diff --git a/internal/shader/shader_test.go b/internal/shader/shader_test.go
index c7e8496fd..cc8695c5a 100644
--- a/internal/shader/shader_test.go
+++ b/internal/shader/shader_test.go
@@ -17,338 +17,83 @@ package shader_test
 import (
 	"go/parser"
 	"go/token"
+	"io/ioutil"
+	"path/filepath"
+	"strings"
 	"testing"
 
 	. "github.com/hajimehoshi/ebiten/internal/shader"
 )
 
-func TestDump(t *testing.T) {
-	tests := []struct {
+func TestCompile(t *testing.T) {
+	files, err := ioutil.ReadDir("testdata")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	type testcase struct {
 		Name string
-		Src  string
-		VS   string
-		FS   string
-	}{
-		{
-			Name: "uniforms",
-			Src: `package main
-
-var (
-	Foo vec2
-	Boo vec4
-)`,
-			VS: `uniform vec2 U0;
-uniform vec4 U1;`,
-		},
-		{
-			Name: "func",
-			Src: `package main
-
-func Foo(foo vec2) vec4 {
-}`,
-			VS: `void F0(in vec2 l0, out vec4 l1) {
-}`,
-		},
-		{
-			Name: "func body",
-			Src: `package main
-
-func Foo(foo vec2) vec4 {
-	return vec4(foo, 0, 1)
-}`,
-			VS: `void F0(in vec2 l0, out vec4 l1) {
-	l1 = vec4(l0, 0.0, 1.0);
-	return;
-}`,
-		},
-		{
-			Name: "var init",
-			Src: `package main
-
-func Foo(foo vec2) vec4 {
-	var ret vec4 = vec4(foo, 0, 1)
-	return ret
-}`,
-			VS: `void F0(in vec2 l0, out vec4 l1) {
-	vec4 l2 = vec4(0.0);
-	l2 = vec4(l0, 0.0, 1.0);
-	l1 = l2;
-	return;
-}`,
-		},
-		{
-			Name: "var init 2",
-			Src: `package main
-
-func Foo(foo vec2) vec4 {
-	var bar1 vec4 = vec4(foo, 0, 1)
-	bar1.x = bar1.x
-	var bar2 vec4 = bar1
-	return bar2
-}`,
-			VS: `void F0(in vec2 l0, out vec4 l1) {
-	vec4 l2 = vec4(0.0);
-	vec4 l3 = vec4(0.0);
-	l2 = vec4(l0, 0.0, 1.0);
-	(l2).x = (l2).x;
-	l3 = l2;
-	l1 = l3;
-	return;
-}`,
-		},
-		{
-			Name: "var multiple init",
-			Src: `package main
-
-func Foo(foo vec2) vec4 {
-	var bar1, bar2 vec2 = foo, foo
-	return vec4(bar1, bar2)
-}`,
-			VS: `void F0(in vec2 l0, out vec4 l1) {
-	vec2 l2 = vec2(0.0);
-	vec2 l3 = vec2(0.0);
-	l2 = l0;
-	l3 = l0;
-	l1 = vec4(l2, l3);
-	return;
-}`,
-		},
-		{
-			Name: "multiple out params",
-			Src: `package main
-
-func Foo(foo vec4) (float, float, float, float) {
-	return foo.x, foo.y, foo.z, foo.w
-}`,
-			VS: `void F0(in vec4 l0, out float l1, out float l2, out float l3, out float l4) {
-	l1 = (l0).x;
-	l2 = (l0).y;
-	l3 = (l0).z;
-	l4 = (l0).w;
-	return;
-}`,
-		},
-		{
-			Name: "blocks",
-			Src: `package main
-
-func Foo(foo vec2) vec4 {
-	var r vec4
-	{
-		r.x = foo.x
-		var foo vec3
-		{
-			r.y = foo.y
-			var foo vec4
-			r.z = foo.z
-		}
-		{
-			r.y = foo.y
-			var foo vec4
-			r.z = foo.z
-		}
+		Src  []byte
+		VS   []byte
+		FS   []byte
 	}
-	return r
-}`,
-			VS: `void F0(in vec2 l0, out vec4 l1) {
-	vec4 l2 = vec4(0.0);
-	{
-		vec3 l3 = vec3(0.0);
-		(l2).x = (l0).x;
-		{
-			vec4 l4 = vec4(0.0);
-			(l2).y = (l3).y;
-			(l2).z = (l4).z;
+
+	fnames := map[string]struct{}{}
+	for _, f := range files {
+		if f.IsDir() {
+			continue
 		}
-		{
-			vec4 l4 = vec4(0.0);
-			(l2).y = (l3).y;
-			(l2).z = (l4).z;
+		fnames[f.Name()] = struct{}{}
+	}
+
+	tests := []testcase{}
+	for n := range fnames {
+		if !strings.HasSuffix(n, ".go") {
+			continue
 		}
+
+		src, err := ioutil.ReadFile(filepath.Join("testdata", n))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		name := n[:len(n)-len(".go")]
+		tc := testcase{
+			Name: name,
+			Src:  src,
+		}
+
+		vsn := name + ".expected.vs"
+		if _, ok := fnames[vsn]; ok {
+			vs, err := ioutil.ReadFile(filepath.Join("testdata", vsn))
+			if err != nil {
+				t.Fatal(err)
+			}
+			tc.VS = vs
+		}
+
+		fsn := name + ".expected.fs"
+		if _, ok := fnames[fsn]; ok {
+			fs, err := ioutil.ReadFile(filepath.Join("testdata", fsn))
+			if err != nil {
+				t.Fatal(err)
+			}
+			tc.FS = fs
+		}
+
+		if tc.VS == nil && tc.FS == nil {
+			t.Fatalf("no expected file for %s", name)
+		}
+
+		tests = append(tests, tc)
 	}
-	l1 = l2;
-	return;
-}`,
-		},
-		{
-			Name: "define",
-			Src: `package main
 
-func Foo(foo vec2) vec4 {
-	r := vec4(foo, 0, 1)
-	return r
-}`,
-			VS: `void F0(in vec2 l0, out vec4 l1) {
-	vec4 l2 = vec4(0.0);
-	l2 = vec4(l0, 0.0, 1.0);
-	l1 = l2;
-	return;
-}`,
-		},
-		{
-			Name: "call",
-			Src: `package main
-
-func Foo(x vec2) vec2 {
-	return Bar(x)
-}
-
-func Bar(x vec2) vec2 {
-	return x
-}`,
-			VS: `void F0(in vec2 l0, out vec2 l1) {
-	vec2 l2 = vec2(0.0);
-	F1(l0, l2);
-	l1 = l2;
-	return;
-}
-
-void F1(in vec2 l0, out vec2 l1) {
-	l1 = l0;
-	return;
-}`,
-		},
-		{
-			Name: "call multiple out params",
-			Src: `package main
-
-func Foo(x vec2) vec2 {
-	var xx, yx float = Bar(x.x, x.y)
-	return vec2(xx, yx)
-}
-
-func Bar(x float) (float, float) {
-	return x, x
-}`,
-			VS: `void F0(in vec2 l0, out vec2 l1) {
-	float l2 = 0.0;
-	float l3 = 0.0;
-	float l4 = 0.0;
-	float l5 = 0.0;
-	F1((l0).x, (l0).y, l2, l3);
-	l4 = l2;
-	l5 = l3;
-	l1 = vec2(l4, l5);
-	return;
-}
-
-void F1(in float l0, out float l1, out float l2) {
-	l1 = l0;
-	l2 = l0;
-	return;
-}`,
-		},
-		{
-			Name: "call multiple out params nested",
-			Src: `package main
-
-func Foo(x vec2) {
-	Bar(Bar(x.x, x.y))
-}
-
-func Bar(x, y float) (float, float) {
-	return x, y
-}`,
-			VS: `void F0(in vec2 l0) {
-	float l1 = 0.0;
-	float l2 = 0.0;
-	float l3 = 0.0;
-	float l4 = 0.0;
-	F1((l0).x, (l0).y, l1, l2);
-	F1(l1, l2, l3, l4);
-}
-
-void F1(in float l0, in float l1, out float l2, out float l3) {
-	l2 = l0;
-	l3 = l1;
-	return;
-}`,
-		},
-		{
-			Name: "vertex",
-			Src: `package main
-
-func Vertex(position vec2, texCoord vec2, color vec4) (position vec4, texCoord vec2, color vec4) {
-	projectionMatrix := mat4(
-		2 / ScreenSize.x, 0, 0, 0,
-		0, 2 / ScreenSize.y, 0, 0,
-		0, 0, 1, 0,
-		-1, -1, 0, 1,
-	)
-	return projectionMatrix * vec4(position, 0, 1), texCoord, color
-}
-
-var ScreenSize vec2`,
-			VS: `uniform vec2 U0;
-attribute vec2 A0;
-attribute vec2 A1;
-attribute vec4 A2;
-varying vec2 V0;
-varying vec4 V1;
-
-void main(void) {
-	mat4 l0 = mat4(0.0);
-	l0 = mat4((2.0) / ((U0).x), 0.0, 0.0, 0.0, 0.0, (2.0) / ((U0).y), 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, -(1.0), -(1.0), 0.0, 1.0);
-	gl_Position = (l0) * (vec4(A0, 0.0, 1.0));
-	V0 = A1;
-	V1 = A2;
-	return;
-}`,
-			FS: `uniform vec2 U0;
-varying vec2 V0;
-varying vec4 V1;`,
-		},
-		{
-			Name: "vertex and fragment",
-			Src: `package main
-
-func Vertex(position vec2, texCoord vec2, color vec4) (position vec4, texCoord vec2, color vec4) {
-	projectionMatrix := mat4(
-		2 / ScreenSize.x, 0, 0, 0,
-		0, 2 / ScreenSize.y, 0, 0,
-		0, 0, 1, 0,
-		-1, -1, 0, 1,
-	)
-	return projectionMatrix * vec4(position, 0, 1), texCoord, color
-}
-
-func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
-	return vec4(1, 0, 0, 1)
-}
-
-var ScreenSize vec2`,
-			VS: `uniform vec2 U0;
-attribute vec2 A0;
-attribute vec2 A1;
-attribute vec4 A2;
-varying vec2 V0;
-varying vec4 V1;
-
-void main(void) {
-	mat4 l0 = mat4(0.0);
-	l0 = mat4((2.0) / ((U0).x), 0.0, 0.0, 0.0, 0.0, (2.0) / ((U0).y), 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, -(1.0), -(1.0), 0.0, 1.0);
-	gl_Position = (l0) * (vec4(A0, 0.0, 1.0));
-	V0 = A1;
-	V1 = A2;
-	return;
-}`,
-			FS: `uniform vec2 U0;
-varying vec2 V0;
-varying vec4 V1;
-
-void main(void) {
-	gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
-	return;
-}`,
-		},
-	}
 	for _, tc := range tests {
 		t.Run(tc.Name, func(t *testing.T) {
 			fset := token.NewFileSet()
-			f, err := parser.ParseFile(fset, "", []byte(tc.Src), parser.AllErrors)
+			f, err := parser.ParseFile(fset, "", tc.Src, parser.AllErrors)
 			if err != nil {
 				t.Fatal(err)
-				return
 			}
 
 			s, err := Compile(fset, f, "Vertex", "Fragment")
@@ -357,11 +102,11 @@ void main(void) {
 				return
 			}
 			vs, fs := s.Glsl()
-			if got, want := vs, tc.VS+"\n"; got != want {
+			if got, want := vs, string(tc.VS); got != want {
 				t.Errorf("got: %v, want: %v", got, want)
 			}
-			if tc.FS != "" {
-				if got, want := fs, tc.FS+"\n"; got != want {
+			if tc.FS != nil {
+				if got, want := fs, string(tc.FS); got != want {
 					t.Errorf("got: %v, want: %v", got, want)
 				}
 			}
diff --git a/internal/shader/testdata/blocks.expected.vs b/internal/shader/testdata/blocks.expected.vs
new file mode 100644
index 000000000..92344ffe3
--- /dev/null
+++ b/internal/shader/testdata/blocks.expected.vs
@@ -0,0 +1,19 @@
+void F0(in vec2 l0, out vec4 l1) {
+	vec4 l2 = vec4(0.0);
+	{
+		vec3 l3 = vec3(0.0);
+		(l2).x = (l0).x;
+		{
+			vec4 l4 = vec4(0.0);
+			(l2).y = (l3).y;
+			(l2).z = (l4).z;
+		}
+		{
+			vec4 l4 = vec4(0.0);
+			(l2).y = (l3).y;
+			(l2).z = (l4).z;
+		}
+	}
+	l1 = l2;
+	return;
+}
diff --git a/internal/shader/testdata/blocks.go b/internal/shader/testdata/blocks.go
new file mode 100644
index 000000000..18d12d291
--- /dev/null
+++ b/internal/shader/testdata/blocks.go
@@ -0,0 +1,20 @@
+package main
+
+func Foo(foo vec2) vec4 {
+	var r vec4
+	{
+		r.x = foo.x
+		var foo vec3
+		{
+			r.y = foo.y
+			var foo vec4
+			r.z = foo.z
+		}
+		{
+			r.y = foo.y
+			var foo vec4
+			r.z = foo.z
+		}
+	}
+	return r
+}
diff --git a/internal/shader/testdata/call.expected.vs b/internal/shader/testdata/call.expected.vs
new file mode 100644
index 000000000..6355e652a
--- /dev/null
+++ b/internal/shader/testdata/call.expected.vs
@@ -0,0 +1,11 @@
+void F0(in vec2 l0, out vec2 l1) {
+	vec2 l2 = vec2(0.0);
+	F1(l0, l2);
+	l1 = l2;
+	return;
+}
+
+void F1(in vec2 l0, out vec2 l1) {
+	l1 = l0;
+	return;
+}
diff --git a/internal/shader/testdata/call.go b/internal/shader/testdata/call.go
new file mode 100644
index 000000000..f5fc6bcf6
--- /dev/null
+++ b/internal/shader/testdata/call.go
@@ -0,0 +1,9 @@
+package main
+
+func Foo(x vec2) vec2 {
+	return Bar(x)
+}
+
+func Bar(x vec2) vec2 {
+	return x
+}
diff --git a/internal/shader/testdata/call_multiple.expected.vs b/internal/shader/testdata/call_multiple.expected.vs
new file mode 100644
index 000000000..8c3157e38
--- /dev/null
+++ b/internal/shader/testdata/call_multiple.expected.vs
@@ -0,0 +1,17 @@
+void F0(in vec2 l0, out vec2 l1) {
+	float l2 = 0.0;
+	float l3 = 0.0;
+	float l4 = 0.0;
+	float l5 = 0.0;
+	F1((l0).x, (l0).y, l2, l3);
+	l4 = l2;
+	l5 = l3;
+	l1 = vec2(l4, l5);
+	return;
+}
+
+void F1(in float l0, out float l1, out float l2) {
+	l1 = l0;
+	l2 = l0;
+	return;
+}
diff --git a/internal/shader/testdata/call_multiple.go b/internal/shader/testdata/call_multiple.go
new file mode 100644
index 000000000..9e33b3f20
--- /dev/null
+++ b/internal/shader/testdata/call_multiple.go
@@ -0,0 +1,10 @@
+package main
+
+func Foo(x vec2) vec2 {
+	var xx, yx float = Bar(x.x, x.y)
+	return vec2(xx, yx)
+}
+
+func Bar(x float) (float, float) {
+	return x, x
+}
diff --git a/internal/shader/testdata/call_multiple_nested.expected.vs b/internal/shader/testdata/call_multiple_nested.expected.vs
new file mode 100644
index 000000000..7cc0592b6
--- /dev/null
+++ b/internal/shader/testdata/call_multiple_nested.expected.vs
@@ -0,0 +1,14 @@
+void F0(in vec2 l0) {
+	float l1 = 0.0;
+	float l2 = 0.0;
+	float l3 = 0.0;
+	float l4 = 0.0;
+	F1((l0).x, (l0).y, l1, l2);
+	F1(l1, l2, l3, l4);
+}
+
+void F1(in float l0, in float l1, out float l2, out float l3) {
+	l2 = l0;
+	l3 = l1;
+	return;
+}
diff --git a/internal/shader/testdata/call_multiple_nested.go b/internal/shader/testdata/call_multiple_nested.go
new file mode 100644
index 000000000..d5a708437
--- /dev/null
+++ b/internal/shader/testdata/call_multiple_nested.go
@@ -0,0 +1,9 @@
+package main
+
+func Foo(x vec2) {
+	Bar(Bar(x.x, x.y))
+}
+
+func Bar(x, y float) (float, float) {
+	return x, y
+}
diff --git a/internal/shader/testdata/define.expected.vs b/internal/shader/testdata/define.expected.vs
new file mode 100644
index 000000000..5cce79e0c
--- /dev/null
+++ b/internal/shader/testdata/define.expected.vs
@@ -0,0 +1,6 @@
+void F0(in vec2 l0, out vec4 l1) {
+	vec4 l2 = vec4(0.0);
+	l2 = vec4(l0, 0.0, 1.0);
+	l1 = l2;
+	return;
+}
diff --git a/internal/shader/testdata/define.go b/internal/shader/testdata/define.go
new file mode 100644
index 000000000..2157368b7
--- /dev/null
+++ b/internal/shader/testdata/define.go
@@ -0,0 +1,6 @@
+package main
+
+func Foo(foo vec2) vec4 {
+	r := vec4(foo, 0, 1)
+	return r
+}
diff --git a/internal/shader/testdata/func.expected.vs b/internal/shader/testdata/func.expected.vs
new file mode 100644
index 000000000..1caab6b77
--- /dev/null
+++ b/internal/shader/testdata/func.expected.vs
@@ -0,0 +1,2 @@
+void F0(in vec2 l0, out vec4 l1) {
+}
diff --git a/internal/shader/testdata/func.go b/internal/shader/testdata/func.go
new file mode 100644
index 000000000..d9d56263e
--- /dev/null
+++ b/internal/shader/testdata/func.go
@@ -0,0 +1,4 @@
+package main
+
+func Foo(foo vec2) vec4 {
+}
diff --git a/internal/shader/testdata/func_body.expected.vs b/internal/shader/testdata/func_body.expected.vs
new file mode 100644
index 000000000..2447550ab
--- /dev/null
+++ b/internal/shader/testdata/func_body.expected.vs
@@ -0,0 +1,4 @@
+void F0(in vec2 l0, out vec4 l1) {
+	l1 = vec4(l0, 0.0, 1.0);
+	return;
+}
diff --git a/internal/shader/testdata/func_body.go b/internal/shader/testdata/func_body.go
new file mode 100644
index 000000000..57d2e3e4e
--- /dev/null
+++ b/internal/shader/testdata/func_body.go
@@ -0,0 +1,5 @@
+package main
+
+func Foo(foo vec2) vec4 {
+	return vec4(foo, 0, 1)
+}
diff --git a/internal/shader/testdata/func_multiple.expected.vs b/internal/shader/testdata/func_multiple.expected.vs
new file mode 100644
index 000000000..81d83fd84
--- /dev/null
+++ b/internal/shader/testdata/func_multiple.expected.vs
@@ -0,0 +1,7 @@
+void F0(in vec4 l0, out float l1, out float l2, out float l3, out float l4) {
+	l1 = (l0).x;
+	l2 = (l0).y;
+	l3 = (l0).z;
+	l4 = (l0).w;
+	return;
+}
diff --git a/internal/shader/testdata/func_multiple.go b/internal/shader/testdata/func_multiple.go
new file mode 100644
index 000000000..4126a2e9e
--- /dev/null
+++ b/internal/shader/testdata/func_multiple.go
@@ -0,0 +1,5 @@
+package main
+
+func Foo(foo vec4) (float, float, float, float) {
+	return foo.x, foo.y, foo.z, foo.w
+}
diff --git a/internal/shader/testdata/uniforms.expected.vs b/internal/shader/testdata/uniforms.expected.vs
new file mode 100644
index 000000000..333178024
--- /dev/null
+++ b/internal/shader/testdata/uniforms.expected.vs
@@ -0,0 +1,2 @@
+uniform vec2 U0;
+uniform vec4 U1;
diff --git a/internal/shader/testdata/uniforms.go b/internal/shader/testdata/uniforms.go
new file mode 100644
index 000000000..dc6ed30bc
--- /dev/null
+++ b/internal/shader/testdata/uniforms.go
@@ -0,0 +1,6 @@
+package main
+
+var (
+	Foo vec2
+	Boo vec4
+)
diff --git a/internal/shader/testdata/var.expected.vs b/internal/shader/testdata/var.expected.vs
new file mode 100644
index 000000000..5cce79e0c
--- /dev/null
+++ b/internal/shader/testdata/var.expected.vs
@@ -0,0 +1,6 @@
+void F0(in vec2 l0, out vec4 l1) {
+	vec4 l2 = vec4(0.0);
+	l2 = vec4(l0, 0.0, 1.0);
+	l1 = l2;
+	return;
+}
diff --git a/internal/shader/testdata/var.go b/internal/shader/testdata/var.go
new file mode 100644
index 000000000..6a02de4ca
--- /dev/null
+++ b/internal/shader/testdata/var.go
@@ -0,0 +1,6 @@
+package main
+
+func Foo(foo vec2) vec4 {
+	var ret vec4 = vec4(foo, 0, 1)
+	return ret
+}
diff --git a/internal/shader/testdata/var2.expected.vs b/internal/shader/testdata/var2.expected.vs
new file mode 100644
index 000000000..39f20c6fb
--- /dev/null
+++ b/internal/shader/testdata/var2.expected.vs
@@ -0,0 +1,9 @@
+void F0(in vec2 l0, out vec4 l1) {
+	vec4 l2 = vec4(0.0);
+	vec4 l3 = vec4(0.0);
+	l2 = vec4(l0, 0.0, 1.0);
+	(l2).x = (l2).x;
+	l3 = l2;
+	l1 = l3;
+	return;
+}
diff --git a/internal/shader/testdata/var2.go b/internal/shader/testdata/var2.go
new file mode 100644
index 000000000..054dc38ba
--- /dev/null
+++ b/internal/shader/testdata/var2.go
@@ -0,0 +1,8 @@
+package main
+
+func Foo(foo vec2) vec4 {
+	var bar1 vec4 = vec4(foo, 0, 1)
+	bar1.x = bar1.x
+	var bar2 vec4 = bar1
+	return bar2
+}
diff --git a/internal/shader/testdata/var_multiple.expected.vs b/internal/shader/testdata/var_multiple.expected.vs
new file mode 100644
index 000000000..c10e14e34
--- /dev/null
+++ b/internal/shader/testdata/var_multiple.expected.vs
@@ -0,0 +1,8 @@
+void F0(in vec2 l0, out vec4 l1) {
+	vec2 l2 = vec2(0.0);
+	vec2 l3 = vec2(0.0);
+	l2 = l0;
+	l3 = l0;
+	l1 = vec4(l2, l3);
+	return;
+}
diff --git a/internal/shader/testdata/var_multiple.go b/internal/shader/testdata/var_multiple.go
new file mode 100644
index 000000000..8386fe836
--- /dev/null
+++ b/internal/shader/testdata/var_multiple.go
@@ -0,0 +1,6 @@
+package main
+
+func Foo(foo vec2) vec4 {
+	var bar1, bar2 vec2 = foo, foo
+	return vec4(bar1, bar2)
+}
diff --git a/internal/shader/testdata/vertex.expected.fs b/internal/shader/testdata/vertex.expected.fs
new file mode 100644
index 000000000..40d1c664e
--- /dev/null
+++ b/internal/shader/testdata/vertex.expected.fs
@@ -0,0 +1,3 @@
+uniform vec2 U0;
+varying vec2 V0;
+varying vec4 V1;
diff --git a/internal/shader/testdata/vertex.expected.vs b/internal/shader/testdata/vertex.expected.vs
new file mode 100644
index 000000000..59ca7a289
--- /dev/null
+++ b/internal/shader/testdata/vertex.expected.vs
@@ -0,0 +1,15 @@
+uniform vec2 U0;
+attribute vec2 A0;
+attribute vec2 A1;
+attribute vec4 A2;
+varying vec2 V0;
+varying vec4 V1;
+
+void main(void) {
+	mat4 l0 = mat4(0.0);
+	l0 = mat4((2.0) / ((U0).x), 0.0, 0.0, 0.0, 0.0, (2.0) / ((U0).y), 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, -(1.0), -(1.0), 0.0, 1.0);
+	gl_Position = (l0) * (vec4(A0, 0.0, 1.0));
+	V0 = A1;
+	V1 = A2;
+	return;
+}
diff --git a/internal/shader/testdata/vertex.go b/internal/shader/testdata/vertex.go
new file mode 100644
index 000000000..fa2fc12a8
--- /dev/null
+++ b/internal/shader/testdata/vertex.go
@@ -0,0 +1,13 @@
+package main
+
+func Vertex(position vec2, texCoord vec2, color vec4) (position vec4, texCoord vec2, color vec4) {
+	projectionMatrix := mat4(
+		2/ScreenSize.x, 0, 0, 0,
+		0, 2/ScreenSize.y, 0, 0,
+		0, 0, 1, 0,
+		-1, -1, 0, 1,
+	)
+	return projectionMatrix * vec4(position, 0, 1), texCoord, color
+}
+
+var ScreenSize vec2
diff --git a/internal/shader/testdata/vertex_fragment.expected.fs b/internal/shader/testdata/vertex_fragment.expected.fs
new file mode 100644
index 000000000..b0d7975eb
--- /dev/null
+++ b/internal/shader/testdata/vertex_fragment.expected.fs
@@ -0,0 +1,8 @@
+uniform vec2 U0;
+varying vec2 V0;
+varying vec4 V1;
+
+void main(void) {
+	gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);
+	return;
+}
diff --git a/internal/shader/testdata/vertex_fragment.expected.vs b/internal/shader/testdata/vertex_fragment.expected.vs
new file mode 100644
index 000000000..59ca7a289
--- /dev/null
+++ b/internal/shader/testdata/vertex_fragment.expected.vs
@@ -0,0 +1,15 @@
+uniform vec2 U0;
+attribute vec2 A0;
+attribute vec2 A1;
+attribute vec4 A2;
+varying vec2 V0;
+varying vec4 V1;
+
+void main(void) {
+	mat4 l0 = mat4(0.0);
+	l0 = mat4((2.0) / ((U0).x), 0.0, 0.0, 0.0, 0.0, (2.0) / ((U0).y), 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, -(1.0), -(1.0), 0.0, 1.0);
+	gl_Position = (l0) * (vec4(A0, 0.0, 1.0));
+	V0 = A1;
+	V1 = A2;
+	return;
+}
diff --git a/internal/shader/testdata/vertex_fragment.go b/internal/shader/testdata/vertex_fragment.go
new file mode 100644
index 000000000..0c06f832b
--- /dev/null
+++ b/internal/shader/testdata/vertex_fragment.go
@@ -0,0 +1,17 @@
+package main
+
+func Vertex(position vec2, texCoord vec2, color vec4) (position vec4, texCoord vec2, color vec4) {
+	projectionMatrix := mat4(
+		2/ScreenSize.x, 0, 0, 0,
+		0, 2/ScreenSize.y, 0, 0,
+		0, 0, 1, 0,
+		-1, -1, 0, 1,
+	)
+	return projectionMatrix * vec4(position, 0, 1), texCoord, color
+}
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	return vec4(1, 0, 0, 1)
+}
+
+var ScreenSize vec2