Stabilize adding future import via config option (#20277)

Introduced in #19100. Removed gating, updated tests, removed warning(s),
and updated documentation.

crates/ruff/tests/lint.rs

@@ -5780,28 +5780,6 @@ match 42:  # invalid-syntax
     Ok(())
 }
 
-#[test]
-fn future_annotations_preview_warning() {
-    assert_cmd_snapshot!(
-        Command::new(get_cargo_bin(BIN_NAME))
-            .args(STDIN_BASE_OPTIONS)
-            .args(["--config", "lint.future-annotations = true"])
-            .args(["--select", "F"])
-            .arg("--no-preview")
-            .arg("-")
-            .pass_stdin("1"),
-        @r"
-    success: true
-    exit_code: 0
-    ----- stdout -----
-    All checks passed!
-
-    ----- stderr -----
-    warning: The `lint.future-annotations` setting will have no effect because `preview` is disabled
-    ",
-    );
-}
-
 #[test]
 fn up045_nested_optional_flatten_all() {
     let contents = "\

crates/ruff_linter/src/preview.rs

@@ -207,11 +207,6 @@ pub(crate) const fn is_safe_super_call_with_parameters_fix_enabled(
     settings.preview.is_enabled()
 }
 
-// https://github.com/astral-sh/ruff/pull/19100
-pub(crate) const fn is_add_future_annotations_imports_enabled(settings: &LinterSettings) -> bool {
-    settings.preview.is_enabled()
-}
-
 // https://github.com/astral-sh/ruff/pull/19851
 pub(crate) const fn is_maxsplit_without_separator_fix_enabled(settings: &LinterSettings) -> bool {
     settings.preview.is_enabled()

crates/ruff_linter/src/rules/flake8_type_checking/helpers.rs

@@ -66,7 +66,7 @@ impl TypingReference {
             }
 
             // prefer `from __future__ import annotations` to quoting
-            if settings.future_annotations()
+            if settings.future_annotations
                 && !reference.in_typing_only_annotation()
                 && reference.in_runtime_evaluated_annotation()
             {

crates/ruff_linter/src/rules/flake8_type_checking/mod.rs

@@ -14,7 +14,6 @@ mod tests {
     use test_case::test_case;
 
     use crate::registry::{Linter, Rule};
-    use crate::settings::types::PreviewMode;
     use crate::test::{test_path, test_snippet};
     use crate::{assert_diagnostics, settings};
 
@@ -86,7 +85,6 @@ mod tests {
             Path::new("flake8_type_checking").join(path).as_path(),
             &settings::LinterSettings {
                 future_annotations: true,
-                preview: PreviewMode::Enabled,
                 // also enable quoting annotations to check the interaction. the future import
                 // should take precedence.
                 flake8_type_checking: super::settings::Settings {

crates/ruff_linter/src/rules/flake8_type_checking/rules/typing_only_runtime_import.rs

@@ -38,6 +38,13 @@ use crate::{Fix, FixAvailability, Violation};
 /// [`lint.flake8-type-checking.runtime-evaluated-decorators`] settings to mark them
 /// as such.
 ///
+/// If [`lint.future-annotations`] is set to `true`, `from __future__ import
+/// annotations` will be added if doing so would enable an import to be
+/// moved into an `if TYPE_CHECKING:` block. This takes precedence over the
+/// [`lint.flake8-type-checking.quote-annotations`] setting described above if
+/// both settings are enabled.
+///
+///
 /// ## Example
 /// ```python
 /// from __future__ import annotations
@@ -63,14 +70,6 @@ use crate::{Fix, FixAvailability, Violation};
 ///     return len(sized)
 /// ```
 ///
-///
-/// ## Preview
-/// If [`lint.future-annotations`] is set to `true`, `from __future__ import
-/// annotations` will be added if doing so would enable an import to be moved into an `if
-/// TYPE_CHECKING:` block. This takes precedence over the
-/// [`lint.flake8-type-checking.quote-annotations`] setting described above if both settings are
-/// enabled.
-///
 /// ## Options
 /// - `lint.flake8-type-checking.quote-annotations`
 /// - `lint.flake8-type-checking.runtime-evaluated-base-classes`
@@ -122,6 +121,12 @@ impl Violation for TypingOnlyFirstPartyImport {
 /// [`lint.flake8-type-checking.runtime-evaluated-decorators`] settings to mark them
 /// as such.
 ///
+/// If [`lint.future-annotations`] is set to `true`, `from __future__ import
+/// annotations` will be added if doing so would enable an import to be
+/// moved into an `if TYPE_CHECKING:` block. This takes precedence over the
+/// [`lint.flake8-type-checking.quote-annotations`] setting described above if
+/// both settings are enabled.
+///
 /// ## Example
 /// ```python
 /// from __future__ import annotations
@@ -147,13 +152,6 @@ impl Violation for TypingOnlyFirstPartyImport {
 ///     return len(df)
 /// ```
 ///
-/// ## Preview
-/// If [`lint.future-annotations`] is set to `true`, `from __future__ import
-/// annotations` will be added if doing so would enable an import to be moved into an `if
-/// TYPE_CHECKING:` block. This takes precedence over the
-/// [`lint.flake8-type-checking.quote-annotations`] setting described above if both settings are
-/// enabled.
-///
 /// ## Options
 /// - `lint.flake8-type-checking.quote-annotations`
 /// - `lint.flake8-type-checking.runtime-evaluated-base-classes`
@@ -205,6 +203,12 @@ impl Violation for TypingOnlyThirdPartyImport {
 /// [`lint.flake8-type-checking.runtime-evaluated-decorators`] settings to mark them
 /// as such.
 ///
+/// If [`lint.future-annotations`] is set to `true`, `from __future__ import
+/// annotations` will be added if doing so would enable an import to be
+/// moved into an `if TYPE_CHECKING:` block. This takes precedence over the
+/// [`lint.flake8-type-checking.quote-annotations`] setting described above if
+/// both settings are enabled.
+///
 /// ## Example
 /// ```python
 /// from __future__ import annotations
@@ -230,15 +234,6 @@ impl Violation for TypingOnlyThirdPartyImport {
 ///     return str(path)
 /// ```
 ///
-/// ## Preview
-///
-/// When [preview](https://docs.astral.sh/ruff/preview/) is enabled, if
-/// [`lint.future-annotations`] is set to `true`, `from __future__ import
-/// annotations` will be added if doing so would enable an import to be moved into an `if
-/// TYPE_CHECKING:` block. This takes precedence over the
-/// [`lint.flake8-type-checking.quote-annotations`] setting described above if both settings are
-/// enabled.
-///
 /// ## Options
 /// - `lint.flake8-type-checking.quote-annotations`
 /// - `lint.flake8-type-checking.runtime-evaluated-base-classes`
@@ -287,7 +282,7 @@ pub(crate) fn typing_only_runtime_import(
 
         // If we can't add a `__future__` import and in un-strict mode, don't flag typing-only
         // imports that are implicitly loaded by way of a valid runtime import.
-        if !checker.settings().future_annotations()
+        if !checker.settings().future_annotations
             && !checker.settings().flake8_type_checking.strict
             && runtime_imports
                 .iter()

crates/ruff_linter/src/rules/pyupgrade/mod.rs

@@ -147,7 +147,6 @@ mod tests {
         let diagnostics = test_path(
             Path::new("pyupgrade").join(path).as_path(),
             &settings::LinterSettings {
-                preview: PreviewMode::Enabled,
                 future_annotations: true,
                 ..settings::LinterSettings::for_rule(rule_code)
             },

crates/ruff_linter/src/rules/pyupgrade/rules/quoted_annotation.rs

@@ -102,7 +102,7 @@ impl AlwaysFixableViolation for QuotedAnnotation {
 
 /// UP037
 pub(crate) fn quoted_annotation(checker: &Checker, annotation: &str, range: TextRange) {
-    let add_future_import = checker.settings().future_annotations()
+    let add_future_import = checker.settings().future_annotations
         && checker.semantic().in_runtime_evaluated_annotation();
 
     if !(checker.semantic().in_typing_only_annotation() || add_future_import) {

crates/ruff_linter/src/rules/ruff/mod.rs

@@ -649,7 +649,6 @@ mod tests {
         let diagnostics = test_path(
             Path::new("ruff").join(path).as_path(),
             &settings::LinterSettings {
-                preview: PreviewMode::Enabled,
                 future_annotations: true,
                 unresolved_target_version: PythonVersion::PY39.into(),
                 ..settings::LinterSettings::for_rule(rule_code)

crates/ruff_linter/src/rules/ruff/rules/implicit_optional.rs

@@ -19,6 +19,10 @@ use crate::rules::ruff::typing::type_hint_explicitly_allows_none;
 /// Checks for the use of implicit `Optional` in type annotations when the
 /// default parameter value is `None`.
 ///
+/// If [`lint.future-annotations`] is set to `true`, `from __future__ import
+/// annotations` will be added if doing so would allow using the `|` operator on
+/// a Python version before 3.10.
+///
 /// ## Why is this bad?
 /// Implicit `Optional` is prohibited by [PEP 484]. It is confusing and
 /// inconsistent with the rest of the type system.
@@ -73,12 +77,6 @@ use crate::rules::ruff::typing::type_hint_explicitly_allows_none;
 /// - `target-version`
 /// - `lint.future-annotations`
 ///
-/// ## Preview
-///
-/// When [preview] is enabled, if [`lint.future-annotations`] is set to `true`,
-/// `from __future__ import annotations` will be added if doing so would allow using the `|`
-/// operator on a Python version before 3.10.
-///
 /// ## Fix safety
 ///
 /// This fix is always marked as unsafe because it can change the behavior of code that relies on
@@ -217,7 +215,7 @@ pub(crate) fn implicit_optional(checker: &Checker, parameters: &Parameters) {
             };
 
             let conversion_type = if checker.target_version() >= PythonVersion::PY310
-                || checker.settings().future_annotations()
+                || checker.settings().future_annotations
             {
                 ConversionType::BinOpOr
             } else {

crates/ruff_linter/src/settings/mod.rs

@@ -475,11 +475,6 @@ impl LinterSettings {
             .is_match(path)
             .map_or(self.unresolved_target_version, TargetVersion::from)
     }
-
-    pub fn future_annotations(&self) -> bool {
-        // TODO(brent) we can just access the field directly once this is stabilized.
-        self.future_annotations && crate::preview::is_add_future_annotations_imports_enabled(self)
-    }
 }
 
 impl Default for LinterSettings {

crates/ruff_workspace/src/configuration.rs

@@ -257,12 +257,6 @@ impl Configuration {
         conflicting_import_settings(&isort, &flake8_import_conventions)?;
 
         let future_annotations = lint.future_annotations.unwrap_or_default();
-        if lint_preview.is_disabled() && future_annotations {
-            warn_user_once!(
-                "The `lint.future-annotations` setting will have no effect \
-                    because `preview` is disabled"
-            );
-        }
 
         Ok(Settings {
             cache_dir: self

crates/ruff_workspace/src/options.rs

@@ -537,8 +537,6 @@ pub struct LintOptions {
     /// For example, `TC001`, `TC002`, and `TC003` can move more imports into `TYPE_CHECKING` blocks
     /// if `__future__` annotations are enabled.
     ///
-    /// This setting is currently in [preview](https://docs.astral.sh/ruff/preview/) and requires
-    /// preview mode to be enabled to have any effect.
     #[option(
         default = "false",
         value_type = "bool",

ruff.schema.json

@@ -2291,7 +2291,7 @@
           ]
         },
         "future-annotations": {
-          "description": "Whether to allow rules to add `from __future__ import annotations` in cases where this would simplify a fix or enable a new diagnostic.\n\nFor example, `TC001`, `TC002`, and `TC003` can move more imports into `TYPE_CHECKING` blocks if `__future__` annotations are enabled.\n\nThis setting is currently in [preview](https://docs.astral.sh/ruff/preview/) and requires preview mode to be enabled to have any effect.",
+          "description": "Whether to allow rules to add `from __future__ import annotations` in cases where this would simplify a fix or enable a new diagnostic.\n\nFor example, `TC001`, `TC002`, and `TC003` can move more imports into `TYPE_CHECKING` blocks if `__future__` annotations are enabled.",
           "type": [
             "boolean",
             "null"