fix(vm): add doesnt_crash baseline test

Cargo.lock

@@ -102,6 +102,7 @@ version = "0.0.0"
 dependencies = [
  "fogtix-bytecode",
  "once_cell",
+ "proptest",
  "tracing",
 ]
 

crates/fogtix-vm/Cargo.toml

@@ -14,3 +14,10 @@ features = ["std"]
 
 [dependencies.once_cell]
 version = "1.15"
+
+[dev-dependencies]
+
+[dev-dependencies.proptest]
+version = "1.0"
+default-features = false
+features = ["alloc"]

crates/fogtix-vm/src/lib.rs

@@ -66,6 +66,7 @@ pub struct Process {
     pub stack: Vec<StackEntValue>,
     pub callstack: Vec<InstrPtr>,
     pub instrp: InstrPtr,
+    pub fuel: Option<u64>,
 }
 
 impl Process {
@@ -74,6 +75,7 @@ impl Process {
             stack: Vec::new(),
             callstack: Vec::new(),
             instrp,
+            fuel: None,
         }
     }
 
@@ -101,6 +103,13 @@ impl Process {
             use fogtix_bytecode::consts::MathBinOp;
             let previptr = self.instrp.pos;
             tracing::trace!("previptr = {}", previptr);
+            if let Some(ref mut x) = &mut self.fuel {
+                if *x == 0 {
+                    tracing::info!("out of fuel");
+                    break;
+                }
+                *x -= 1;
+            }
             let (nxtidelta, nxti) = match next_instr(&self.instrp.m, self.instrp.pos) {
                 None => {
                     tracing::error!(
@@ -358,3 +367,23 @@ impl Process {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    proptest::proptest! {
+        #![proptest_config(proptest::prelude::ProptestConfig::with_cases(4096))]
+
+        #[test]
+        fn doesnt_crash(inp in proptest::collection::vec(0..=u8::MAX, 0..1024)) {
+            let inp: Arc<Vec<u8>> = Arc::new(inp);
+            let module: Module = inp;
+            let mut p = Process::new(InstrPtr {
+                m: module,
+                pos: 0,
+            });
+            p.fuel = Some(1024);
+            p.run();
+        }
+    }
+}