diff --git a/.travis.yml b/.travis.yml
index f22b70d5..01326f24 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -46,6 +46,7 @@ matrix:
         - npm ci --verbose
       script:
         - cargo test --release
+        - cargo test --target wasm32-unknown-unknown
         # Check JS output from all tests against eslint
         - npm run run-lint-generated-tests
         # Check Examples against eslint
diff --git a/Cargo.toml b/Cargo.toml
index 125c83f8..1fab54cb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -31,7 +31,10 @@ wasm-bindgen-macro = { path = "crates/macro", version = "=0.2.15" }
 serde = { version = "1.0", optional = true }
 serde_json = { version = "1.0", optional = true }
 
-[dev-dependencies]
+[target.'cfg(target_arch = "wasm32")'.dev-dependencies]
+wasm-bindgen-test = { path = 'crates/test', version = '=0.2.15' }
+
+[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
 wasm-bindgen-test-project-builder = { path = "crates/test-project-builder", version = '=0.2.15' }
 
 [workspace]
diff --git a/crates/cli/src/bin/wasm-bindgen-test-runner/main.rs b/crates/cli/src/bin/wasm-bindgen-test-runner/main.rs
index c900cbcd..466334f4 100644
--- a/crates/cli/src/bin/wasm-bindgen-test-runner/main.rs
+++ b/crates/cli/src/bin/wasm-bindgen-test-runner/main.rs
@@ -80,9 +80,7 @@ fn rmain() -> Result<(), Error> {
     fs::create_dir(&tmpdir)
         .context("creating temporary directory")?;
 
-    let module = wasm_file_to_test.file_stem()
-        .and_then(|s| s.to_str())
-        .ok_or_else(|| format_err!("invalid filename passed in"))?;
+    let module = "wasm-bindgen-test";
 
     // Collect all tests that the test harness is supposed to run. We assume
     // that any exported function with the prefix `__wbg_test` is a test we need
diff --git a/crates/cli/src/bin/wasm-bindgen-test-runner/node.rs b/crates/cli/src/bin/wasm-bindgen-test-runner/node.rs
index 49895e22..48c8dfe0 100644
--- a/crates/cli/src/bin/wasm-bindgen-test-runner/node.rs
+++ b/crates/cli/src/bin/wasm-bindgen-test-runner/node.rs
@@ -76,6 +76,7 @@ pub fn execute(module: &str, tmpdir: &Path, args: &[OsString], tests: &[String])
     let path = env::var("NODE_PATH").unwrap_or_default();
     let mut path = env::split_paths(&path).collect::<Vec<_>>();
     path.push(env::current_dir().unwrap());
+    path.push(tmpdir.to_path_buf());
     exec(
         Command::new("node")
             .env("NODE_PATH", env::join_paths(&path).unwrap())
diff --git a/tests/all/api.rs b/tests/all/api.rs
deleted file mode 100644
index 6de2739f..00000000
--- a/tests/all/api.rs
+++ /dev/null
@@ -1,233 +0,0 @@
-use super::project;
-
-#[test]
-fn works() {
-    project()
-        .file(
-            "src/lib.rs",
-            r#"
-                #![feature(use_extern_macros)]
-
-                extern crate wasm_bindgen;
-
-                use wasm_bindgen::prelude::*;
-
-                #[wasm_bindgen]
-                pub fn foo() -> JsValue {
-                    JsValue::from("foo")
-                }
-
-                #[wasm_bindgen]
-                pub fn bar(s: &str) -> JsValue {
-                    JsValue::from(s)
-                }
-
-                #[wasm_bindgen]
-                pub fn baz() -> JsValue {
-                    JsValue::from(1.0)
-                }
-
-                #[wasm_bindgen]
-                pub fn baz2(a: &JsValue, b: &JsValue) {
-                    assert_eq!(a.as_f64(), Some(2.0));
-                    assert_eq!(b.as_f64(), None);
-                }
-
-                #[wasm_bindgen]
-                pub fn js_null() -> JsValue {
-                    JsValue::null()
-                }
-
-                #[wasm_bindgen]
-                pub fn js_undefined() -> JsValue {
-                    JsValue::undefined()
-                }
-
-                #[wasm_bindgen]
-                pub fn test_is_null_undefined(
-                    a: &JsValue,
-                    b: &JsValue,
-                    c: &JsValue,
-                ) {
-                    assert!(a.is_null());
-                    assert!(!a.is_undefined());
-
-                    assert!(!b.is_null());
-                    assert!(b.is_undefined());
-
-                    assert!(!c.is_null());
-                    assert!(!c.is_undefined());
-                }
-
-                #[wasm_bindgen]
-                pub fn get_true() -> JsValue {
-                    JsValue::from(true)
-                }
-
-                #[wasm_bindgen]
-                pub fn get_false() -> JsValue {
-                    JsValue::from(false)
-                }
-
-                #[wasm_bindgen]
-                pub fn test_bool(
-                    a: &JsValue,
-                    b: &JsValue,
-                    c: &JsValue,
-                ) {
-                    assert_eq!(a.as_bool(), Some(true));
-                    assert_eq!(format!("{:?}", a), "true");
-                    assert_eq!(b.as_bool(), Some(false));
-                    assert_eq!(c.as_bool(), None);
-                }
-
-                #[wasm_bindgen]
-                pub fn mk_symbol() -> JsValue {
-                    let a = JsValue::symbol(None);
-                    assert!(a.is_symbol());
-                    assert_eq!(format!("{:?}", a), "Symbol(..)");
-                    return a
-                }
-
-                #[wasm_bindgen]
-                pub fn mk_symbol2(s: &str) -> JsValue {
-                    let a = JsValue::symbol(Some(s));
-                    assert!(a.is_symbol());
-                    return a
-                }
-
-                #[wasm_bindgen]
-                pub fn assert_symbols(a: &JsValue, b: &JsValue) {
-                    assert!(a.is_symbol());
-                    assert!(!b.is_symbol());
-                }
-
-                #[wasm_bindgen]
-                pub fn acquire_string(a: &JsValue, b: &JsValue) {
-                    assert_eq!(a.as_string().unwrap(), "foo");
-                    assert_eq!(format!("{:?}", a), "\"foo\"");
-                    assert_eq!(b.as_string(), None);
-                }
-
-                #[wasm_bindgen]
-                pub fn acquire_string2(a: &JsValue) -> String {
-                    a.as_string().unwrap_or("wrong".to_string())
-                }
-            "#,
-        )
-        .file(
-            "test.js",
-            r#"
-                import * as assert from "assert";
-                import * as wasm from "./out";
-
-                export function test() {
-                    assert.strictEqual(wasm.foo(), 'foo');
-                    assert.strictEqual(wasm.bar('a'), 'a');
-                    assert.strictEqual(wasm.baz(), 1);
-                    wasm.baz2(2, 'a');
-
-                    assert.strictEqual(wasm.js_null(), null);
-                    assert.strictEqual(wasm.js_undefined(), undefined);
-
-                    wasm.test_is_null_undefined(null, undefined, 1.0);
-
-                    assert.strictEqual(wasm.get_true(), true);
-                    assert.strictEqual(wasm.get_false(), false);
-                    wasm.test_bool(true, false, 1.0);
-
-                    assert.strictEqual(typeof(wasm.mk_symbol()), 'symbol');
-                    assert.strictEqual(typeof(wasm.mk_symbol2('a')), 'symbol');
-                    assert.strictEqual(Symbol.keyFor(wasm.mk_symbol()), undefined);
-                    assert.strictEqual(Symbol.keyFor(wasm.mk_symbol2('b')), undefined);
-
-                    wasm.assert_symbols(Symbol(), 'a');
-                    wasm.acquire_string('foo', null)
-                    assert.strictEqual(wasm.acquire_string2(''), '');
-                    assert.strictEqual(wasm.acquire_string2('a'), 'a');
-                }
-            "#,
-        )
-        .test();
-}
-
-#[test]
-fn eq_works() {
-    project()
-        .file(
-            "src/lib.rs",
-            r#"
-            #![feature(use_extern_macros)]
-
-            extern crate wasm_bindgen;
-
-            use wasm_bindgen::prelude::*;
-
-            #[wasm_bindgen]
-            pub fn test(a: &JsValue, b: &JsValue) -> bool {
-                a == b
-            }
-
-            #[wasm_bindgen]
-            pub fn test1(a: &JsValue) -> bool {
-                a == a
-            }
-        "#,
-        )
-        .file(
-            "test.js",
-            r#"
-                import * as assert from "assert";
-                import * as wasm from "./out";
-
-                export function test() {
-                    assert.strictEqual(wasm.test('a', 'a'), true);
-                    assert.strictEqual(wasm.test('a', 'b'), false);
-                    assert.strictEqual(wasm.test(NaN, NaN), false);
-                    assert.strictEqual(wasm.test({a: 'a'}, {a: 'a'}), false);
-                    assert.strictEqual(wasm.test1(NaN), false);
-                    let x = {a: 'a'};
-                    assert.strictEqual(wasm.test(x, x), true);
-                    assert.strictEqual(wasm.test1(x), true);
-                }
-            "#,
-        )
-        .test();
-}
-
-#[test]
-fn null_keeps_working() {
-    project()
-        .file(
-            "src/lib.rs",
-            r#"
-                #![feature(use_extern_macros)]
-
-                extern crate wasm_bindgen;
-
-                use wasm_bindgen::prelude::*;
-
-                #[wasm_bindgen(module = "./foo")]
-                extern {
-                    fn take_null(val: JsValue);
-                }
-
-                #[wasm_bindgen]
-                pub fn test() {
-                    take_null(JsValue::null());
-                    take_null(JsValue::null());
-                }
-            "#,
-        )
-        .file(
-            "foo.js",
-            r#"
-                import { strictEqual } from "assert";
-
-                export function take_null(n) {
-                    strictEqual(n, null);
-                }
-            "#,
-        )
-        .test();
-}
diff --git a/tests/all/main.rs b/tests/all/main.rs
index ec6592b6..ea2f150b 100644
--- a/tests/all/main.rs
+++ b/tests/all/main.rs
@@ -1,8 +1,9 @@
+#![cfg(not(target_arch = "wasm32"))]
+
 extern crate wasm_bindgen_test_project_builder as project_builder;
 
 use project_builder::{project, run};
 
-mod api;
 mod char;
 mod classes;
 mod closures;
diff --git a/tests/wasm/api.js b/tests/wasm/api.js
new file mode 100644
index 00000000..5f723f71
--- /dev/null
+++ b/tests/wasm/api.js
@@ -0,0 +1,43 @@
+const assert = require('assert');
+const wasm = require('wasm-bindgen-test.js');
+
+exports.test_works = function() {
+  assert.strictEqual(wasm.api_foo(), 'foo');
+  assert.strictEqual(wasm.api_bar('a'), 'a');
+  assert.strictEqual(wasm.api_baz(), 1);
+  wasm.api_baz2(2, 'a');
+
+  assert.strictEqual(wasm.api_js_null(), null);
+  assert.strictEqual(wasm.api_js_undefined(), undefined);
+
+  wasm.api_test_is_null_undefined(null, undefined, 1.0);
+
+  assert.strictEqual(wasm.api_get_true(), true);
+  assert.strictEqual(wasm.api_get_false(), false);
+  wasm.api_test_bool(true, false, 1.0);
+
+  assert.strictEqual(typeof(wasm.api_mk_symbol()), 'symbol');
+  assert.strictEqual(typeof(wasm.api_mk_symbol2('a')), 'symbol');
+  assert.strictEqual(Symbol.keyFor(wasm.api_mk_symbol()), undefined);
+  assert.strictEqual(Symbol.keyFor(wasm.api_mk_symbol2('b')), undefined);
+
+  wasm.api_assert_symbols(Symbol(), 'a');
+  wasm.api_acquire_string('foo', null);
+  assert.strictEqual(wasm.api_acquire_string2(''), '');
+  assert.strictEqual(wasm.api_acquire_string2('a'), 'a');
+};
+
+exports.test_eq_works = function() {
+  assert.strictEqual(wasm.eq_test('a', 'a'), true);
+  assert.strictEqual(wasm.eq_test('a', 'b'), false);
+  assert.strictEqual(wasm.eq_test(NaN, NaN), false);
+  assert.strictEqual(wasm.eq_test({a: 'a'}, {a: 'a'}), false);
+  assert.strictEqual(wasm.eq_test1(NaN), false);
+  let x = {a: 'a'};
+  assert.strictEqual(wasm.eq_test(x, x), true);
+  assert.strictEqual(wasm.eq_test1(x), true);
+};
+
+exports.assert_null = function(x) {
+  assert.strictEqual(x, null);
+};
diff --git a/tests/wasm/api.rs b/tests/wasm/api.rs
new file mode 100644
index 00000000..0b6ab5e1
--- /dev/null
+++ b/tests/wasm/api.rs
@@ -0,0 +1,137 @@
+use wasm_bindgen_test::*;
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen(module = "tests/wasm/api.js", version = "*")]
+extern {
+    fn test_works();
+    fn test_eq_works();
+    fn assert_null(v: JsValue);
+}
+
+#[wasm_bindgen_test]
+fn works() {
+    test_works();
+}
+
+#[wasm_bindgen]
+pub fn api_foo() -> JsValue {
+    JsValue::from("foo")
+}
+
+#[wasm_bindgen]
+pub fn api_bar(s: &str) -> JsValue {
+    JsValue::from(s)
+}
+
+#[wasm_bindgen]
+pub fn api_baz() -> JsValue {
+    JsValue::from(1.0)
+}
+
+#[wasm_bindgen]
+pub fn api_baz2(a: &JsValue, b: &JsValue) {
+    assert_eq!(a.as_f64(), Some(2.0));
+    assert_eq!(b.as_f64(), None);
+}
+
+#[wasm_bindgen]
+pub fn api_js_null() -> JsValue {
+    JsValue::null()
+}
+
+#[wasm_bindgen]
+pub fn api_js_undefined() -> JsValue {
+    JsValue::undefined()
+}
+
+#[wasm_bindgen]
+pub fn api_test_is_null_undefined(
+    a: &JsValue,
+    b: &JsValue,
+    c: &JsValue,
+) {
+    assert!(a.is_null());
+    assert!(!a.is_undefined());
+
+    assert!(!b.is_null());
+    assert!(b.is_undefined());
+
+    assert!(!c.is_null());
+    assert!(!c.is_undefined());
+}
+
+#[wasm_bindgen]
+pub fn api_get_true() -> JsValue {
+    JsValue::from(true)
+}
+
+#[wasm_bindgen]
+pub fn api_get_false() -> JsValue {
+    JsValue::from(false)
+}
+
+#[wasm_bindgen]
+pub fn api_test_bool(
+    a: &JsValue,
+    b: &JsValue,
+    c: &JsValue,
+) {
+    assert_eq!(a.as_bool(), Some(true));
+    assert_eq!(format!("{:?}", a), "true");
+    assert_eq!(b.as_bool(), Some(false));
+    assert_eq!(c.as_bool(), None);
+}
+
+#[wasm_bindgen]
+pub fn api_mk_symbol() -> JsValue {
+    let a = JsValue::symbol(None);
+    assert!(a.is_symbol());
+    assert_eq!(format!("{:?}", a), "Symbol(..)");
+    return a
+}
+
+#[wasm_bindgen]
+pub fn api_mk_symbol2(s: &str) -> JsValue {
+    let a = JsValue::symbol(Some(s));
+    assert!(a.is_symbol());
+    return a
+}
+
+#[wasm_bindgen]
+pub fn api_assert_symbols(a: &JsValue, b: &JsValue) {
+    assert!(a.is_symbol());
+    assert!(!b.is_symbol());
+}
+
+#[wasm_bindgen]
+pub fn api_acquire_string(a: &JsValue, b: &JsValue) {
+    assert_eq!(a.as_string().unwrap(), "foo");
+    assert_eq!(format!("{:?}", a), "\"foo\"");
+    assert_eq!(b.as_string(), None);
+}
+
+#[wasm_bindgen]
+pub fn api_acquire_string2(a: &JsValue) -> String {
+    a.as_string().unwrap_or("wrong".to_string())
+}
+
+#[wasm_bindgen_test]
+fn eq_works() {
+    test_eq_works();
+}
+
+#[wasm_bindgen]
+pub fn eq_test(a: &JsValue, b: &JsValue) -> bool {
+    a == b
+}
+
+#[wasm_bindgen]
+pub fn eq_test1(a: &JsValue) -> bool {
+    a == a
+}
+
+#[wasm_bindgen_test]
+fn null_keeps_working() {
+    assert_null(JsValue::null());
+    assert_null(JsValue::null());
+}
diff --git a/tests/wasm/main.rs b/tests/wasm/main.rs
new file mode 100644
index 00000000..0040850e
--- /dev/null
+++ b/tests/wasm/main.rs
@@ -0,0 +1,7 @@
+#![cfg(target_arch = "wasm32")]
+#![feature(use_extern_macros)]
+
+extern crate wasm_bindgen_test;
+extern crate wasm_bindgen;
+
+pub mod api;