Add Applicability to Fix (#4303)

Co-authored-by: Micha Reiser <micha@reiser.io>

crates/ruff_diagnostics/src/diagnostic.rs

@@ -47,6 +47,7 @@ impl Diagnostic {
     /// Set the [`Fix`] used to fix the diagnostic.
     #[inline]
     #[deprecated(note = "Use `Diagnostic::set_fix` instead.")]
+    #[allow(deprecated)]
     pub fn set_fix_from_edit(&mut self, edit: Edit) {
         self.fix = Some(Fix::unspecified(edit));
     }
@@ -62,6 +63,7 @@ impl Diagnostic {
     /// Set the [`Fix`] used to fix the diagnostic, if the provided function returns `Ok`.
     /// Otherwise, log the error.
     #[inline]
+    #[allow(deprecated)]
     pub fn try_set_fix(&mut self, func: impl FnOnce() -> Result<Fix>) {
         match func() {
             Ok(fix) => self.fix = Some(fix),
@@ -73,6 +75,7 @@ impl Diagnostic {
     /// Otherwise, log the error.
     #[inline]
     #[deprecated(note = "Use Diagnostic::try_set_fix instead")]
+    #[allow(deprecated)]
     pub fn try_set_fix_from_edit(&mut self, func: impl FnOnce() -> Result<Edit>) {
         match func() {
             Ok(edit) => self.fix = Some(Fix::unspecified(edit)),

crates/ruff_diagnostics/src/fix.rs

@@ -4,23 +4,105 @@ use serde::{Deserialize, Serialize};
 
 use crate::edit::Edit;
 
+/// Indicates confidence in the correctness of a suggested fix.
+#[derive(Default, Copy, Clone, Debug, Hash, PartialEq, Eq, PartialOrd, Ord)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub enum Applicability {
+    /// The fix is definitely what the user intended, or maintains the exact meaning of the code.
+    /// This fix should be automatically applied.
+    Automatic,
+
+    /// The fix may be what the user intended, but it is uncertain.
+    /// The fix should result in valid code if it is applied.
+    /// The fix can be applied with user opt-in.
+    Suggested,
+
+    /// The fix has a good chance of being incorrect or the code be incomplete.
+    /// The fix may result in invalid code if it is applied.
+    /// The fix should only be manually applied by the user.
+    Manual,
+
+    /// The applicability of the fix is unknown.
+    #[default]
+    Unspecified,
+}
+
 /// A collection of [`Edit`] elements to be applied to a source file.
 #[derive(Debug, PartialEq, Eq, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct Fix {
     edits: Vec<Edit>,
+    applicability: Applicability,
 }
 
 impl Fix {
     /// Create a new [`Fix`] with an unspecified applicability from an [`Edit`] element.
+    #[deprecated(
+        note = "Use `Fix::automatic`, `Fix::suggested`, or `Fix::manual` instead to specify an applicability."
+    )]
     pub fn unspecified(edit: Edit) -> Self {
-        Self { edits: vec![edit] }
+        Self {
+            edits: vec![edit],
+            applicability: Applicability::Unspecified,
+        }
     }
 
-    /// Create a new [`Fix`] with unspecified applicability from multiple [`Edit`] elements.
+    /// Create a new [`Fix`] with an unspecified applicability from multiple [`Edit`] elements.
+    #[deprecated(
+        note = "Use `Fix::automatic_edits`, `Fix::suggested_edits`, or `Fix::manual_edits` instead to specify an applicability."
+    )]
     pub fn unspecified_edits(edit: Edit, rest: impl IntoIterator<Item = Edit>) -> Self {
         Self {
             edits: std::iter::once(edit).chain(rest.into_iter()).collect(),
+            applicability: Applicability::Unspecified,
+        }
+    }
+
+    /// Create a new [`Fix`] with [automatic applicability](Applicability::Automatic) from an [`Edit`] element.
+    pub fn automatic(edit: Edit) -> Self {
+        Self {
+            edits: vec![edit],
+            applicability: Applicability::Automatic,
+        }
+    }
+
+    /// Create a new [`Fix`] with [automatic applicability](Applicability::Automatic) from multiple [`Edit`] elements.
+    pub fn automatic_edits(edit: Edit, rest: impl IntoIterator<Item = Edit>) -> Self {
+        Self {
+            edits: std::iter::once(edit).chain(rest.into_iter()).collect(),
+            applicability: Applicability::Automatic,
+        }
+    }
+
+    /// Create a new [`Fix`] with [suggested applicability](Applicability::Suggested) from an [`Edit`] element.
+    pub fn suggested(edit: Edit) -> Self {
+        Self {
+            edits: vec![edit],
+            applicability: Applicability::Suggested,
+        }
+    }
+
+    /// Create a new [`Fix`] with [suggested applicability](Applicability::Suggested) from multiple [`Edit`] elements.
+    pub fn suggested_edits(edit: Edit, rest: impl IntoIterator<Item = Edit>) -> Self {
+        Self {
+            edits: std::iter::once(edit).chain(rest.into_iter()).collect(),
+            applicability: Applicability::Suggested,
+        }
+    }
+
+    /// Create a new [`Fix`] with [manual applicability](Applicability::Manual) from an [`Edit`] element.
+    pub fn manual(edit: Edit) -> Self {
+        Self {
+            edits: vec![edit],
+            applicability: Applicability::Manual,
+        }
+    }
+
+    /// Create a new [`Fix`] with [manual applicability](Applicability::Manual) from multiple [`Edit`] elements.
+    pub fn manual_edits(edit: Edit, rest: impl IntoIterator<Item = Edit>) -> Self {
+        Self {
+            edits: std::iter::once(edit).chain(rest.into_iter()).collect(),
+            applicability: Applicability::Manual,
         }
     }
 
@@ -37,4 +119,8 @@ impl Fix {
     pub fn into_edits(self) -> Vec<Edit> {
         self.edits
     }
+
+    pub fn applicability(&self) -> Applicability {
+        self.applicability
+    }
 }

crates/ruff_diagnostics/src/lib.rs

@@ -1,6 +1,6 @@
 pub use diagnostic::{Diagnostic, DiagnosticKind};
 pub use edit::Edit;
-pub use fix::Fix;
+pub use fix::{Applicability, Fix};
 pub use violation::{AlwaysAutofixableViolation, AutofixKind, Violation};
 
 mod diagnostic;