1 files changed, 51 insertions, 0 deletions
diff --git a/vendor/proptest/examples/fib.rs b/vendor/proptest/examples/fib.rs
new file mode 100644
index 000000000..f2d440853
--- /dev/null
+++ b/vendor/proptest/examples/fib.rs
@@ -0,0 +1,51 @@
+//-
+// Copyright 2018 Jason Lingle
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// This #[cfg] is only here so that CI can test building proptest with the
+// timeout feature disabled. You do not need it in your code.
+#[cfg(feature = "timeout")]
+mod fib {
+    use proptest::prelude::*;
+
+    // The worst possible way to calculate Fibonacci numbers
+    fn fib(n: u64) -> u64 {
+        if n <= 1 {
+            n
+        } else {
+            fib(n - 1) + fib(n - 2)
+        }
+    }
+
+    proptest! {
+        #![proptest_config(ProptestConfig {
+            // Setting both fork and timeout is redundant since timeout implies
+            // fork, but both are shown for clarity.
+            fork: true,
+            timeout: 1000,
+            .. ProptestConfig::default()
+        })]
+
+        // NB We omit #[test] on the test function so that main() can call it.
+        fn test_fib(n in prop::num::u64::ANY) {
+            // For large n, this will variously run for an extremely long time,
+            // overflow the stack, or panic due to integer overflow.
+            assert!(fib(n) >= n);
+        }
+    }
+
+    // This is just here so that main can call it
+    pub fn do_test_fib() {
+        test_fib();
+    }
+}
+
+fn main() {
+    #[cfg(feature = "timeout")]
+    fib::do_test_fib();
+}