInputStruct.d.ts
index 04c9d834d..5e7bf96f1 100644
--- a/feature_tests/js/api/OptionInputStruct.d.ts
+++ b/feature_tests/js/api/OptionInputStruct.d.ts
@@ -3,9 +3,9 @@ import type { OptionEnum } from "./OptionEnum"
 import type { pointer, codepoint } from "./diplomat-runtime.d.ts";
 
 type OptionInputStruct_Obj = {
-    a: number | null;
-    b: codepoint | null;
-    c: OptionEnum | null;
+    a?: number | null;
+    b?: codepoint | null;
+    c?: OptionEnum | null;
 };
 
 export class OptionInputStruct {
diff --git a/feature_tests/js/test/.gitignore b/feature_tests/js/test/.gitignore
new file mode 100644
index 000000000..9044a0c52
--- /dev/null
+++ b/feature_tests/js/test/.gitignore
@@ -0,0 +1 @@
+*.mjs
\ No newline at end of file
diff --git a/feature_tests/js/test/attrs-ts.mjs b/feature_tests/js/test/attrs-ts.mjs
deleted file mode 100644
index 8634d331c..000000000
--- a/feature_tests/js/test/attrs-ts.mjs
+++ /dev/null
@@ -1,10 +0,0 @@
-import test from "ava";
-import { RenamedMyIterable } from "diplomat-wasm-js-feature-tests";
-test("Verify Iterables and Iterators", t => {
-    let iterable = RenamedMyIterable.new_([10, 20, 30, 40, 50]);
-    let start = 10;
-    for (let i of iterable) {
-        t.is(i, start);
-        start += 10;
-    }
-});
diff --git a/feature_tests/js/test/attrs.mjs b/feature_tests/js/test/attrs.mjs
deleted file mode 100644
index d8c5bf726..000000000
--- a/feature_tests/js/test/attrs.mjs
+++ /dev/null
@@ -1,13 +0,0 @@
-import test from "ava";
-
-import { RenamedMyIterable } from "diplomat-wasm-js-feature-tests";
-
-test("Verify Iterables and Iterators", t => {
-	let iterable = RenamedMyIterable.new_([10, 20, 30, 40, 50]);
-
-	let start = 10;
-	for (let i of iterable) {
-		t.is(i, start);
-		start += 10;
-	}
-});
\ No newline at end of file
diff --git a/feature_tests/js/test/lifetimes-ts.mjs b/feature_tests/js/test/lifetimes-ts.mjs
deleted file mode 100644
index bef12bab4..000000000
--- a/feature_tests/js/test/lifetimes-ts.mjs
+++ /dev/null
@@ -1,10 +0,0 @@
-import test from 'ava';
-import { Foo } from "diplomat-wasm-js-feature-tests";
-test("Foo", (t) => {
-    let f = Foo.new_("This is a test string.");
-    t.not(f.ffiValue, null);
-    let returning = f.asReturning();
-    t.is(returning.bytes.toString(), "This is a test string.");
-    let b = f.bar.foo.asReturning().bytes;
-    t.is(b.toString(), "This is a test string.");
-});
diff --git a/feature_tests/js/test/lifetimes.mjs b/feature_tests/js/test/lifetimes.mjs
deleted file mode 100644
index 7e7e74d2a..000000000
--- a/feature_tests/js/test/lifetimes.mjs
+++ /dev/null
@@ -1,13 +0,0 @@
-import test from 'ava';
-import { Foo } from "diplomat-wasm-js-feature-tests";
-
-test("Foo", (t) => {
-	let f = Foo.new_("This is a test string.");
-	t.not(f.ffiValue, null);
-
-	let returning = f.asReturning();
-	t.is(returning.bytes.toString(), "This is a test string.");
-
-	let b = f.bar.foo.asReturning().bytes;
-	t.is(b.toString(), "This is a test string.");
-});
\ No newline at end of file
diff --git a/feature_tests/js/test/option-ts.mjs b/feature_tests/js/test/option-ts.mjs
deleted file mode 100644
index 31c874604..000000000
--- a/feature_tests/js/test/option-ts.mjs
+++ /dev/null
@@ -1,18 +0,0 @@
-import test from 'ava';
-import { OptionOpaque } from "diplomat-wasm-js-feature-tests";
-test("Verify option methods", t => {
-    const o = OptionOpaque.new_(5);
-    o.assertInteger(5);
-    const on = OptionOpaque.newNone();
-    t.assert(on === null);
-    const s = OptionOpaque.newStruct();
-    s.a.assertInteger(101);
-    s.b.assertChar('餐'.codePointAt(0));
-    t.is(s.c, 904);
-    s.d.assertInteger(926535);
-    const sn = OptionOpaque.newStructNones();
-    t.assert(!sn.a);
-    t.assert(!sn.b);
-    t.is(sn.c, 908);
-    t.assert(!sn.d);
-});
diff --git a/feature_tests/js/test/option-ts.mts b/feature_tests/js/test/option-ts.mts
index 6f61ec93b..73c531e06 100644
--- a/feature_tests/js/test/option-ts.mts
+++ b/feature_tests/js/test/option-ts.mts
@@ -1,20 +1,20 @@
 import test from 'ava';
 
-import { OptionOpaque } from "diplomat-wasm-js-feature-tests";
+import { OptionOpaque, OptionEnum, OptionInputStruct } from "diplomat-wasm-js-feature-tests";
 
 test("Verify option methods", t => {
     const o = OptionOpaque.new_(5);
-    o!.assertInteger(5);
+    o.assertInteger(5);
 
     const on = OptionOpaque.newNone();
-    t.assert(on === null);
+    t.assert(!on);
 
     const s = OptionOpaque.newStruct();
 
-    s.a!.assertInteger(101);
-    s.b!.assertChar('餐'.codePointAt(0));
-    t.is(s.c!, 904);
-    s.d!.assertInteger(926535);
+    s.a.assertInteger(101);
+    s.b.assertChar('餐'.codePointAt(0));
+    t.is(s.c, 904);
+    s.d.assertInteger(926535);
 
     const sn = OptionOpaque.newStructNones();
     t.assert(!sn.a);
@@ -22,3 +22,24 @@ test("Verify option methods", t => {
     t.is(sn.c, 908);
     t.assert(!sn.d);
 });
+
+test("DiplomatOption tests", t => {
+    let maybeU8 = OptionOpaque.acceptsOptionU8(null);
+    t.assert(maybeU8 === null);
+    maybeU8 = OptionOpaque.acceptsOptionU8(47);
+    t.is(maybeU8, 47);
+
+    let maybeStruct = OptionOpaque.acceptsOptionInputStruct(null);
+    t.assert(maybeStruct === null);
+    maybeStruct = OptionOpaque.acceptsOptionInputStruct(new OptionInputStruct({a: 7, c: OptionEnum.Bar}));
+    t.is(maybeStruct.a, 7);
+    t.assert(maybeStruct.b === null);
+    t.is(maybeStruct.c.value, OptionEnum.Bar.value);
+
+
+    let struct = OptionOpaque.returnsOptionInputStruct();
+    t.is(struct.a, 6);
+    t.assert(struct.b === null);
+    t.is(struct.c.value, OptionEnum.Bar.value);
+
+});
\ No newline at end of file
diff --git a/feature_tests/js/test/option.mjs b/feature_tests/js/test/option.mjs
deleted file mode 100644
index 829536add..000000000
--- a/feature_tests/js/test/option.mjs
+++ /dev/null
@@ -1,45 +0,0 @@
-import test from 'ava';
-
-import { OptionOpaque, OptionInputStruct, OptionEnum } from "diplomat-wasm-js-feature-tests";
-
-test("Verify option methods", t => {
-    const o = OptionOpaque.new_(5);
-    o.assertInteger(5);
-
-    const on = OptionOpaque.newNone();
-    t.assert(!on);
-
-    const s = OptionOpaque.newStruct();
-
-    s.a.assertInteger(101);
-    s.b.assertChar('餐'.codePointAt(0));
-    t.is(s.c, 904);
-    s.d.assertInteger(926535);
-
-    const sn = OptionOpaque.newStructNones();
-    t.assert(!sn.a);
-    t.assert(!sn.b);
-    t.is(sn.c, 908);
-    t.assert(!sn.d);
-});
-
-test("DiplomatOption tests", t => {
-    let maybeU8 = OptionOpaque.acceptsOptionU8(null);
-    t.assert(maybeU8 === null);
-    maybeU8 = OptionOpaque.acceptsOptionU8(47);
-    t.is(maybeU8, 47);
-
-    let maybeStruct = OptionOpaque.acceptsOptionInputStruct(null);
-    t.assert(maybeStruct === null);
-    maybeStruct = OptionOpaque.acceptsOptionInputStruct(new OptionInputStruct({a: 7, c: OptionEnum.Bar}));
-    t.is(maybeStruct.a, 7);
-    t.assert(maybeStruct.b === null);
-    t.is(maybeStruct.c.value, OptionEnum.Bar.value);
-
-
-    let struct = OptionOpaque.returnsOptionInputStruct();
-    t.is(struct.a, 6);
-    t.assert(struct.b === null);
-    t.is(struct.c.value, OptionEnum.Bar.value);
-
-});
diff --git a/feature_tests/js/test/result-ts.mjs b/feature_tests/js/test/result-ts.mjs
deleted file mode 100644
index f45dd3027..000000000
--- a/feature_tests/js/test/result-ts.mjs
+++ /dev/null
@@ -1,24 +0,0 @@
-import test from 'ava';
-import { ErrorEnum, MyStruct, ResultOpaque } from 'diplomat-wasm-js-feature-tests';
-test('Verify result methods', t => {
-    const s = ResultOpaque.new_(5);
-    s.assertInteger(5);
-    const error1 = t.throws(() => ResultOpaque.newFailingFoo());
-    t.is(error1.message, 'ErrorEnum: Foo');
-    t.is(error1.cause, ErrorEnum.Foo);
-    const error2 = t.throws(() => ResultOpaque.newFailingBar());
-    t.is(error2.message, 'ErrorEnum: Bar');
-    t.is(error2.cause, ErrorEnum.Bar);
-    t.is(ResultOpaque.newFailingUnit(), null);
-    const error3 = t.throws(() => ResultOpaque.newFailingStruct(109));
-    t.is(error3.message, 'ErrorStruct: [object Object]');
-    t.is(error3.cause.i, 109);
-    const error4 = t.throws(() => ResultOpaque.newInErr(559));
-    t.is(error4.message, 'ResultOpaque: [object Object]');
-    error4.cause.assertInteger(559);
-    const error5 = t.throws(() => ResultOpaque.newInEnumErr(881));
-    t.is(error5.message, 'ResultOpaque: [object Object]');
-    error5.cause.assertInteger(881);
-    const error6 = t.throws(() => MyStruct.failsZstResult());
-    t.is(error6.message, "MyZst");
-});
diff --git a/feature_tests/js/test/result.mjs b/feature_tests/js/test/result.mjs
deleted file mode 100644
index bc5cd4c39..000000000
--- a/feature_tests/js/test/result.mjs
+++ /dev/null
@@ -1,33 +0,0 @@
-import test from 'ava';
-
-import { ErrorEnum, ResultOpaque, MyStruct } from "diplomat-wasm-js-feature-tests"
-
-test("Verify result methods", t => {
-    const s = ResultOpaque.new_(5);
-    s.assertInteger(5);
-
-    const error1 = t.throws(() => ResultOpaque.newFailingFoo());
-    t.is(error1.message, "ErrorEnum: Foo");
-    t.is(error1.cause, ErrorEnum.Foo);
-
-    const error2 = t.throws(() => ResultOpaque.newFailingBar());
-    t.is(error2.message, "ErrorEnum: Bar");
-    t.is(error2.cause, ErrorEnum.Bar);
-
-    t.is(ResultOpaque.newFailingUnit(), null);
-
-    const error3 = t.throws(() => ResultOpaque.newFailingStruct(109));
-    t.is(error3.message, "ErrorStruct: [object Object]")
-    t.is(error3.cause.i, 109);
-
-    const error4 = t.throws(() => ResultOpaque.newInErr(559));
-    t.is(error4.message, "ResultOpaque: [object Object]");
-    error4.cause.assertInteger(559);
-
-    const error5 = t.throws(() => ResultOpaque.newInEnumErr(881));
-    t.is(error5.message, "ResultOpaque: [object Object]");
-    error5.cause.assertInteger(881);
-
-    const error6 = t.throws(() => MyStruct.failsZstResult());
-    t.is(error6.message, "MyZst");
-});
diff --git a/feature_tests/js/test/slices-ts.mjs b/feature_tests/js/test/slices-ts.mjs
deleted file mode 100644
index a675bda02..000000000
--- a/feature_tests/js/test/slices-ts.mjs
+++ /dev/null
@@ -1,19 +0,0 @@
-import test from "ava";
-import { MyString, Float64Vec } from "diplomat-wasm-js-feature-tests";
-test("MyString functionality", (t) => {
-    let str = MyString.new_("This is a test value.");
-    t.is(str.str, "This is a test value.");
-});
-test("String List", (t) => {
-    let str = MyString.newFromFirst(["This", "is", "a", "test."]);
-    t.is(str.str, "This");
-});
-test("MyString borrow", (t) => {
-    let str = MyString.new_("This is a test.");
-    t.is(str.borrow(), "This is a test.");
-});
-test("Float64Vec", (t) => {
-    let input = [1, 2, 3, 4, 5];
-    let data = Float64Vec.newIsize(input);
-    t.deepEqual(data.borrow(), input);
-});
diff --git a/feature_tests/js/test/slices-ts.mts b/feature_tests/js/test/slices-ts.mts
index bad6434f8..4b22a8e58 100644
--- a/feature_tests/js/test/slices-ts.mts
+++ b/feature_tests/js/test/slices-ts.mts
@@ -1,6 +1,5 @@
 import test from "ava";
 import { MyString, Float64Vec } from "diplomat-wasm-js-feature-tests";
-import wasm from "../api/diplomat-wasm.mjs";
 
 test("MyString functionality", (t) => {
   let str = MyString.new_("This is a test value.");
diff --git a/feature_tests/js/test/slices.mjs b/feature_tests/js/test/slices.mjs
deleted file mode 100644
index 4b22a8e58..000000000
--- a/feature_tests/js/test/slices.mjs
+++ /dev/null
@@ -1,23 +0,0 @@
-import test from "ava";
-import { MyString, Float64Vec } from "diplomat-wasm-js-feature-tests";
-
-test("MyString functionality", (t) => {
-  let str = MyString.new_("This is a test value.");
-  t.is(str.str, "This is a test value.");
-});
-
-test("String List", (t) => {
-  let str = MyString.newFromFirst(["This", "is", "a", "test."]);
-  t.is(str.str, "This");
-});
-
-test("MyString borrow", (t) => {
-  let str = MyString.new_("This is a test.");
-  t.is(str.borrow(), "This is a test.");
-});
-
-test("Float64Vec", (t) => {
-  let input = [1, 2, 3, 4, 5];
-  let data = Float64Vec.newIsize(input);
-  t.deepEqual(data.borrow(), input);
-});
diff --git a/feature_tests/js/test/struct-ts.mjs b/feature_tests/js/test/struct-ts.mjs
deleted file mode 100644
index ff9a237bc..000000000
--- a/feature_tests/js/test/struct-ts.mjs
+++ /dev/null
@@ -1,33 +0,0 @@
-import test from 'ava';
-import { MyEnum, MyStruct, CyclicStructB } from "diplomat-wasm-js-feature-tests";
-test("Verify invariants of struct", t => {
-    const s = MyStruct.new_();
-    t.is(s.a, 17);
-    t.is(s.b, true);
-    t.is(s.c, 209);
-    t.is(s.d, 1234n);
-    t.is(s.e, 5991);
-    t.is(s.f, '餐'.codePointAt(0));
-    t.is(s.g, MyEnum.B);
-    t.is(s.intoA(), 17);
-});
-test("Test struct creation", t => {
-    const s = new MyStruct({
-        a: 17,
-        b: true,
-        c: 209,
-        d: 1234n,
-        e: 5991,
-        f: '餐'.codePointAt(0),
-        g: MyEnum.B
-    });
-    t.is(s.intoA(), 17);
-});
-test("Function Returning Nested Struct of One Field", t => {
-    const a = CyclicStructB.getA();
-    t.is(a.cyclicOut(), "0");
-});
-test("Function De-Referencing Nested Struct of One Primitive", t => {
-    const a = CyclicStructB.getAOption();
-    t.is(a.cyclicOut(), "0");
-});
diff --git a/feature_tests/js/test/struct-ts.mts b/feature_tests/js/test/struct-ts.mts
index 2a0efc56c..878edb061 100644
--- a/feature_tests/js/test/struct-ts.mts
+++ b/feature_tests/js/test/struct-ts.mts
@@ -1,5 +1,5 @@
 import test from 'ava';
-import { MyEnum, MyStruct, CyclicStructB } from "diplomat-wasm-js-feature-tests";
+import { MyEnum, MyStruct, CyclicStructB, ScalarPairWithPadding, BigStructWithStuff } from "diplomat-wasm-js-feature-tests";
 
 test("Verify invariants of struct", t => {
     const s = MyStruct.new_();
@@ -26,7 +26,28 @@ test("Test struct creation", t => {
     t.is(s.intoA(), 17);
 });
 
-test("Function Returning Nested Struct of One Field", t => {
+test("Test struct layout: scalar pair layout", t => {
+    const s = new ScalarPairWithPadding({
+        first: 122,
+        second: 414
+    });
+    s.assertValue();
+    t.is(true, true); // Ava doesn't like tests without assertions
+});
+
+test("Test struct layout: complex struct with multiple padding types and contained scalar pair", t => {
+    const s = new BigStructWithStuff({
+        first: 101, 
+        second: 505, 
+        third: 9345,
+        fourth: new ScalarPairWithPadding({first: 122, second: 414}),
+        fifth: 99
+    });
+    s.assertValue(853);
+    t.is(true, true); // Ava doesn't like tests without assertions
+});
+
+test("Function Returning Nested Struct of One Primitive", t => {
     const a = CyclicStructB.getA();
     t.is(a.cyclicOut(), "0");
 });
diff --git a/feature_tests/js/test/struct.mjs b/feature_tests/js/test/struct.mjs
deleted file mode 100644
index 31041f43f..000000000
--- a/feature_tests/js/test/struct.mjs
+++ /dev/null
@@ -1,58 +0,0 @@
-import test from 'ava';
-import { MyEnum, MyStruct, ScalarPairWithPadding, BigStructWithStuff, CyclicStructB } from "diplomat-wasm-js-feature-tests";
-
-test("Verify invariants of struct", t => {
-    const s = MyStruct.new_("hello");
-    t.is(s.a, 17);
-    t.is(s.b, true);
-    t.is(s.c, 209);
-    t.is(s.d, 1234n);
-    t.is(s.e, 5991);
-    t.is(s.f, '餐'.codePointAt(0));
-    t.is(s.g, MyEnum.B);
-    t.is(s.intoA(), 17);
-});
-
-test("Test struct creation", t => {
-    const s = new MyStruct({
-        a: 17,
-        b: true,
-        c: 209,
-        d: 1234n,
-        e: 5991,
-        f: '餐'.codePointAt(0),
-        g: MyEnum.B
-    });
-    t.is(s.intoA(), 17);
-});
-
-test("Test struct layout: scalar pair layout", t => {
-    const s = new ScalarPairWithPadding({
-        first: 122,
-        second: 414
-    });
-    s.assertValue();
-    t.is(true, true); // Ava doesn't like tests without assertions
-});
-
-test("Test struct layout: complex struct with multiple padding types and contained scalar pair", t => {
-    const s = new BigStructWithStuff({
-        first: 101, 
-        second: 505, 
-        third: 9345,
-        fourth: new ScalarPairWithPadding({first: 122, second: 414}),
-        fifth: 99
-    });
-    s.assertValue(853);
-    t.is(true, true); // Ava doesn't like tests without assertions
-});
-
-test("Function Returning Nested Struct of One Primitive", t => {
-    const a = CyclicStructB.getA();
-    t.is(a.cyclicOut(), "0");
-});
-
-test("Function De-Referencing Nested Struct of One Primitive", t => {
-    const a = CyclicStructB.getAOption();
-    t.is(a.cyclicOut(), "0");
-});
\ No newline at end of file
diff --git a/tool/templates/js/struct.js.jinja b/tool/templates/js/struct.js.jinja
index b79a77af7..7bf313d53 100644
--- a/tool/templates/js/struct.js.jinja
+++ b/tool/templates/js/struct.js.jinja
@@ -6,7 +6,7 @@
 {%- if typescript && !is_out -%}
 type {{type_name}}_Obj = {
     {%- for field in fields %}
-    {{field.field_name}}: {{field.js_type_name}};
+    {{field.field_name}} {%- if let Type::DiplomatOption(o) = field.field_type %}?{% endif %}: {{field.js_type_name}};
     {%- endfor %}
 };