WIP roll our own fuzz

rust-lang · Jul 4, 2024 · 1c2b0a3 · 1c2b0a3
1 parent b83b946
commit 1c2b0a3
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Showing 9 changed files with 749 additions and 234 deletions.
diff --git a/crates/formality-core/src/binder/fuzz.rs b/crates/formality-core/src/binder/fuzz.rs
@@ -1,6 +1,4 @@
-use bolero::{TypeGenerator, ValueGenerator};
-
-use crate::{fold::CoreFold, fuzz::PushGuard, language::Language, variable::CoreBoundVar};
+use crate::{fold::CoreFold, fuzz::Fuzzable, language::Language, variable::CoreBoundVar};
 
 use super::{fresh_bound_var, CoreBinder};
 
@@ -9,16 +7,24 @@ pub struct KindVec<L: Language> {
     pub vec: Vec<L::Kind>,
 }
 
-impl<L: Language> bolero::TypeGenerator for KindVec<L>
+impl<L: Language> Fuzzable for KindVec<L>
 where
-    L::Kind: TypeGenerator,
+    L::Kind: Fuzzable,
 {
-    fn generate<D: bolero::Driver>(driver: &mut D) -> Option<Self> {
-        let num_kinds: usize = L::fuzz_binder_range().get().generate(driver)?;
-        Some(KindVec {
-            vec: (0..num_kinds)
-                .map(|_| driver.gen())
-                .collect::<Option<_>>()?,
+    fn estimate_cardinality(cx: &mut crate::fuzz::FuzzCx) -> f64 {
+        cx.enter_estimate_cardinality::<Self>(|guard| {
+            guard.binder_range().len() as f64 * guard.estimate_cardinality::<L::Kind>()
+        })
+    }
+
+    fn fuzz(cx: &mut crate::fuzz::FuzzCx) -> Option<Self> {
+        cx.enter_fuzz::<Self>(|guard| {
+            let binder_range = guard.binder_range().clone();
+            let len = guard.fuzz_usize(binder_range)?;
+            let vec = (0..len)
+                .map(|_| guard.fuzz::<L::Kind>())
+                .collect::<Option<_>>()?;
+            Some(KindVec { vec })
         })
     }
 }
@@ -66,16 +72,22 @@ impl<L: Language> PushKindGuard<L> {
     }
 }
 
-impl<L: Language, T> bolero::TypeGenerator for CoreBinder<L, T>
+impl<L: Language, T> Fuzzable for CoreBinder<L, T>
 where
-    T: bolero::TypeGenerator + CoreFold<L>,
-    L::Kind: bolero::TypeGenerator,
+    T: Fuzzable + CoreFold<L>,
 {
-    /// Generate a binder with some fresh data inside.
-    fn generate<D: bolero::Driver>(driver: &mut D) -> Option<Self> {
-        let kinds: KindVec<L> = driver.gen()?;
-        let guard = L::open_fuzz_binder(&kinds.vec);
-        let bound_term: T = driver.gen()?;
-        Some(guard.into_binder(bound_term))
+    fn estimate_cardinality(cx: &mut crate::fuzz::FuzzCx) -> f64 {
+        cx.enter_estimate_cardinality::<Self>(|guard| {
+            guard.estimate_cardinality::<KindVec<L>>() * guard.estimate_cardinality::<T>()
+        })
+    }
+
+    fn fuzz(cx: &mut crate::fuzz::FuzzCx) -> Option<Self> {
+        cx.enter_fuzz::<Self>(|guard| {
+            let kinds = guard.fuzz::<KindVec<L>>()?;
+            let guard = L::open_fuzz_binder(&kinds.vec);
+            let bound_term = guard.fuzz::<T>()?;
+            Some(guard.into_binder(bound_term))
+        })
     }
 }