From a76b47b7bab7c4da6a99d4c19703d3603bf8ef14 Mon Sep 17 00:00:00 2001
From: Andrea Manzini <ilmanzo@gmail.com>
Date: Sat, 16 May 2020 11:34:41 +0200
Subject: [PATCH] refactor with table driven tests

---
 wasm/vm_num_test.go | 58 ++++++++++++++++++++++++---------------------
 1 file changed, 31 insertions(+), 27 deletions(-)

diff --git a/wasm/vm_num_test.go b/wasm/vm_num_test.go
index 9bd53527..d09fdf99 100644
--- a/wasm/vm_num_test.go
+++ b/wasm/vm_num_test.go
@@ -1,40 +1,44 @@
 package wasm
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
-func buildvm() *VirtualMachine {
-	return &VirtualMachine{
-		OperandStack: NewVirtualMachineOperandStack(),
+func TestNumOps(t *testing.T) {
+
+	var testTable = []struct {
+		input [2]int                // numbers to push on the stack
+		op    func(*VirtualMachine) // operation to apply
+		desc  string                // string description of the operation
+		want  uint32                // result should obtain
+	}{
+		{input: [2]int{0, 0}, op: i32eqz, desc: "i32eqz", want: 1},
+		{input: [2]int{3, 3}, op: i32eq, desc: "i32eq", want: 1},
+		{input: [2]int{3, 4}, op: i32ne, desc: "i32ne", want: 1},
+		{input: [2]int{3, 3}, op: i32ne, desc: "i32ne", want: 0},
+		{input: [2]int{-4, 1}, op: i32lts, desc: "i32lts", want: 1},
+		{input: [2]int{4, -1}, op: i32lts, desc: "i32lts", want: 0},
+		{input: [2]int{1, 4}, op: i32ltu, desc: "i32ltu", want: 1},
+		{input: [2]int{4, 1}, op: i32ltu, desc: "i32ltu", want: 0},
+		{input: [2]int{1, -4}, op: i32gts, desc: "i32gts", want: 1},
+		{input: [2]int{-4, 1}, op: i32gts, desc: "i32gts", want: 0},
 	}
-}
 
-func Test_i32eqz(t *testing.T) {
-	vm := buildvm()
-	vm.OperandStack.Push(uint64(0))
-	i32eqz(vm)
-	assert.Equal(t, uint32(1), uint32(vm.OperandStack.Pop()))
-}
+	var vm VirtualMachine
+	for id, tt := range testTable {
+		vm = VirtualMachine{
+			OperandStack: NewVirtualMachineOperandStack(),
+		}
 
-func Test_i32eq(t *testing.T) {
-	vm := buildvm()
-	vm.OperandStack.Push(uint64(3))
-	vm.OperandStack.Push(uint64(3))
-	i32eq(vm)
-	assert.Equal(t, uint32(1), uint32(vm.OperandStack.Pop()))
-}
+		vm.OperandStack.Push(uint64(tt.input[0]))
+		vm.OperandStack.Push(uint64(tt.input[1]))
+		tt.op(&vm)
+
+		assert.Equal(t, tt.want, uint32(vm.OperandStack.Pop()),
+			fmt.Sprintf("test #%d : %d %s %d should eq %d", id, tt.input[0], tt.desc, tt.input[1], tt.want))
+	}
 
-func Test_i32ne(t *testing.T) {
-	vm := buildvm()
-	vm.OperandStack.Push(uint64(3))
-	vm.OperandStack.Push(uint64(4))
-	i32ne(vm)
-	assert.Equal(t, uint32(1), uint32(vm.OperandStack.Pop()))
-	vm.OperandStack.Push(uint64(3))
-	vm.OperandStack.Push(uint64(3))
-	i32ne(vm)
-	assert.Equal(t, uint32(0), uint32(vm.OperandStack.Pop()))
 }