Warn the user if an explicitly selected check code is ignored (#356)

src/cli.rs

@@ -0,0 +1,136 @@
+use std::fmt;
+use std::path::PathBuf;
+
+use clap::{command, Parser};
+use log::warn;
+use regex::Regex;
+
+use crate::checks::CheckCode;
+use crate::printer::SerializationFormat;
+use crate::pyproject::StrCheckCodePair;
+use crate::settings::PythonVersion;
+use crate::RawSettings;
+
+#[derive(Debug, Parser)]
+#[command(author, about = "ruff: An extremely fast Python linter.")]
+#[command(version)]
+pub struct Cli {
+    #[arg(required = true)]
+    pub files: Vec<PathBuf>,
+    /// Enable verbose logging.
+    #[arg(short, long)]
+    pub verbose: bool,
+    /// Disable all logging (but still exit with status code "1" upon detecting errors).
+    #[arg(short, long)]
+    pub quiet: bool,
+    /// Exit with status code "0", even upon detecting errors.
+    #[arg(short, long)]
+    pub exit_zero: bool,
+    /// Run in watch mode by re-running whenever files change.
+    #[arg(short, long)]
+    pub watch: bool,
+    /// Attempt to automatically fix lint errors.
+    #[arg(short, long)]
+    pub fix: bool,
+    /// Disable cache reads.
+    #[arg(short, long)]
+    pub no_cache: bool,
+    /// List of error codes to enable.
+    #[arg(long, value_delimiter = ',')]
+    pub select: Vec<CheckCode>,
+    /// Like --select, but adds additional error codes on top of the selected ones.
+    #[arg(long, value_delimiter = ',')]
+    pub extend_select: Vec<CheckCode>,
+    /// List of error codes to ignore.
+    #[arg(long, value_delimiter = ',')]
+    pub ignore: Vec<CheckCode>,
+    /// Like --ignore, but adds additional error codes on top of the ignored ones.
+    #[arg(long, value_delimiter = ',')]
+    pub extend_ignore: Vec<CheckCode>,
+    /// List of paths, used to exclude files and/or directories from checks.
+    #[arg(long, value_delimiter = ',')]
+    pub exclude: Vec<String>,
+    /// Like --exclude, but adds additional files and directories on top of the excluded ones.
+    #[arg(long, value_delimiter = ',')]
+    pub extend_exclude: Vec<String>,
+    /// List of mappings from file pattern to code to exclude
+    #[arg(long, value_delimiter = ',')]
+    pub per_file_ignores: Vec<StrCheckCodePair>,
+    /// Output serialization format for error messages.
+    #[arg(long, value_enum, default_value_t=SerializationFormat::Text)]
+    pub format: SerializationFormat,
+    /// See the files ruff will be run against with the current settings.
+    #[arg(long)]
+    pub show_files: bool,
+    /// See ruff's settings.
+    #[arg(long)]
+    pub show_settings: bool,
+    /// Enable automatic additions of noqa directives to failing lines.
+    #[arg(long)]
+    pub add_noqa: bool,
+    /// Regular expression matching the name of dummy variables.
+    #[arg(long)]
+    pub dummy_variable_rgx: Option<Regex>,
+    /// The minimum Python version that should be supported.
+    #[arg(long)]
+    pub target_version: Option<PythonVersion>,
+    /// Round-trip auto-formatting.
+    // TODO(charlie): This should be a sub-command.
+    #[arg(long, hide = true)]
+    pub autoformat: bool,
+}
+
+pub enum Warnable {
+    Select,
+    ExtendSelect,
+}
+
+impl fmt::Display for Warnable {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Warnable::Select => fmt.write_str("--select"),
+            Warnable::ExtendSelect => fmt.write_str("--extend-select"),
+        }
+    }
+}
+
+/// Warn the user if they attempt to enable a code that won't be respected.
+pub fn warn_on(
+    flag: Warnable,
+    codes: &Vec<CheckCode>,
+    cli_ignore: &Vec<CheckCode>,
+    cli_extend_ignore: &Vec<CheckCode>,
+    pyproject_settings: &RawSettings,
+    pyproject_path: &Option<PathBuf>,
+) {
+    for code in codes {
+        if !cli_ignore.is_empty() {
+            if cli_ignore.contains(code) {
+                warn!("{code:?} was passed to {flag}, but ignored via --ignore")
+            }
+        } else if pyproject_settings.ignore.contains(code) {
+            if let Some(path) = pyproject_path {
+                warn!(
+                    "{code:?} was passed to {flag}, but ignored by the `ignore` field in {}",
+                    path.to_string_lossy()
+                )
+            } else {
+                warn!("{code:?} was passed to {flag}, but ignored by the default `ignore` field",)
+            }
+        }
+        if !cli_extend_ignore.is_empty() {
+            if cli_extend_ignore.contains(code) {
+                warn!("{code:?} was passed to {flag}, but ignored via --extend-ignore")
+            }
+        } else if pyproject_settings.extend_ignore.contains(code) {
+            if let Some(path) = pyproject_path {
+                warn!(
+                    "{code:?} was passed to {flag}, but ignored by the `extend_ignore` field in {}",
+                    path.to_string_lossy()
+                )
+            } else {
+                warn!("{code:?} was passed to {flag}, but ignored by the default `extend_ignore` field")
+            }
+        }
+    }
+}