Get a failing specialize_expr test

crates/compiler/can/Cargo.toml

@@ -28,3 +28,4 @@ static_assertions.workspace = true
 indoc.workspace = true
 insta.workspace = true
 pretty_assertions.workspace = true
+test_compile.workspace = true

crates/compiler/can/src/annotation.rs

@@ -130,7 +130,7 @@ pub struct AbleVariable {
     pub first_seen: Region,
 }
 
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, PartialEq)]
 pub struct IntroducedVariables {
     pub wildcards: Vec<Loc<Variable>>,
     pub lambda_sets: Vec<Variable>,

crates/compiler/can/src/def.rs

@@ -62,7 +62,7 @@ use std::io::Read;
 use std::path::PathBuf;
 use std::sync::Arc;
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Def {
     pub loc_pattern: Loc<Pattern>,
     pub loc_expr: Loc<Expr>,
@@ -89,7 +89,7 @@ impl Def {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Annotation {
     pub signature: Type,
     pub introduced_variables: IntroducedVariables,

crates/compiler/can/src/expected.rs

@@ -2,7 +2,7 @@ use crate::pattern::Pattern;
 use roc_region::all::{Loc, Region};
 use roc_types::types::{AnnotationSource, PReason, Reason};
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Expected<T> {
     NoExpectation(T),
     FromAnnotation(Loc<Pattern>, usize, AnnotationSource, T),
@@ -10,7 +10,7 @@ pub enum Expected<T> {
 }
 
 /// Like Expected, but for Patterns.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum PExpected<T> {
     NoExpectation(T),
     ForReason(PReason, T, Region),

crates/compiler/can/src/expr.rs

@@ -132,7 +132,7 @@ impl IntValue {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum Expr {
     // Literals
 
@@ -341,7 +341,7 @@ pub enum Expr {
     RuntimeError(RuntimeError),
 }
 
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub struct ExpectLookup {
     pub symbol: Symbol,
     pub var: Variable,
@@ -419,7 +419,7 @@ impl Expr {
 
 /// Stores exhaustiveness-checking metadata for a closure argument that may
 /// have an annotated type.
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub struct AnnotatedMark {
     pub annotation_var: Variable,
     pub exhaustive: ExhaustiveMark,
@@ -443,7 +443,7 @@ impl AnnotatedMark {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct ClosureData {
     pub function_type: Variable,
     pub closure_type: Variable,
@@ -536,7 +536,7 @@ impl StructAccessorData {
 /// An opaque wrapper like `@Foo`, which is equivalent to `\p -> @Foo p`
 /// These are desugared to closures, but we distinguish them so we can have
 /// better error messages during constraint generation.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct OpaqueWrapFunctionData {
     pub opaque_name: Symbol,
     pub opaque_var: Variable,
@@ -606,7 +606,7 @@ impl OpaqueWrapFunctionData {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct Field {
     pub var: Variable,
     // The region of the full `foo: f bar`, rather than just `f bar`
@@ -630,7 +630,7 @@ impl Recursive {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct WhenBranchPattern {
     pub pattern: Loc<Pattern>,
     /// Degenerate branch patterns are those that don't fully bind symbols that the branch body
@@ -639,7 +639,7 @@ pub struct WhenBranchPattern {
     pub degenerate: bool,
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct WhenBranch {
     pub patterns: Vec<WhenBranchPattern>,
     pub value: Loc<Expr>,

crates/compiler/can/src/pattern.rs

@@ -19,7 +19,7 @@ use roc_types::types::{LambdaSet, OptAbleVar, PatternCategory, Type};
 
 /// A pattern, including possible problems (e.g. shadowing) so that
 /// codegen can generate a runtime error if this pattern is reached.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum Pattern {
     Identifier(Symbol),
     As(Box<Loc<Pattern>>, Symbol),
@@ -198,7 +198,7 @@ impl Pattern {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct ListPatterns {
     pub patterns: Vec<Loc<Pattern>>,
     /// Where a rest pattern splits patterns before and after it, if it does at all.
@@ -229,7 +229,7 @@ impl ListPatterns {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct RecordDestruct {
     pub var: Variable,
     pub label: Lowercase,
@@ -237,14 +237,14 @@ pub struct RecordDestruct {
     pub typ: DestructType,
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub struct TupleDestruct {
     pub var: Variable,
     pub destruct_index: usize,
     pub typ: (Variable, Loc<Pattern>),
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum DestructType {
     Required,
     Optional(Variable, Loc<Expr>),

crates/compiler/can/tests/test_can_expr.rs

@@ -0,0 +1,13 @@
+#[cfg(test)]
+mod test_can_expr {
+    use roc_can::expr::Expr;
+    use test_compile::can_expr;
+
+    #[test]
+    fn test_can_unit() {
+        let output = can_expr("{}");
+
+        assert_eq!(output.problems, Vec::new());
+        assert!(matches!(output.expr, Expr::EmptyRecord));
+    }
+}