new lint: useless_has_attr

3 files changed, 45 insertions, 1 deletions

diff --git a/bin/tests/data/useless_has_attr.nix b/bin/tests/data/useless_has_attr.nix
new file mode 100644
index 0000000..f4c9fd5
--- /dev/null
+++ b/bin/tests/data/useless_has_attr.nix
@@ -0,0 +1,9 @@
+[
+  # trivial
+  (if x ? a then x.a else default)
+  (if x.a ? b then x.a.b else default)
+  (if x ? a.b then x.a.b else default)
+
+  # complex body
+  (if x ? a then x.a else if b then c else d)
+]
diff --git a/bin/tests/main.rs b/bin/tests/main.rs
index 3403f65..3425cfa 100644
--- a/bin/tests/main.rs
+++ b/bin/tests/main.rs
@@ -64,5 +64,6 @@ test_lint! {
     faster_groupby => session_info!("2.5"),
     faster_zipattrswith => session_info!("2.6"),
     deprecated_to_path => session_info!("2.4"),
-    bool_simplification
+    bool_simplification,
+    useless_has_attr
 }
diff --git a/bin/tests/snapshots/main__useless_has_attr.snap b/bin/tests/snapshots/main__useless_has_attr.snap
new file mode 100644
index 0000000..df72eaf
--- /dev/null
+++ b/bin/tests/snapshots/main__useless_has_attr.snap
@@ -0,0 +1,34 @@
+---
+source: bin/tests/main.rs
+expression: "&out"
+
+---
+[W19] Warning: This `if` expression can be simplified with `or`
+   ╭─[data/useless_has_attr.nix:3:4]
+   │
+ 3 │   (if x ? a then x.a else default)
+   ·    ───────────────┬──────────────  
+   ·                   ╰──────────────── Consider using x.a or default instead of this if expression
+───╯
+[W19] Warning: This `if` expression can be simplified with `or`
+   ╭─[data/useless_has_attr.nix:4:4]
+   │
+ 4 │   (if x.a ? b then x.a.b else default)
+   ·    ─────────────────┬────────────────  
+   ·                     ╰────────────────── Consider using x.a.b or default instead of this if expression
+───╯
+[W19] Warning: This `if` expression can be simplified with `or`
+   ╭─[data/useless_has_attr.nix:5:4]
+   │
+ 5 │   (if x ? a.b then x.a.b else default)
+   ·    ─────────────────┬────────────────  
+   ·                     ╰────────────────── Consider using x.a.b or default instead of this if expression
+───╯
+[W19] Warning: This `if` expression can be simplified with `or`
+   ╭─[data/useless_has_attr.nix:8:4]
+   │
+ 8 │   (if x ? a then x.a else if b then c else d)
+   ·    ────────────────────┬────────────────────  
+   ·                        ╰────────────────────── Consider using x.a or (if b then c else d) instead of this if expression
+───╯
+