From 52922512e544d9026e3c7b1546cd9aaba84df95f Mon Sep 17 00:00:00 2001
From: Daniel Kang <me@daniel.gs>
Date: Thu, 10 Jan 2019 00:01:02 -0800
Subject: [PATCH] add equality tests

---
 vm/vm_equality_test.go | 50 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 vm/vm_equality_test.go

diff --git a/vm/vm_equality_test.go b/vm/vm_equality_test.go
new file mode 100644
index 0000000..4bb2cf5
--- /dev/null
+++ b/vm/vm_equality_test.go
@@ -0,0 +1,50 @@
+package vm_test
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestEquality(t *testing.T) {
+	testEquality(t, `1`, `1`, true)
+	testEquality(t, `1`, `2`, false)
+
+	testEquality(t, `1.0`, `1.0`, true)
+	testEquality(t, `1.0`, `1.1`, false)
+
+	testEquality(t, `true`, `true`, true)
+	testEquality(t, `true`, `false`, false)
+
+	testEquality(t, `"foo"`, `"foo"`, true)
+	testEquality(t, `"foo"`, `"bar"`, false)
+
+	testEquality(t, `'f'`, `'f'`, true)
+	testEquality(t, `'f'`, `'b'`, false)
+
+	testEquality(t, `[]`, `[]`, true)
+	testEquality(t, `[1]`, `[1]`, true)
+	testEquality(t, `[1]`, `[1, 2]`, false)
+	testEquality(t, `["foo", "bar"]`, `["foo", "bar"]`, true)
+	testEquality(t, `["foo", "bar"]`, `["bar", "foo"]`, false)
+
+	testEquality(t, `{}`, `{}`, true)
+	testEquality(t, `{a: 1, b: 2}`, `{b: 2, a: 1}`, true)
+	testEquality(t, `{a: 1, b: 2}`, `{b: 2}`, false)
+	testEquality(t, `{a: 1, b: {}}`, `{b: {}, a: 1}`, true)
+
+	testEquality(t, `1`, `"foo"`, false)
+	testEquality(t, `1`, `true`, false)
+	testEquality(t, `[1]`, `["1"]`, false)
+	testEquality(t, `[1, [2]]`, `[1, ["2"]]`, false)
+	testEquality(t, `{a: 1}`, `{a: "1"}`, false)
+	testEquality(t, `{a: 1, b: {c: 2}}`, `{a: 1, b: {c: "2"}}`, false)
+}
+
+func testEquality(t *testing.T, lhs, rhs string, expected bool) {
+	// 1. equality is commutative
+	// 2. equality and inequality must be always opposite
+	expect(t, fmt.Sprintf("out = %s == %s", lhs, rhs), expected)
+	expect(t, fmt.Sprintf("out = %s == %s", rhs, lhs), expected)
+	expect(t, fmt.Sprintf("out = %s != %s", lhs, rhs), !expected)
+	expect(t, fmt.Sprintf("out = %s != %s", rhs, lhs), !expected)
+}