test(tazjin/rlox): Add some tests for numerical operations r/2250

If I was adding any dependencies, this might be a good one for a
property-based test thing, but I'm not going to.

Change-Id: Ia801d041479d1a88c59ef9e0fe1460b3640382e3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2569
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI

2 files changed, 51 insertions, 0 deletions

diff --git a/users/tazjin/rlox/src/bytecode/mod.rs b/users/tazjin/rlox/src/bytecode/mod.rs
index 0776225bec91..3c7dad97be3e 100644
--- a/users/tazjin/rlox/src/bytecode/mod.rs
+++ b/users/tazjin/rlox/src/bytecode/mod.rs
@@ -9,6 +9,9 @@ mod opcode;
 mod value;
 mod vm;
 
+#[cfg(test)]
+mod tests;
+
 use chunk::Chunk;
 pub struct Interpreter {}
 
diff --git a/users/tazjin/rlox/src/bytecode/tests.rs b/users/tazjin/rlox/src/bytecode/tests.rs
new file mode 100644
index 000000000000..543d9cab515d
--- /dev/null
+++ b/users/tazjin/rlox/src/bytecode/tests.rs
@@ -0,0 +1,48 @@
+use super::*;
+
+use crate::Lox;
+
+fn expect(code: &str, value: value::Value) {
+    let result = Interpreter::create()
+        .interpret(code.into())
+        .expect("evaluation failed");
+    assert_eq!(result, value);
+}
+
+#[test]
+fn numbers() {
+    expect("1", 1.0);
+    expect("13.37", 13.37);
+}
+
+#[test]
+fn negative_numbers() {
+    // Note: This technically tests unary operators.
+    expect("-1", -1.0);
+    expect("-13.37", -13.37);
+}
+
+#[test]
+fn terms() {
+    expect("1 + 2", 3.0);
+    expect("3 - 1", 2.0);
+    expect("0.7 + 0.3", 1.0);
+    expect("1 + -3", -2.0);
+    expect("-1 - -1", 0.0);
+    expect("10 - -10 + 10", 30.0);
+}
+
+#[test]
+fn factors() {
+    expect("1 * 2", 2.0);
+    expect("10 / 5", 2.0);
+    expect("0.7 * 4 / 1.4", 2.0);
+    expect("10 * -10 / 10", -10.0);
+}
+
+#[test]
+fn arithmetic() {
+    expect("10 - 3 * 2", 4.0);
+    expect("-4 * -4 + (14 - 5)", 25.0);
+    expect("(702 + 408) - ((239 - 734) / -5) + -4", 1007.0);
+}