diff --git a/Tupfile.rules b/Tupfile.rules
index 6c7b69a..271061b 100644
--- a/Tupfile.rules
+++ b/Tupfile.rules
@@ -1 +1,3 @@
 .gitignore
+
+: *_test.go |> go test -v -cover -race -o %o |> ./bin/%d.test
diff --git a/cmd/land/Tupfile b/cmd/land/Tupfile
index 5e7a943..625d9cd 100644
--- a/cmd/land/Tupfile
+++ b/cmd/land/Tupfile
@@ -1 +1,3 @@
+include_rules
+
 : *.go |> go build -o %o |> ../../bin/land
diff --git a/cmd/land/main.go b/cmd/land/main.go
index 5f0c46c..1aa046b 100644
--- a/cmd/land/main.go
+++ b/cmd/land/main.go
@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"flag"
+	"fmt"
 	"os"
 
 	"github.com/Xe/ln"
@@ -29,24 +30,7 @@ func main() {
 		ln.FatalErr(ctx, err, ln.F{"msg": "can't create process", "fname": fname})
 	}
 
-	foundMain := false
-	mainID := uint32(0)
-	for name, entry := range p.mod.Export.Entries {
-		if name == "main" && entry.FieldStr == "main" {
-			mainID = entry.Index
-			foundMain = true
-			break
-		}
-	}
+	returnCode, err := p.Main()
 
-	if !foundMain {
-		ln.Fatal(ctx, ln.F{"msg": "no main function exported"})
-	}
-
-	returnCode, err := p.vm.ExecCode(int64(mainID))
-	if err != nil {
-		ln.FatalErr(ctx, err)
-	}
-
-	ln.Log(ctx, ln.Info("process returned code"), ln.F{"code": returnCode})
+	ln.Log(ctx, ln.Info("process returned code"), ln.F{"code": returnCode, "type": fmt.Sprintf("%T", returnCode)})
 }
diff --git a/cmd/land/process.go b/cmd/land/process.go
index e27781d..69f6575 100644
--- a/cmd/land/process.go
+++ b/cmd/land/process.go
@@ -114,3 +114,26 @@ func (p *Process) log(ptr int32, len int32) int32 {
 
 	return 0
 }
+
+func (p *Process) Main() (uint32, error) {
+	foundMain := false
+	mainID := uint32(0)
+	for name, entry := range p.mod.Export.Entries {
+		if name == "main" && entry.FieldStr == "main" {
+			mainID = entry.Index
+			foundMain = true
+			break
+		}
+	}
+
+	if !foundMain {
+		return 1, errors.New("no main function found")
+	}
+
+	returnCode, err := p.vm.ExecCode(int64(mainID))
+	if err != nil {
+		return 1, err
+	}
+
+	return returnCode.(uint32), nil
+}
diff --git a/cmd/land/process_test.go b/cmd/land/process_test.go
new file mode 100644
index 0000000..98a3d0b
--- /dev/null
+++ b/cmd/land/process_test.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"os"
+	"testing"
+)
+
+func TestHelloWorld(t *testing.T) {
+	fin, err := os.Open("./testdata/hello.wasm")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer fin.Close()
+
+	p, err := NewProcess(fin)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ret, err := p.Main()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if ret != 0 {
+		t.Fatalf("expected return code to be 0, got: %d", ret)
+	}
+}
diff --git a/cmd/land/testdata/.gitignore b/cmd/land/testdata/.gitignore
new file mode 100644
index 0000000..45d4a47
--- /dev/null
+++ b/cmd/land/testdata/.gitignore
@@ -0,0 +1 @@
+!*.wasm
diff --git a/cmd/land/testdata/hello.wasm b/cmd/land/testdata/hello.wasm
new file mode 100644
index 0000000..1828cc6
Binary files /dev/null and b/cmd/land/testdata/hello.wasm differ