add some more tests for arithmetic expressions

crates/tests/test-data/arithmetic.sh

@@ -0,0 +1,52 @@
+# Test basic arithmetic
+> echo $((2 + 5))
+7
+
+> echo $((10 - 3))
+7
+
+> echo $((3 * 4))
+12
+
+> echo $((15 / 3))
+5
+
+# Test operator precedence
+> echo $((2 + 3 * 4))
+14
+
+# Fails
+# > echo $(((2 + 3) * 4))
+# 20
+
+# Test with variables
+> export NUM=5
+> echo $((NUM + 3))
+8
+
+> export A=2
+> export B=3
+> echo $((A * B + 1))
+7
+
+# # Test increment/decrement NOT IMPLEMENTED YET!
+# > export COUNT=1
+# > echo $((COUNT++))
+# 1
+# > echo $COUNT
+# 2
+
+# > export X=5
+# > echo $((--X))
+# 4
+
+# Test complex expressions
+> export BASE=2
+> echo $((BASE ** 3 + 1))
+9
+
+# Test division and modulo
+> echo $((10 / 3))
+3
+> echo $((10 % 3))
+1