Add binary-decode tests

2 files changed, 53 insertions, 1 deletions

diff --git a/dhall/src/phase/binary.rs b/dhall/src/phase/binary.rs
index bfe217f..cab3c8e 100644
--- a/dhall/src/phase/binary.rs
+++ b/dhall/src/phase/binary.rs
@@ -48,10 +48,21 @@ fn cbor_value_to_dhall(
         Bool(b) => BoolLit(*b),
         Array(vec) => match vec.as_slice() {
             [String(l), U64(n)] => {
+                if l.as_str() == "_" {
+                    Err(DecodeError::WrongFormatError(
+                        "`_` variable was encoded incorrectly".to_owned(),
+                    ))?
+                }
                 let l = Label::from(l.as_str());
                 Var(V(l, *n as usize))
             }
             [U64(0), f, args..] => {
+                if args.is_empty() {
+                    Err(DecodeError::WrongFormatError(
+                        "Function application must have at least one argument"
+                            .to_owned(),
+                    ))?
+                }
                 let mut f = cbor_value_to_dhall(&f)?;
                 for a in args {
                     let a = cbor_value_to_dhall(&a)?;
@@ -65,6 +76,11 @@ fn cbor_value_to_dhall(
                 Lam(Label::from("_"), x, y)
             }
             [U64(1), String(l), x, y] => {
+                if l.as_str() == "_" {
+                    Err(DecodeError::WrongFormatError(
+                        "`_` variable was encoded incorrectly".to_owned(),
+                    ))?
+                }
                 let x = cbor_value_to_dhall(&x)?;
                 let y = cbor_value_to_dhall(&y)?;
                 let l = Label::from(l.as_str());
@@ -76,6 +92,11 @@ fn cbor_value_to_dhall(
                 Pi(Label::from("_"), x, y)
             }
             [U64(2), String(l), x, y] => {
+                if l.as_str() == "_" {
+                    Err(DecodeError::WrongFormatError(
+                        "`_` variable was encoded incorrectly".to_owned(),
+                    ))?
+                }
                 let x = cbor_value_to_dhall(&x)?;
                 let y = cbor_value_to_dhall(&y)?;
                 let l = Label::from(l.as_str());
diff --git a/dhall/src/tests.rs b/dhall/src/tests.rs
index 8b32fb4..da48d15 100644
--- a/dhall/src/tests.rs
+++ b/dhall/src/tests.rs
@@ -45,6 +45,7 @@ pub enum Feature {
     Parser,
     Printer,
     BinaryEncoding,
+    BinaryDecoding,
     Import,
     Normalization,
     AlphaNormalization,
@@ -84,6 +85,7 @@ pub fn run_test(
         Parser => "parser/",
         Printer => "parser/",
         BinaryEncoding => "parser/",
+        BinaryDecoding => "binary-decode/",
         Import => "import/",
         Normalization => "normalization/",
         AlphaNormalization => "alpha-normalization/",
@@ -94,6 +96,24 @@ pub fn run_test(
         "../dhall-lang/tests/".to_owned() + feature_prefix + base_path;
     match status {
         Success => {
+            match feature {
+                BinaryDecoding => {
+                    let expr_file_path = base_path.clone() + "A.dhallb";
+                    let expr_file_path = PathBuf::from(&expr_file_path);
+                    let mut expr_data = Vec::new();
+                    {
+                        File::open(&expr_file_path)?
+                            .read_to_end(&mut expr_data)?;
+                    }
+                    let expr = Parsed::parse_binary(&expr_data)?;
+                    let expected_file_path = base_path + "B.dhall";
+                    let expected = parse_file_str(&expected_file_path)?;
+                    assert_eq_pretty!(expr, expected);
+
+                    return Ok(());
+                }
+                _ => {}
+            }
             let expr_file_path = base_path.clone() + "A.dhall";
             let expr = parse_file_str(&expr_file_path)?;
 
@@ -164,7 +184,9 @@ pub fn run_test(
                 .normalize();
 
             match feature {
-                Parser | Printer | BinaryEncoding => unreachable!(),
+                Parser | Printer | BinaryEncoding | BinaryDecoding => {
+                    unreachable!()
+                }
                 Import => {
                     let expr = expr.skip_typecheck().normalize();
                     assert_eq_display!(expr, expected);
@@ -201,6 +223,15 @@ pub fn run_test(
                     }
                 }
                 Printer | BinaryEncoding => unreachable!(),
+                BinaryDecoding => {
+                    let expr_file_path = file_path + "b";
+                    let mut expr_data = Vec::new();
+                    {
+                        File::open(&PathBuf::from(&expr_file_path))?
+                            .read_to_end(&mut expr_data)?;
+                    }
+                    Parsed::parse_binary(&expr_data).unwrap_err();
+                }
                 Import => {
                     parse_file_str(&file_path)?.resolve().unwrap_err();
                 }