Added consteval tests

Author: OleStrohm

crates/hir-def/src/body.rs

@@ -28,8 +28,8 @@ use crate::{
     nameres::DefMap,
     path::{ModPath, Path},
     src::{HasChildSource, HasSource},
-    AsMacroCall, BlockId, DefWithBodyId, HasModule, LocalModuleId, Lookup, MacroId,
-    ModuleId, UnresolvedMacro,
+    AsMacroCall, BlockId, DefWithBodyId, HasModule, LocalModuleId, Lookup, MacroId, ModuleId,
+    UnresolvedMacro,
 };
 
 pub use lower::LowerCtx;
@@ -328,7 +328,6 @@ impl Body {
                 let e = v.parent.lookup(db);
                 let src = v.parent.child_source(db);
                 let variant = &src.value[v.local_id];
-                // TODO(ole): Handle missing exprs (+1 to the prev)
                 (src.file_id, e.container, variant.expr())
             }
         };

crates/hir-ty/src/consteval.rs

@@ -203,7 +203,7 @@ pub fn eval_const(
                 Ok(ComputedExpr::Enum(
                     get_name(variant, ctx),
                     variant,
-                    Literal::Int(value + 1, Some(BuiltinInt::I128)),
+                    Literal::Int(value, Some(BuiltinInt::I128)),
                 ))
             }
             _ => Err(ConstEvalError::IncompleteExpr),

crates/hir-ty/src/consteval/tests.rs

@@ -87,6 +87,35 @@ fn consts() {
     );
 }
 
+#[test]
+fn enums() {
+    check_number(
+        r#"
+    enum E {
+        F1 = 1,
+        F2 = 2 * E::F1 as u8,
+        F3 = 3 * E::F2 as u8,
+    }
+    const GOAL: i32 = E::F3 as u8;
+    "#,
+        6,
+    );
+    let r = eval_goal(
+        r#"
+        enum E { A = 1, }
+        const GOAL: E = E::A;
+        "#,
+    )
+    .unwrap();
+    match r {
+        ComputedExpr::Enum(name, _, Literal::Uint(val, _)) => {
+            assert_eq!(name, "E::A");
+            assert_eq!(val, 1);
+        }
+        x => panic!("Expected enum but found {:?}", x),
+    }
+}
+
 #[test]
 fn const_loop() {
     check_fail(

crates/hir/src/lib.rs

@@ -952,6 +952,10 @@ impl Enum {
     pub fn ty(self, db: &dyn HirDatabase) -> Type {
         Type::from_def(db, self.id)
     }
+
+    pub fn is_data_carrying(self, db: &dyn HirDatabase) -> bool {
+        self.variants(db).iter().all(|v| matches!(v.kind(db), StructKind::Unit))
+    }
 }
 
 impl HasVisibility for Enum {
@@ -996,7 +1000,6 @@ impl Variant {
     }
 
     pub fn value(self, db: &dyn HirDatabase) -> Option<Expr> {
-        // TODO(ole): Handle missing exprs (+1 to the prev)
         self.source(db)?.value.expr()
     }
 

crates/ide/src/hover/render.rs

@@ -348,12 +348,15 @@ pub(super) fn definition(
         Definition::Module(it) => label_and_docs(db, it),
         Definition::Function(it) => label_and_docs(db, it),
         Definition::Adt(it) => label_and_docs(db, it),
-        Definition::Variant(it) => label_value_and_docs(db, it, |&it| match it.kind(db) {
-            StructKind::Unit => match it.eval(db) {
-                Ok(x) => Some(format!("{}", x.enum_value().unwrap_or(x))),
-                Err(_) => it.value(db).map(|x| format!("{:?}", x)),
-            },
-            _ => None,
+        Definition::Variant(it) => label_value_and_docs(db, it, |&it| {
+            if it.parent.is_data_carrying(db) {
+                match it.eval(db) {
+                    Ok(x) => Some(format!("{}", x.enum_value().unwrap_or(x))),
+                    Err(_) => it.value(db).map(|x| format!("{:?}", x)),
+                }
+            } else {
+                None
+            }
         }),
         Definition::Const(it) => label_value_and_docs(db, it, |it| {
             let body = it.eval(db);

crates/ide/src/hover/tests.rs

@@ -698,6 +698,7 @@ fn hover_enum_variant() {
     check(
         r#"
 enum Option<T> {
+    Some(T)
     /// The None variant
     Non$0e
 }