1 files changed, 88 insertions, 0 deletions
diff --git a/src/syntax/test.rs b/src/syntax/test.rs
new file mode 100644
index 00000000..e37e8cf5
--- /dev/null
+++ b/src/syntax/test.rs
@@ -0,0 +1,88 @@
+use super::func::FuncHeader;
+use super::expr::{Expr, Tuple, Object};
+use super::*;
+
+
+function! {
+    /// Most functions in the tests are parsed into the debug function for easy
+    /// inspection of arguments and body.
+    #[derive(Debug, Clone, PartialEq)]
+    pub struct DebugFn {
+        pub header: FuncHeader,
+        pub body: Option<SyntaxModel>,
+    }
+
+    parse(header, body, ctx, errors, decos) {
+        let cloned = header.clone();
+        header.args.pos.items.clear();
+        header.args.key.pairs.clear();
+        DebugFn {
+            header: cloned,
+            body: body!(opt: body, ctx, errors, decos),
+        }
+    }
+
+    layout(self, ctx, errors) { vec![] }
+}
+
+/// Compares elements by only looking at values and ignoring spans.
+pub trait SpanlessEq<Rhs=Self> {
+    fn spanless_eq(&self, other: &Rhs) -> bool;
+}
+
+impl SpanlessEq for Vec<Spanned<Token<'_>>> {
+    fn spanless_eq(&self, other: &Vec<Spanned<Token>>) -> bool {
+        self.len() == other.len()
+        && self.iter().zip(other).all(|(x, y)| x.v == y.v)
+    }
+}
+
+impl SpanlessEq for SyntaxModel {
+    fn spanless_eq(&self, other: &SyntaxModel) -> bool {
+        fn downcast<'a>(func: &'a (dyn Model + 'static)) -> &'a DebugFn {
+            func.downcast::<DebugFn>().expect("not a debug fn")
+        }
+
+        self.nodes.len() == other.nodes.len()
+        && self.nodes.iter().zip(&other.nodes).all(|(x, y)| match (&x.v, &y.v) {
+            (Node::Model(a), Node::Model(b)) => {
+                downcast(a.as_ref()).spanless_eq(downcast(b.as_ref()))
+            }
+            (a, b) => a == b,
+        })
+    }
+}
+
+impl SpanlessEq for DebugFn {
+    fn spanless_eq(&self, other: &DebugFn) -> bool {
+        self.header.name.v == other.header.name.v
+        && self.header.args.pos.spanless_eq(&other.header.args.pos)
+        && self.header.args.key.spanless_eq(&other.header.args.key)
+    }
+}
+
+impl SpanlessEq for Expr {
+    fn spanless_eq(&self, other: &Expr) -> bool {
+        match (self, other) {
+            (Expr::Tuple(a), Expr::Tuple(b)) => a.spanless_eq(b),
+            (Expr::Object(a), Expr::Object(b)) => a.spanless_eq(b),
+            (a, b) => a == b,
+        }
+    }
+}
+
+impl SpanlessEq for Tuple {
+    fn spanless_eq(&self, other: &Tuple) -> bool {
+        self.items.len() == other.items.len()
+        && self.items.iter().zip(&other.items)
+            .all(|(x, y)| x.v.spanless_eq(&y.v))
+    }
+}
+
+impl SpanlessEq for Object {
+    fn spanless_eq(&self, other: &Object) -> bool {
+        self.pairs.len() == other.pairs.len()
+        && self.pairs.iter().zip(&other.pairs)
+            .all(|(x, y)| x.key.v == y.key.v && x.value.v.spanless_eq(&y.value.v))
+    }
+}