12 files changed, 68 insertions, 43 deletions

diff --git a/lib/src/lib.rs b/lib/src/lib.rs
index 196cbf8..e6bfa6c 100644
--- a/lib/src/lib.rs
+++ b/lib/src/lib.rs
@@ -226,25 +226,29 @@ pub trait Rule {
 /// Contains information about the lint itself. Do not implement manually,
 /// look at the `lint` attribute macro instead for implementing rules
 pub trait Metadata {
-    fn name() -> &'static str
-    where
-        Self: Sized;
-    fn note() -> &'static str
-    where
-        Self: Sized;
-    fn code() -> u32
-    where
-        Self: Sized;
-    fn report() -> Report
-    where
-        Self: Sized;
+    fn name(&self) -> &'static str;
+    fn note(&self) -> &'static str;
+    fn code(&self) -> u32;
+    fn report(&self) -> Report;
     fn match_with(&self, with: &SyntaxKind) -> bool;
     fn match_kind(&self) -> Vec<SyntaxKind>;
 }
 
+/// Contains offline explaination for each lint
+/// The `lint` macro scans nearby doc comments for
+/// explainations and derives this trait.
+///
+/// FIXME: the lint macro does way too much, maybe
+/// split it into smaller macros.
+pub trait Explain {
+    fn explaination(&self) -> &'static str {
+        "no explaination found"
+    }
+}
+
 /// Combines Rule and Metadata, do not implement manually, this is derived by
 /// the `lint` macro.
-pub trait Lint: Metadata + Rule + Send + Sync {}
+pub trait Lint: Metadata + Explain + Rule + Send + Sync {}
 
 /// Helper utility to take lints from modules and insert them into a map for efficient
 /// access. Mapping is from a SyntaxKind to a list of lints that apply on that Kind.
diff --git a/lib/src/lints/bool_comparison.rs b/lib/src/lints/bool_comparison.rs
index 0b5733b..6636faf 100644
--- a/lib/src/lints/bool_comparison.rs
+++ b/lib/src/lints/bool_comparison.rs
@@ -1,4 +1,4 @@
-use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+use crate::{make, Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
@@ -7,6 +7,28 @@ use rnix::{
     NodeOrToken, SyntaxElement, SyntaxKind, SyntaxNode,
 };
 
+/// What it does
+/// ------------
+/// Checks for expressions of the form x == true, x != true and
+/// suggests using the variable directly.
+///
+/// Why is this bad?
+/// ----------------
+/// Unnecessary code.
+///
+/// Example
+/// --------
+/// Instead of checking the value of x:
+///
+///     if x == true
+///     then 0
+///     else 1
+///
+/// Use x directly:
+///
+///     if x
+///     then 0
+///     else 1
 #[lint(
     name = "bool_comparison",
     note = "Unnecessary comparison with boolean",
@@ -71,7 +93,7 @@ impl Rule for BoolComparison {
                     non_bool_side,
                     bool_side
                 );
-                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+                Some(self.report().suggest(at, message, Suggestion::new(at, replacement)))
             } else {
                 None
             }
diff --git a/lib/src/lints/collapsible_let_in.rs b/lib/src/lints/collapsible_let_in.rs
index 878d218..cb76c37 100644
--- a/lib/src/lints/collapsible_let_in.rs
+++ b/lib/src/lints/collapsible_let_in.rs
@@ -1,12 +1,12 @@
-use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+use crate::{make, Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
-use rowan::Direction;
 use rnix::{
     types::{LetIn, TypedNode},
-    NodeOrToken, SyntaxElement, SyntaxKind, TextRange
+    NodeOrToken, SyntaxElement, SyntaxKind, TextRange,
 };
+use rowan::Direction;
 
 #[lint(
     name = "collapsible let in",
@@ -47,7 +47,7 @@ impl Rule for CollapsibleLetIn {
                 let replacement = make::empty().node().clone();
 
                 Some(
-                    Self::report()
+                    self.report()
                         .diagnostic(first_annotation, first_message)
                         .suggest(second_annotation, second_message, Suggestion::new(replacement_at, replacement))
                 )
@@ -57,4 +57,3 @@ impl Rule for CollapsibleLetIn {
         }
     }
 }
-
diff --git a/lib/src/lints/empty_let_in.rs b/lib/src/lints/empty_let_in.rs
index aae1377..4e0887d 100644
--- a/lib/src/lints/empty_let_in.rs
+++ b/lib/src/lints/empty_let_in.rs
@@ -1,12 +1,13 @@
-use crate::{Lint, Metadata, Report, Rule, Suggestion};
+use crate::{Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
 use rnix::{
-    types::{LetIn, TypedNode, EntryHolder},
+    types::{EntryHolder, LetIn, TypedNode},
     NodeOrToken, SyntaxElement, SyntaxKind,
 };
 
+/// empty let-in found
 #[lint(
     name = "empty let-in",
     note = "Useless let-in expression",
@@ -31,11 +32,10 @@ impl Rule for EmptyLetIn {
                 let at = node.text_range();
                 let replacement = body;
                 let message = "This let-in expression has no entries";
-                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+                Some(self.report().suggest(at, message, Suggestion::new(at, replacement)))
             } else {
                 None
             }
         }
     }
 }
-
diff --git a/lib/src/lints/empty_pattern.rs b/lib/src/lints/empty_pattern.rs
index 6fb7558..ef47c69 100644
--- a/lib/src/lints/empty_pattern.rs
+++ b/lib/src/lints/empty_pattern.rs
@@ -1,4 +1,4 @@
-use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+use crate::{make, Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
@@ -28,7 +28,7 @@ impl Rule for EmptyPattern {
                 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)))
+                Some(self.report().suggest(at, message, Suggestion::new(at, replacement)))
             } else {
                 None
             }
diff --git a/lib/src/lints/eta_reduction.rs b/lib/src/lints/eta_reduction.rs
index 79a5101..b329ae8 100644
--- a/lib/src/lints/eta_reduction.rs
+++ b/lib/src/lints/eta_reduction.rs
@@ -1,4 +1,4 @@
-use crate::{Lint, Metadata, Report, Rule, Suggestion};
+use crate::{Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
@@ -43,7 +43,7 @@ impl Rule for EtaReduction {
                         "Found eta-reduction: `{}`",
                         replacement.text().to_string()
                     );
-                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+                Some(self.report().suggest(at, message, Suggestion::new(at, replacement)))
             } else {
                 None
             }
diff --git a/lib/src/lints/legacy_let_syntax.rs b/lib/src/lints/legacy_let_syntax.rs
index 2087e27..8b37df8 100644
--- a/lib/src/lints/legacy_let_syntax.rs
+++ b/lib/src/lints/legacy_let_syntax.rs
@@ -1,4 +1,4 @@
-use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+use crate::{make, Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
@@ -36,7 +36,7 @@ impl Rule for ManualInherit {
                 let message = "Prefer `rec` over undocumented `let` syntax";
                 let replacement = selected.node().clone();
 
-                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+                Some(self.report().suggest(at, message, Suggestion::new(at, replacement)))
             } else {
                 None
             }
diff --git a/lib/src/lints/manual_inherit.rs b/lib/src/lints/manual_inherit.rs
index 0a6933c..1c10cbf 100644
--- a/lib/src/lints/manual_inherit.rs
+++ b/lib/src/lints/manual_inherit.rs
@@ -1,4 +1,4 @@
-use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+use crate::{make, Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
@@ -35,7 +35,7 @@ impl Rule for ManualInherit {
                 let at = node.text_range();
                 let replacement = make::inherit_stmt(&[key]).node().clone();
                 let message = "This assignment is better written with `inherit`";
-                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+                Some(self.report().suggest(at, message, Suggestion::new(at, replacement)))
             } else {
                 None
             }
diff --git a/lib/src/lints/manual_inherit_from.rs b/lib/src/lints/manual_inherit_from.rs
index 794aaf9..146d55b 100644
--- a/lib/src/lints/manual_inherit_from.rs
+++ b/lib/src/lints/manual_inherit_from.rs
@@ -1,4 +1,4 @@
-use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+use crate::{make, Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
@@ -40,7 +40,7 @@ impl Rule for ManualInherit {
                     make::inherit_from_stmt(set, &[key]).node().clone()
                 };
                 let message = "This assignment is better written with `inherit`";
-                Some(Self::report().suggest(at, message, Suggestion::new(at, replacement)))
+                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
index aebc549..ad1aba8 100644
--- a/lib/src/lints/redundant_pattern_bind.rs
+++ b/lib/src/lints/redundant_pattern_bind.rs
@@ -1,4 +1,4 @@
-use crate::{Lint, Metadata, Report, Rule, Suggestion};
+use crate::{Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
@@ -32,7 +32,7 @@ impl Rule for RedundantPatternBind {
                 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)))
+                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
index 4d1ed69..2831c1b 100644
--- a/lib/src/lints/unquoted_splice.rs
+++ b/lib/src/lints/unquoted_splice.rs
@@ -1,4 +1,4 @@
-use crate::{make, Lint, Metadata, Report, Rule, Suggestion};
+use crate::{make, Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
@@ -24,7 +24,7 @@ impl Rule for UnquotedSplice {
                 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)))
+                Some(self.report().suggest(at, message, Suggestion::new(at, replacement)))
             } else {
                 None
             }
diff --git a/lib/src/lints/useless_parens.rs b/lib/src/lints/useless_parens.rs
index 2d6ba8f..9dfeabb 100644
--- a/lib/src/lints/useless_parens.rs
+++ b/lib/src/lints/useless_parens.rs
@@ -1,9 +1,9 @@
-use crate::{Lint, Metadata, Report, Rule, Suggestion, Diagnostic};
+use crate::{Diagnostic, Metadata, Report, Rule, Suggestion};
 
 use if_chain::if_chain;
 use macros::lint;
 use rnix::{
-    types::{ParsedType, KeyValue, Paren, TypedNode, Wrapper},
+    types::{KeyValue, Paren, ParsedType, TypedNode, Wrapper},
     NodeOrToken, SyntaxElement, SyntaxKind,
 };
 
@@ -27,7 +27,7 @@ impl Rule for UselessParens {
 
             if let Some(diagnostic) = do_thing(parsed_type_node);
             then {
-                let mut report = Self::report();
+                let mut report = self.report();
                 report.diagnostics.push(diagnostic);
                 Some(report)
             } else {
@@ -79,7 +79,7 @@ fn do_thing(parsed_type_node: ParsedType) -> Option<Diagnostic> {
             if let Some(parsed_inner) = ParsedType::cast(inner_node);
             if matches!(
                 parsed_inner,
-                ParsedType::List(_) 
+                ParsedType::List(_)
                 | ParsedType::Paren(_)
                 | ParsedType::Str(_)
                 | ParsedType::AttrSet(_)
@@ -95,6 +95,6 @@ fn do_thing(parsed_type_node: ParsedType) -> Option<Diagnostic> {
                 None
             }
         },
-        _ => None
+        _ => None,
     }
 }