sqf: add lint for unneeded not (#803)

libs/sqf/src/analyze/lints/s19_extra_not.rs

@@ -0,0 +1,134 @@
+use std::{ops::Range, sync::Arc};
+
+use hemtt_common::config::LintConfig;
+use hemtt_workspace::{
+    lint::{AnyLintRunner, Lint, LintRunner},
+    reporting::{Code, Codes, Diagnostic, Processed, Severity},
+};
+
+use crate::{analyze::SqfLintData, Expression, UnaryCommand};
+
+crate::analyze::lint!(LintS19ExtraNot);
+
+impl Lint<SqfLintData> for LintS19ExtraNot {
+    fn ident(&self) -> &'static str {
+        "extra_not"
+    }
+
+    fn sort(&self) -> u32 {
+        190
+    }
+
+    fn description(&self) -> &'static str {
+        "Checks for extra not before a comparison"
+    }
+
+    fn documentation(&self) -> &'static str {
+        r"### Example
+
+**Incorrect**
+```sqf
+! (5 isEqualTo 6)
+```
+**Correct**
+```sqf
+(5 isNotEqualTo 6)
+```
+"
+    }
+
+    fn default_config(&self) -> LintConfig {
+        LintConfig::help()
+    }
+
+    fn runners(&self) -> Vec<Box<dyn AnyLintRunner<SqfLintData>>> {
+        vec![Box::new(Runner)]
+    }
+}
+
+struct Runner;
+impl LintRunner<SqfLintData> for Runner {
+    type Target = crate::Expression;
+
+    fn run(
+        &self,
+        _project: Option<&hemtt_common::config::ProjectConfig>,
+        config: &LintConfig,
+        processed: Option<&hemtt_workspace::reporting::Processed>,
+        target: &Self::Target,
+        _data: &SqfLintData,
+    ) -> Codes {
+        const COMPARISON_CMDS: &[&str] = &[
+            "==",
+            "!=",
+            "isEqualTo",
+            "isNotEqualTo",
+            "<",
+            "<=",
+            ">",
+            ">=",
+        ];
+        let Some(processed) = processed else {
+            return Vec::new();
+        };
+        let Expression::UnaryCommand(UnaryCommand::Not, rhs, range) = target else {
+            return Vec::new();
+        };
+        let Expression::BinaryCommand(ref last_cmd, _, _, _) = **rhs else {
+            return Vec::new();
+        };
+        if !COMPARISON_CMDS.contains(&last_cmd.as_str()) {
+            return Vec::new();
+        }
+
+        vec![Arc::new(Code19ExtraNot::new(
+            range.clone(),
+            processed,
+            config.severity(),
+        ))]
+    }
+}
+
+#[allow(clippy::module_name_repetitions)]
+pub struct Code19ExtraNot {
+    span: Range<usize>,
+    severity: Severity,
+    diagnostic: Option<Diagnostic>,
+}
+
+impl Code for Code19ExtraNot {
+    fn ident(&self) -> &'static str {
+        "L-S19"
+    }
+    fn link(&self) -> Option<&str> {
+        Some("/analysis/sqf.html#extra_not")
+    }
+    fn severity(&self) -> Severity {
+        self.severity
+    }
+    fn message(&self) -> String {
+        "Unneeded Not".to_string()
+    }
+    fn label_message(&self) -> String {
+        "unneeded not".to_string()
+    }
+    fn diagnostic(&self) -> Option<Diagnostic> {
+        self.diagnostic.clone()
+    }
+}
+
+impl Code19ExtraNot {
+    #[must_use]
+    pub fn new(span: Range<usize>, processed: &Processed, severity: Severity) -> Self {
+        Self {
+            span,
+            severity,
+            diagnostic: None,
+        }
+        .generate_processed(processed)
+    }
+    fn generate_processed(mut self, processed: &Processed) -> Self {
+        self.diagnostic = Diagnostic::from_code_processed(&self, self.span.clone(), processed);
+        self
+    }
+}

libs/sqf/tests/lints.rs

@@ -32,6 +32,7 @@ lint!(s09_banned_command);
 lint!(s11_if_not_else);
 lint!(s17_var_all_caps);
 lint!(s18_in_vehicle_check);
+lint!(s19_extra_not);
 lint!(s20_bool_static_comparison);
 lint!(s21_invalid_comparisons);
 lint!(s22_this_call);

libs/sqf/tests/lints/s19_extra_not.sqf

@@ -0,0 +1 @@
+! (5 isEqualTo 6)

libs/sqf/tests/snapshots/lints__simple_s19_extra_not.snap

@@ -0,0 +1,9 @@
+---
+source: libs/sqf/tests/lints.rs
+expression: lint(stringify! (s19_extra_not))
+---
+help[L-S19]: Unneeded Not
+  ┌─ s19_extra_not.sqf:1:1
+  │
+1 │ ! (5 isEqualTo 6)
+  │ ^ unneeded not