Add ability to selectively enable errors (#19)

src/check_ast.rs

@@ -3,18 +3,33 @@ use std::collections::HashSet;
 use rustpython_parser::ast::{Arg, Arguments, Expr, ExprKind, Stmt, StmtKind, Suite};
 
 use crate::checks::{Check, CheckKind};
+use crate::settings::Settings;
 use crate::visitor;
 use crate::visitor::Visitor;
 
-#[derive(Default)]
+struct Checker<'a> {
-struct Checker {
+    settings: &'a Settings,
     checks: Vec<Check>,
 }
 
-impl Visitor for Checker {
+impl Checker<'_> {
+    pub fn new(settings: &Settings) -> Checker {
+        Checker {
+            settings,
+            checks: vec![],
+        }
+    }
+}
+
+impl Visitor for Checker<'_> {
     fn visit_stmt(&mut self, stmt: &Stmt) {
         match &stmt.node {
             StmtKind::ImportFrom { names, .. } => {
+                if self
+                    .settings
+                    .select
+                    .contains(CheckKind::ImportStarUsage.code())
+                {
                     for alias in names {
                         if alias.name == "*" {
                             self.checks.push(Check {
@@ -24,7 +39,9 @@ impl Visitor for Checker {
                         }
                     }
                 }
+            }
             StmtKind::If { test, .. } => {
+                if self.settings.select.contains(CheckKind::IfTuple.code()) {
                     if let ExprKind::Tuple { .. } = test.node {
                         self.checks.push(Check {
                             kind: CheckKind::IfTuple,
@@ -32,6 +49,7 @@ impl Visitor for Checker {
                         });
                     }
                 }
+            }
             _ => {}
         }
 
@@ -39,6 +57,11 @@ impl Visitor for Checker {
     }
 
     fn visit_expr(&mut self, expr: &Expr) {
+        if self
+            .settings
+            .select
+            .contains(CheckKind::FStringMissingPlaceholders.code())
+        {
             if let ExprKind::JoinedStr { values } = &expr.node {
                 if !values
                     .iter()
@@ -50,11 +73,17 @@ impl Visitor for Checker {
                     });
                 }
             }
+        }
 
         visitor::walk_expr(self, expr);
     }
 
     fn visit_arguments(&mut self, arguments: &Arguments) {
+        if self
+            .settings
+            .select
+            .contains(CheckKind::DuplicateArgumentName.code())
+        {
             // Collect all the arguments into a single vector.
             let mut all_arguments: Vec<&Arg> = arguments
                 .args
@@ -82,16 +111,17 @@ impl Visitor for Checker {
                 }
                 idents.insert(ident.clone());
             }
+        }
 
         visitor::walk_arguments(self, arguments);
     }
 }
 
-pub fn check_ast(python_ast: &Suite) -> Vec<Check> {
+pub fn check_ast(python_ast: &Suite, settings: &Settings) -> Vec<Check> {
     python_ast
         .iter()
         .flat_map(|stmt| {
-            let mut checker: Checker = Default::default();
+            let mut checker = Checker::new(settings);
             checker.visit_stmt(stmt);
             checker.checks
         })
@@ -101,15 +131,22 @@ pub fn check_ast(python_ast: &Suite) -> Vec<Check> {
 #[cfg(test)]
 mod tests {
     use rustpython_parser::ast::{Alias, Location, Stmt, StmtKind};
+    use std::collections::HashSet;
 
     use crate::check_ast::Checker;
-    use crate::checks::Check;
     use crate::checks::CheckKind::ImportStarUsage;
+    use crate::checks::{Check, CheckCode};
+    use crate::settings::Settings;
     use crate::visitor::Visitor;
 
     #[test]
     fn import_star_usage() {
-        let mut checker: Checker = Default::default();
+        let settings = Settings {
+            line_length: 88,
+            exclude: vec![],
+            select: HashSet::from([CheckCode::F403]),
+        };
+        let mut checker = Checker::new(&settings);
         checker.visit_stmt(&Stmt {
             location: Location::new(1, 1),
             custom: (),

src/check_lines.rs

@@ -1,7 +1,6 @@
 use rustpython_parser::ast::Location;
 
-use crate::checks::Check;
+use crate::checks::{Check, CheckKind};
-use crate::checks::CheckKind::LineTooLong;
 use crate::settings::Settings;
 
 pub fn check_lines(contents: &str, settings: &Settings) -> Vec<Check> {
@@ -9,19 +8,19 @@ pub fn check_lines(contents: &str, settings: &Settings) -> Vec<Check> {
         .lines()
         .enumerate()
         .filter_map(|(row, line)| {
-            if line.len() > settings.line_length {
+            if settings.select.contains(CheckKind::LineTooLong.code())
+                && line.len() > settings.line_length
+            {
                 let chunks: Vec<&str> = line.split_whitespace().collect();
-                if chunks.len() == 1 || (chunks.len() == 2 && chunks[0] == "#") {
+                if !(chunks.len() == 1 || (chunks.len() == 2 && chunks[0] == "#")) {
-                    None
+                    return Some(Check {
-                } else {
+                        kind: CheckKind::LineTooLong,
-                    Some(Check {
-                        kind: LineTooLong,
                         location: Location::new(row + 1, settings.line_length + 1),
-                    })
+                    });
                 }
-            } else {
+            }
+
             None
-            }
         })
         .collect()
 }

src/checks.rs

@@ -1,6 +1,33 @@
 use rustpython_parser::ast::Location;
 use serde::{Deserialize, Serialize};
 
+#[derive(Debug, PartialEq, Eq, Serialize, Deserialize, Hash)]
+pub enum CheckCode {
+    F831,
+    F541,
+    F634,
+    F403,
+    E501,
+}
+
+impl CheckCode {
+    pub fn as_str(&self) -> &str {
+        match self {
+            CheckCode::F831 => "F831",
+            CheckCode::F541 => "F541",
+            CheckCode::F634 => "F634",
+            CheckCode::F403 => "F403",
+            CheckCode::E501 => "E501",
+        }
+    }
+}
+
+#[allow(clippy::upper_case_acronyms)]
+pub enum LintSource {
+    AST,
+    Lines,
+}
+
 #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum CheckKind {
     DuplicateArgumentName,
@@ -11,14 +38,25 @@ pub enum CheckKind {
 }
 
 impl CheckKind {
+    /// Get the CheckKind for a corresponding code.
+    pub fn new(code: &CheckCode) -> Self {
+        match code {
+            CheckCode::F831 => CheckKind::DuplicateArgumentName,
+            CheckCode::F541 => CheckKind::FStringMissingPlaceholders,
+            CheckCode::F634 => CheckKind::IfTuple,
+            CheckCode::F403 => CheckKind::ImportStarUsage,
+            CheckCode::E501 => CheckKind::LineTooLong,
+        }
+    }
+
     /// A four-letter shorthand code for the check.
-    pub fn code(&self) -> &'static str {
+    pub fn code(&self) -> &'static CheckCode {
         match self {
-            CheckKind::DuplicateArgumentName => "F831",
+            CheckKind::DuplicateArgumentName => &CheckCode::F831,
-            CheckKind::FStringMissingPlaceholders => "F541",
+            CheckKind::FStringMissingPlaceholders => &CheckCode::F541,
-            CheckKind::IfTuple => "F634",
+            CheckKind::IfTuple => &CheckCode::F634,
-            CheckKind::ImportStarUsage => "F403",
+            CheckKind::ImportStarUsage => &CheckCode::F403,
-            CheckKind::LineTooLong => "E501",
+            CheckKind::LineTooLong => &CheckCode::E501,
         }
     }
 
@@ -32,6 +70,17 @@ impl CheckKind {
             CheckKind::LineTooLong => "Line too long",
         }
     }
+
+    /// The source for the checks (either the AST, or the physical lines).
+    pub fn lint_source(&self) -> &'static LintSource {
+        match self {
+            CheckKind::DuplicateArgumentName => &LintSource::AST,
+            CheckKind::FStringMissingPlaceholders => &LintSource::AST,
+            CheckKind::IfTuple => &LintSource::AST,
+            CheckKind::ImportStarUsage => &LintSource::AST,
+            CheckKind::LineTooLong => &LintSource::Lines,
+        }
+    }
 }
 
 #[derive(Debug, PartialEq, Eq)]

src/linter.rs

@@ -6,6 +6,7 @@ use rustpython_parser::parser;
 
 use crate::check_ast::check_ast;
 use crate::check_lines::check_lines;
+use crate::checks::{Check, CheckKind, LintSource};
 use crate::message::Message;
 use crate::settings::Settings;
 use crate::{cache, fs};
@@ -20,11 +21,31 @@ pub fn check_path(path: &Path, settings: &Settings, mode: &cache::Mode) -> Resul
     // Read the file from disk.
     let contents = fs::read_file(path)?;
 
-    // Run the linter.
+    // Aggregate all checks.
+    let mut checks: Vec<Check> = vec![];
+
+    // Run the AST-based checks.
+    if settings
+        .select
+        .iter()
+        .any(|check_code| matches!(CheckKind::new(check_code).lint_source(), LintSource::AST))
+    {
         let python_ast = parser::parse_program(&contents)?;
-    let messages: Vec<Message> = check_ast(&python_ast)
+        checks.extend(check_ast(&python_ast, settings));
+    }
+
+    // Run the lines-based checks.
+    if settings
+        .select
+        .iter()
+        .any(|check_code| matches!(CheckKind::new(check_code).lint_source(), LintSource::Lines))
+    {
+        checks.extend(check_lines(&contents, settings));
+    }
+
+    // Convert to messages.
+    let messages: Vec<Message> = checks
         .into_iter()
-        .chain(check_lines(&contents, settings))
         .map(|check| Message {
             kind: check.kind,
             location: check.location,
@@ -39,11 +60,13 @@ pub fn check_path(path: &Path, settings: &Settings, mode: &cache::Mode) -> Resul
 
 #[cfg(test)]
 mod tests {
+    use std::collections::HashSet;
     use std::path::Path;
 
     use anyhow::Result;
     use rustpython_parser::ast::Location;
 
+    use crate::checks::CheckCode;
     use crate::checks::CheckKind::{
         DuplicateArgumentName, FStringMissingPlaceholders, IfTuple, ImportStarUsage, LineTooLong,
     };
@@ -58,6 +81,7 @@ mod tests {
             &settings::Settings {
                 line_length: 88,
                 exclude: vec![],
+                select: HashSet::from([CheckCode::F831]),
             },
             &cache::Mode::None,
         )?;
@@ -93,6 +117,7 @@ mod tests {
             &settings::Settings {
                 line_length: 88,
                 exclude: vec![],
+                select: HashSet::from([CheckCode::F541]),
             },
             &cache::Mode::None,
         )?;
@@ -128,6 +153,7 @@ mod tests {
             &settings::Settings {
                 line_length: 88,
                 exclude: vec![],
+                select: HashSet::from([CheckCode::F634]),
             },
             &cache::Mode::None,
         )?;
@@ -158,6 +184,7 @@ mod tests {
             &settings::Settings {
                 line_length: 88,
                 exclude: vec![],
+                select: HashSet::from([CheckCode::F403]),
             },
             &cache::Mode::None,
         )?;
@@ -188,6 +215,7 @@ mod tests {
             &settings::Settings {
                 line_length: 88,
                 exclude: vec![],
+                select: HashSet::from([CheckCode::E501]),
             },
             &cache::Mode::None,
         )?;

src/message.rs

@@ -48,7 +48,7 @@ impl Message {
                                 .map(|code| code.trim())
                                 .filter(|code| !code.is_empty())
                             {
-                                if code == self.kind.code() {
+                                if code == self.kind.code().as_str() {
                                     return true;
                                 }
                             }
@@ -75,7 +75,7 @@ impl fmt::Display for Message {
             ":".cyan(),
             self.location.column(),
             ":".cyan(),
-            self.kind.code().red().bold(),
+            self.kind.code().as_str().red().bold(),
             self.kind.body()
         )
     }

src/pyproject.rs

@@ -1,5 +1,7 @@
+use std::collections::HashSet;
 use std::path::{Path, PathBuf};
 
+use crate::checks::CheckCode;
 use anyhow::Result;
 use common_path::common_path_all;
 use log::debug;
@@ -30,6 +32,7 @@ pub fn load_config<'a>(paths: impl IntoIterator<Item = &'a Path>) -> Result<(Pat
 pub struct Config {
     pub line_length: Option<usize>,
     pub exclude: Option<Vec<PathBuf>>,
+    pub select: Option<HashSet<CheckCode>>,
 }
 
 #[derive(Debug, PartialEq, Eq, Deserialize)]
@@ -82,8 +85,10 @@ fn find_project_root<'a>(sources: impl IntoIterator<Item = &'a Path>) -> Option<
 
 #[cfg(test)]
 mod tests {
+    use std::collections::HashSet;
     use std::path::Path;
 
+    use crate::checks::CheckCode;
     use anyhow::Result;
 
     use crate::pyproject::{
@@ -113,7 +118,8 @@ mod tests {
             Some(Tools {
                 linter: Some(Config {
                     line_length: None,
-                    exclude: None
+                    exclude: None,
+                    select: None,
                 })
             })
         );
@@ -130,7 +136,8 @@ line-length = 79
             Some(Tools {
                 linter: Some(Config {
                     line_length: Some(79),
-                    exclude: None
+                    exclude: None,
+                    select: None,
                 })
             })
         );
@@ -147,7 +154,26 @@ exclude = ["foo.py"]
             Some(Tools {
                 linter: Some(Config {
                     line_length: None,
-                    exclude: Some(vec![Path::new("foo.py").to_path_buf()])
+                    exclude: Some(vec![Path::new("foo.py").to_path_buf()]),
+                    select: None,
+                })
+            })
+        );
+
+        let pyproject: PyProject = toml::from_str(
+            r#"
+[tool.black]
+[tool.linter]
+select = ["E501"]
+"#,
+        )?;
+        assert_eq!(
+            pyproject.tool,
+            Some(Tools {
+                linter: Some(Config {
+                    line_length: None,
+                    exclude: None,
+                    select: Some(HashSet::from([CheckCode::E501])),
                 })
             })
         );
@@ -165,6 +191,15 @@ line_length = 79
             r#"
 [tool.black]
 [tool.linter]
+select = ["E123"]
+"#,
+        )
+        .is_err());
+
+        assert!(toml::from_str::<PyProject>(
+            r#"
+[tool.black]
+[tool.linter]
 line-length = 79
 other-attribute = 1
 "#,
@@ -193,7 +228,8 @@ other-attribute = 1
             config,
             Config {
                 line_length: Some(88),
-                exclude: Some(vec![Path::new("excluded.py").to_path_buf()])
+                exclude: Some(vec![Path::new("excluded.py").to_path_buf()]),
+                select: None,
             }
         );
 

src/settings.rs

@@ -1,5 +1,7 @@
+use std::collections::HashSet;
 use std::path::{Path, PathBuf};
 
+use crate::checks::CheckCode;
 use anyhow::Result;
 
 use crate::pyproject::load_config;
@@ -7,16 +9,14 @@ use crate::pyproject::load_config;
 pub struct Settings {
     pub line_length: usize,
     pub exclude: Vec<PathBuf>,
+    pub select: HashSet<CheckCode>,
 }
 
-static DEFAULT_MAX_LINE_LENGTH: usize = 88;
-
 impl Settings {
     pub fn from_paths<'a>(paths: impl IntoIterator<Item = &'a Path>) -> Result<Self> {
         let (project_root, config) = load_config(paths)?;
-
         Ok(Settings {
-            line_length: config.line_length.unwrap_or(DEFAULT_MAX_LINE_LENGTH),
+            line_length: config.line_length.unwrap_or(88),
             exclude: config
                 .exclude
                 .unwrap_or_default()
@@ -29,6 +29,15 @@ impl Settings {
                     }
                 })
                 .collect(),
+            select: config.select.unwrap_or_else(|| {
+                HashSet::from([
+                    CheckCode::F831,
+                    CheckCode::F541,
+                    CheckCode::F634,
+                    CheckCode::F403,
+                    CheckCode::E501,
+                ])
+            }),
         })
     }
 }