Add compare_nan fixer

selene-lib/src/lints/compare_nan.rs

@@ -30,17 +30,19 @@ impl Lint for CompareNanLint {
             .comparisons
             .iter()
             .map(|comparisons| {
+                let fixed_code = format!(
+                    "{variable} {operator} {variable}",
+                    variable = comparisons.variable,
+                    operator = comparisons.operator,
+                );
+
                 Diagnostic::new_complete(
                     "compare_nan",
                     "comparing things to nan directly is not allowed".to_owned(),
                     Label::new(comparisons.range),
-                    vec![format!(
-                        "try: `{variable} {operator} {variable}` instead",
-                        variable = comparisons.variable,
-                        operator = comparisons.operator,
-                    )],
+                    vec![format!("try: `{}` instead", fixed_code.clone())],
                     Vec::new(),
-                    None,
+                    Some(fixed_code),
                 )
             })
             .collect()

selene-lib/tests/lints/compare_nan/compare_nan_if.fixed.diff

@@ -0,0 +1,34 @@
+-if x == 0/0 then
++if x ~= x then
+ end
+
+-if x ~= 0/0 then
++if x == x then
+ end
+
+ if x ~= x then
+ end
+
+ if x >= 0/0 then
+ end
+
+ if 1 == 0/0 then
+ end
+
+ if 1 ~= 0/0 then
+ end
+
+ if 1 + 0/0 then
+ end
+
+ if y.foo() == 0/0 then
+ end
+
+ if y.bar() ~= 0/0 then
+ end
+
+ if x == 1 then
+ end
+
+ if 1 == 0 then
+ end

selene-lib/tests/lints/compare_nan/compare_nan_variables.fixed.diff

@@ -0,0 +1,15 @@
+ local _ = 0/0
+ local _ = 1 ~= 0/0
+ local _ = 2 == 0/0
+ local _ = 3 + 0/0
+ local _ = 4 >= 0/0
+-local _ = x ~= 0/0
+-local _ = x == 0/0
++local _ = x == x
++local _ = x ~= x
+ local _ = x >= 0/0
+ local _ = y.foo() == 0/0
+ local _ = y.bar() ~= 0/0
+
+ local _ = x == 1
+ local _ = 1 == 0