9 files changed, 128 insertions, 3 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 3be258a..d4df006 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -388,7 +388,7 @@ checksum = "b203e79e90905594272c1c97c7af701533d42adaab0beb3859018e477d54a3b0"
 
 [[package]]
 name = "statix"
-version = "0.2.0"
+version = "0.2.3"
 dependencies = [
  "ariadne",
  "clap",
diff --git a/bin/Cargo.toml b/bin/Cargo.toml
index 971fb47..78f4b9c 100644
--- a/bin/Cargo.toml
+++ b/bin/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "statix"
-version = "0.2.2"
+version = "0.2.3"
 edition = "2018"
 license = "MIT"
 
diff --git a/flake.nix b/flake.nix
index 26190aa..55af012 100644
--- a/flake.nix
+++ b/flake.nix
@@ -49,7 +49,7 @@
 
           statix = with final; pkgs.stdenv.mkDerivation {
             pname = "statix";
-            version = "v0.2.2";
+            version = "v0.2.3";
             src = builtins.path {
               path = ./.;
               name = "statix";
diff --git a/lib/src/lints.rs b/lib/src/lints.rs
index f7e98ac..09cd77c 100644
--- a/lib/src/lints.rs
+++ b/lib/src/lints.rs
@@ -9,4 +9,7 @@ lint_map! {
     collapsible_let_in,
     eta_reduction,
     useless_parens,
+    unquoted_splice,
+    empty_pattern,
+    redundant_pattern_bind,
 }
diff --git a/lib/src/lints/empty_pattern.rs b/lib/src/lints/empty_pattern.rs
new file mode 100644
index 0000000..6fb7558
--- /dev/null
+++ b/lib/src/lints/empty_pattern.rs
@@ -0,0 +1,37 @@
+use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+
+use if_chain::if_chain;
+use macros::lint;
+use rnix::{
+    types::{Pattern, TypedNode},
+    NodeOrToken, SyntaxElement, SyntaxKind,
+};
+
+#[lint(
+    name = "empty pattern",
+    note = "Found empty pattern in function argument",
+    code = 10,
+    match_with = SyntaxKind::NODE_PATTERN
+)]
+struct EmptyPattern;
+
+impl Rule for EmptyPattern {
+    fn validate(&self, node: &SyntaxElement) -> Option<Report> {
+        if_chain! {
+            if let NodeOrToken::Node(node) = node;
+            if let Some(pattern) = Pattern::cast(node.clone());
+            // no patterns within `{ }`
+            if pattern.entries().count() == 0;
+            // pattern is not bound
+            if pattern.at().is_none();
+            then {
+                let at = node.text_range();
+                let message = "This pattern is empty, use `_` instead";
+                let replacement = make::ident("_").node().clone();
+                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+            } else {
+                None
+            }
+        }
+    }
+}
diff --git a/lib/src/lints/redundant_pattern_bind.rs b/lib/src/lints/redundant_pattern_bind.rs
new file mode 100644
index 0000000..aebc549
--- /dev/null
+++ b/lib/src/lints/redundant_pattern_bind.rs
@@ -0,0 +1,41 @@
+use crate::{Lint, Metadata, Report, Rule, Suggestion};
+
+use if_chain::if_chain;
+use macros::lint;
+use rnix::{
+    types::{Pattern, TokenWrapper, TypedNode},
+    NodeOrToken, SyntaxElement, SyntaxKind,
+};
+
+#[lint(
+    name = "redundant pattern bind",
+    note = "Found redundant pattern bind in function argument",
+    code = 10,
+    match_with = SyntaxKind::NODE_PATTERN
+)]
+struct RedundantPatternBind;
+
+impl Rule for RedundantPatternBind {
+    fn validate(&self, node: &SyntaxElement) -> Option<Report> {
+        if_chain! {
+            if let NodeOrToken::Node(node) = node;
+            if let Some(pattern) = Pattern::cast(node.clone());
+            // no patterns within `{ }`
+            if pattern.entries().count() == 0;
+
+            // pattern is just ellipsis
+            if pattern.ellipsis();
+
+            // pattern is bound
+            if let Some(ident) =  pattern.at();
+            then {
+                let at = node.text_range();
+                let message = format!("This pattern bind is redundant, use `{}` instead", ident.as_str());
+                let replacement = ident.node().clone();
+                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+            } else {
+                None
+            }
+        }
+    }
+}
diff --git a/lib/src/lints/unquoted_splice.rs b/lib/src/lints/unquoted_splice.rs
new file mode 100644
index 0000000..4d1ed69
--- /dev/null
+++ b/lib/src/lints/unquoted_splice.rs
@@ -0,0 +1,33 @@
+use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+
+use if_chain::if_chain;
+use macros::lint;
+use rnix::{
+    types::{Dynamic, TypedNode},
+    NodeOrToken, SyntaxElement, SyntaxKind,
+};
+
+#[lint(
+    name = "unquoted splice",
+    note = "Found unquoted splice expression",
+    code = 9,
+    match_with = SyntaxKind::NODE_DYNAMIC
+)]
+struct UnquotedSplice;
+
+impl Rule for UnquotedSplice {
+    fn validate(&self, node: &SyntaxElement) -> Option<Report> {
+        if_chain! {
+            if let NodeOrToken::Node(node) = node;
+            if Dynamic::cast(node.clone()).is_some();
+            then {
+                let at = node.text_range();
+                let replacement = make::quote(&node).node().clone();
+                let message = "Consider quoting this splice expression";
+                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+            } else {
+                None
+            }
+        }
+    }
+}
diff --git a/lib/src/make.rs b/lib/src/make.rs
index 217ba12..44adae6 100644
--- a/lib/src/make.rs
+++ b/lib/src/make.rs
@@ -24,6 +24,10 @@ pub fn parenthesize(node: &SyntaxNode) -> types::Paren {
     ast_from_text(&format!("({})", node))
 }
 
+pub fn quote(node: &SyntaxNode) -> types::Str {
+    ast_from_text(&format!("\"{}\"", node))
+}
+
 pub fn unary_not(node: &SyntaxNode) -> types::UnaryOp {
     ast_from_text(&format!("!{}", node))
 }
diff --git a/notes.txt b/notes.txt
index 071e502..0e70373 100644
--- a/notes.txt
+++ b/notes.txt
@@ -40,6 +40,13 @@ Lint ideas
 - manual map over list
 - merge inherit
 - merge inherit-from
+- empty inherit
+- useless antiquote/splice (where is antiquote truly
+  required?)
+- useless variadic (things like `{...} : expr`, replace with
+  `_: expr`)
+- redundant pattern `{...} @ inputs : expr`, replace with
+  `inputs: expr`
 
 Extensions
 ----------