Add quickcheck to find broken exports

parser/Cargo.toml

@@ -11,3 +11,6 @@ repository = "https://github.com/chyh1990/yaml-rust"
 [dependencies]
 clippy = { version = "^0.*", optional = true }
 linked-hash-map = ">=0.0.9, <0.4"
+
+[dev-dependencies]
+quickcheck = "0.4"

parser/tests/quickcheck.rs

@@ -0,0 +1,21 @@
+extern crate yaml_rust;
+#[macro_use]
+extern crate quickcheck;
+
+use quickcheck::TestResult;
+use yaml_rust::{Yaml, YamlLoader, YamlEmitter};
+use std::error::Error;
+
+quickcheck! {
+    fn test_check_weird_keys(xs: Vec<String>) -> TestResult {
+        let mut out_str = String::new();
+        {
+            let mut emitter = YamlEmitter::new(&mut out_str);
+            emitter.dump(&Yaml::Array(xs.into_iter().map(|s| Yaml::String(s)).collect())).unwrap();
+        }
+        if let Err(err) = YamlLoader::load_from_str(&out_str) {
+            return TestResult::error(err.description());
+        }
+        return TestResult::passed();
+    }
+}