fuzz: add compile_taproot fuzztest

Author: apoelstra

.github/workflows/cron-daily-fuzz.yml

@@ -19,6 +19,7 @@ jobs:
         # over that limit with fuzzing because of the hour run time.
         fuzz_target: [
 compile_descriptor,
+compile_taproot,
 parse_descriptor,
 parse_descriptor_secret,
 roundtrip_concrete,

fuzz/Cargo.toml

@@ -19,6 +19,10 @@ regex = "1.0"
 name = "compile_descriptor"
 path = "fuzz_targets/compile_descriptor.rs"
 
+[[bin]]
+name = "compile_taproot"
+path = "fuzz_targets/compile_taproot.rs"
+
 [[bin]]
 name = "parse_descriptor"
 path = "fuzz_targets/parse_descriptor.rs"

fuzz/fuzz_targets/compile_taproot.rs

@@ -0,0 +1,37 @@
+#![allow(unexpected_cfgs)]
+
+use std::str::FromStr;
+
+use honggfuzz::fuzz;
+use miniscript::{policy, Miniscript, Tap};
+use policy::Liftable;
+
+type Script = Miniscript<String, Tap>;
+type Policy = policy::Concrete<String>;
+
+fn do_test(data: &[u8]) {
+    let data_str = String::from_utf8_lossy(data);
+    if let Ok(pol) = Policy::from_str(&data_str) {
+        // Compile
+        if let Ok(desc) = pol.compile::<Tap>() {
+            // Lift
+            assert_eq!(desc.lift().unwrap().sorted(), pol.lift().unwrap().sorted());
+            // Try to roundtrip the output of the compiler
+            let output = desc.to_string();
+            if let Ok(desc) = Script::from_str(&output) {
+                let rtt = desc.to_string();
+                assert_eq!(output.to_lowercase(), rtt.to_lowercase());
+            } else {
+                panic!("compiler output something unparseable: {}", output)
+            }
+        }
+    }
+}
+
+fn main() {
+    loop {
+        fuzz!(|data| {
+            do_test(data);
+        });
+    }
+}

fuzz/generate-files.sh

@@ -22,7 +22,7 @@ publish = false
 cargo-fuzz = true
 
 [dependencies]
-honggfuzz = { version = "0.5.55", default-features = false }
+honggfuzz = { version = "0.5.56", default-features = false }
 miniscript = { path = "..", features = [ "compiler" ] }
 
 regex = "1.0"