From 12bde12b2e18c8b82b1510ac4305de66d1205e1a Mon Sep 17 00:00:00 2001
From: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Date: Fri, 25 Sep 2026 11:05:35 +0800
Subject: Add tests

---
 .../java/com/seaofnodes/simple/Chapter04Test.java  | 28 ++++++++++++++++++++++
 1 file changed, 28 insertions(+)

(limited to 'chapter22/src')

diff --git a/chapter22/src/test/java/com/seaofnodes/simple/Chapter04Test.java b/chapter22/src/test/java/com/seaofnodes/simple/Chapter04Test.java
index c6199193..e5a16680 100644
--- a/chapter22/src/test/java/com/seaofnodes/simple/Chapter04Test.java
+++ b/chapter22/src/test/java/com/seaofnodes/simple/Chapter04Test.java
@@ -52,6 +52,34 @@ public class Chapter04Test {
         assertEquals("return arg;", code.print());
     }
 
+    @Test
+    public void testSub0() {
+        CodeGen code = new CodeGen("return arg-0;");
+        code.parse();
+        assertEquals("return arg;", code.print());
+    }
+
+    @Test
+    public void test0Sub() {
+        CodeGen code = new CodeGen("return 0-arg;");
+        code.parse();
+        assertEquals("return (-arg);", code.print());
+    }
+
+    @Test
+    public void testSubNeg() {
+        CodeGen code = new CodeGen("return 3--arg;");
+        code.parse();
+        assertEquals("return (arg+3);", code.print());
+    }
+
+    @Test
+    public void testNegSub() {
+        CodeGen code = new CodeGen("return -arg-3;");
+        code.parse();
+        assertEquals("return (-(arg+3));", code.print());
+    }
+
     @Test
     public void testVarArg() {
         CodeGen code = new CodeGen("return arg; ");
-- 
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