include more examples (#220)

Author: camshaft

.gitignore

@@ -7,3 +7,5 @@ crash-*
 *.o
 corpus
 crashes
+perf.data*
+*.svg

examples/boolean-tree/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "boolean-tree"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+bolero-generator = { path = "../../lib/bolero-generator" }
+
+[dev-dependencies]
+bolero = { path = "../../lib/bolero" }
+
+[workspace]
+members = ["."]
+
+[profile.fuzz]
+inherits = "dev"
+opt-level = 3
+incremental = false
+codegen-units = 1

examples/boolean-tree/README.md

@@ -0,0 +1,3 @@
+# boolean-tree
+
+A simple boolean logic language

examples/boolean-tree/src/lib.rs

@@ -0,0 +1,38 @@
+use bolero_generator::TypeGenerator;
+
+thread_local! {
+    static SHOULD_PANIC: bool = {
+        #[cfg(bolero_should_panic)]
+        return true;
+
+        #[cfg(not(bolero_should_panic))]
+        return std::env::var("SHOULD_PANIC").is_ok();
+    };
+}
+
+#[cfg(test)]
+mod tests;
+
+#[derive(Clone, Debug, TypeGenerator)]
+pub enum Expr {
+    Value(bool),
+    And(Box<Expr>, Box<Expr>),
+    Or(Box<Expr>, Box<Expr>),
+    Xor(Box<Expr>, Box<Expr>),
+    Nand(Box<Expr>, Box<Expr>),
+    Not(Box<Expr>),
+}
+
+impl Expr {
+    pub fn eval(&self) -> bool {
+        match self {
+            Expr::Value(value) => *value,
+            Expr::And(a, b) => a.eval() && b.eval(),
+            Expr::Or(a, b) => a.eval() || b.eval(),
+            Expr::Xor(a, b) => a.eval() ^ b.eval(),
+            Expr::Nand(a, b) => !(a.eval() && b.eval()),
+            Expr::Not(_) if SHOULD_PANIC.with(|v| *v) => unreachable!(),
+            Expr::Not(a) => !a.eval(),
+        }
+    }
+}

examples/boolean-tree/src/tests.rs

@@ -0,0 +1,12 @@
+use super::*;
+use bolero::check;
+
+#[test]
+fn model_test() {
+    check!()
+        .with_type::<Expr>()
+        .with_max_depth(3)
+        .for_each(|ops| {
+            let _value = ops.eval();
+        })
+}

examples/rle-stack/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "rle-stack"
+version = "0.1.0"
+edition = "2021"
+
+[dev-dependencies]
+bolero = { path = "../../lib/bolero" }
+
+[workspace]
+members = ["."]
+
+[profile.fuzz]
+inherits = "dev"
+opt-level = 3
+incremental = false
+codegen-units = 1

examples/rle-stack/README.md

@@ -0,0 +1,2 @@
+# rle-stack
+A stack which compresses value with run-length encoding

examples/rle-stack/src/lib.rs

@@ -0,0 +1,154 @@
+use core::fmt;
+
+thread_local! {
+    static SHOULD_PANIC: bool = {
+        #[cfg(bolero_should_panic)]
+        return true;
+
+        #[cfg(not(bolero_should_panic))]
+        return std::env::var("SHOULD_PANIC").is_ok();
+    };
+}
+
+type Counter = u16;
+
+//= https://en.wikipedia.org/wiki/Run-length_encoding
+//# Run-length encoding (RLE) is a form of lossless data compression in which
+//# runs of data (sequences in which the same data value occurs in many consecutive
+//# data elements) are stored as a single data value and count, rather than as
+//# the original run.
+
+pub struct RleStack<T> {
+    stack: Vec<Entry<T>>,
+    len: usize,
+}
+
+impl<T> Default for RleStack<T> {
+    fn default() -> Self {
+        Self {
+            stack: vec![],
+            len: 0,
+        }
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for RleStack<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("RleStack")
+            .field("stack", &self.stack)
+            .field("len", &self.len)
+            .finish()
+    }
+}
+
+impl<T: Clone + Eq> RleStack<T> {
+    pub fn push(&mut self, value: T) {
+        self.len += 1;
+
+        if let Some(prev) = self.stack.last_mut() {
+            if prev.merge(&value) {
+                return;
+            }
+        }
+
+        self.stack.push(Entry::new(value));
+    }
+
+    pub fn pop(&mut self) -> Option<T> {
+        let entry = self.stack.last_mut()?;
+
+        self.len -= 1;
+
+        if entry.additional == 0 {
+            return self.stack.pop().map(|entry| entry.value);
+        }
+        entry.additional -= 1;
+        Some(entry.value.clone())
+    }
+
+    pub fn clear(&mut self) {
+        // inject faults into the model if configured
+        if SHOULD_PANIC.with(|v| *v) {
+            return;
+        }
+
+        self.len = 0;
+        self.stack.clear();
+    }
+
+    pub fn len(&self) -> usize {
+        self.len
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.len == 0
+    }
+
+    pub fn iter(&self) -> Iter<T> {
+        Iter {
+            entry: 0,
+            count: 0,
+            stack: self,
+        }
+    }
+}
+
+pub struct Iter<'a, T> {
+    entry: usize,
+    count: Counter,
+    stack: &'a RleStack<T>,
+}
+
+impl<'a, T> Iterator for Iter<'a, T> {
+    type Item = &'a T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let entry = self.stack.stack.get(self.entry)?;
+
+        if entry.additional <= self.count {
+            self.entry += 1;
+            self.count = 0;
+        } else {
+            self.count += 1;
+        }
+
+        Some(&entry.value)
+    }
+}
+
+struct Entry<T> {
+    value: T,
+    additional: Counter,
+}
+
+impl<T: fmt::Debug> fmt::Debug for Entry<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Entry")
+            .field("value", &self.value)
+            .field("additional", &self.additional)
+            .finish()
+    }
+}
+
+impl<T> Entry<T> {
+    pub fn new(value: T) -> Self {
+        Self {
+            value,
+            additional: 0,
+        }
+    }
+}
+
+impl<T: Eq> Entry<T> {
+    pub fn merge(&mut self, other: &T) -> bool {
+        if &self.value == other {
+            self.additional += 1;
+            true
+        } else {
+            false
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests;

examples/rle-stack/src/tests.rs

@@ -0,0 +1,109 @@
+use super::*;
+use bolero::{check, generator::*};
+use core::fmt;
+
+#[derive(Clone, Copy, Debug, TypeGenerator)]
+enum Operation<T> {
+    Push { count: u8, value: T },
+    Pop { count: u8 },
+    Clear,
+}
+
+#[derive(Default)]
+struct Model<T: Copy + fmt::Debug + Eq> {
+    oracle: Vec<T>,
+    subject: RleStack<T>,
+}
+
+impl<T: Copy + fmt::Debug + Eq> Model<T> {
+    pub fn push(&mut self, value: T) {
+        self.oracle.push(value);
+        self.subject.push(value);
+        self.invariants();
+    }
+
+    pub fn pop(&mut self) -> Option<T> {
+        let expected = self.oracle.pop();
+        let actual = self.subject.pop();
+        assert_eq!(expected, actual);
+        self.invariants();
+        actual
+    }
+
+    pub fn clear(&mut self) {
+        self.oracle.clear();
+        self.subject.clear();
+        self.invariants();
+    }
+
+    pub fn apply(&mut self, operation: Operation<T>) {
+        match operation {
+            Operation::Push { count, value } => {
+                for _ in 0..count {
+                    self.push(value);
+                }
+            }
+            Operation::Pop { count } => {
+                for _ in 0..count {
+                    self.pop();
+                }
+            }
+            Operation::Clear => {
+                self.clear();
+            }
+        }
+    }
+
+    pub fn finish(&self) {
+        self.invariants();
+        let actual: Vec<_> = self.subject.iter().copied().collect();
+        assert_eq!(
+            self.oracle, actual,
+            "\n\nSubject state: {:#?}",
+            self.subject
+        );
+    }
+
+    fn invariants(&self) {
+        assert_eq!(
+            self.oracle.len(),
+            self.subject.len(),
+            "lengths do not match"
+        );
+        assert_eq!(
+            self.oracle.is_empty(),
+            self.subject.is_empty(),
+            "is_empty does not match"
+        );
+    }
+}
+
+impl<T: Copy + fmt::Debug + Eq> Drop for Model<T> {
+    fn drop(&mut self) {
+        if !std::thread::panicking() {
+            self.finish();
+        }
+    }
+}
+
+#[test]
+fn model_test() {
+    check!().with_type::<Vec<Operation<u8>>>().for_each(|ops| {
+        let mut model = Model::default();
+        for op in ops {
+            model.apply(*op);
+        }
+    })
+}
+
+#[test]
+fn unit_test() {
+    let mut model = <Model<u8>>::default();
+
+    assert!(model.pop().is_none());
+    model.clear();
+    assert!(model.pop().is_none());
+
+    model.push(123);
+    assert_eq!(model.pop(), Some(123));
+}