Merge #440

440: Implement type inference for boolean operators r=flodiebold a=marcusklaas

Tried implementing the easiest part of https://github.com/rust-analyzer/rust-analyzer/issues/390. Hope this is somewhat close to what the intent of the issue was. Found it surprisingly easy to find my way around the repository - it's well organized!

Very grateful for any pointers.

Co-authored-by: Marcus Klaas de Vries <mail@marcusklaas.nl>

crates/ra_hir/src/ty/tests.rs

@@ -156,6 +156,30 @@ impl S {
     );
 }
 
+#[test]
+fn infer_boolean_op() {
+    check_inference(
+        r#"
+fn f(x: bool) -> i32 {
+    0i32
+}
+
+fn test() {
+    let x = a && b;
+    let y = true || false;
+    let z = x == y;
+    let h = CONST_1 <= CONST_2;
+    let c = f(z || y) + 5;
+    let d = b;
+    let e = 3i32 && "hello world";
+
+    10 < 3
+}
+"#,
+        "0008_boolean_op.txt",
+    );
+}
+
 fn infer(content: &str) -> String {
     let (db, _, file_id) = MockDatabase::with_single_file(content);
     let source_file = db.source_file(file_id);