Error if nursery rules are selected without preview (#9683)

Extends #9682 to error if the nursery selector is used or nursery rules
are selected without preview.

Part of #7992 — we will remove this in 0.3.0 instead so we can provide
nice errors in 0.2.0.
# Conflicts:
#	crates/ruff/tests/integration_test.rs
#	crates/ruff_workspace/src/configuration.rs

crates/ruff/tests/integration_test.rs

@@ -857,45 +857,44 @@ fn nursery_all() {
 
 #[test]
 fn nursery_direct() {
-    // Should warn that the nursery rule is selected without preview flag but still
-    // include the diagnostic
+    // Should fail when a nursery rule is selected without the preview flag
+    // Before Ruff v0.2.0 this would warn
     let mut cmd = RuffCheck::default()
         .args(["--select", "RUF912", "--output-format=concise"])
         .build();
     assert_cmd_snapshot!(cmd, @r###"
     success: false
-    exit_code: 1
+    exit_code: 2
     ----- stdout -----
-    -:1:1: RUF912 Hey this is a nursery test rule.
-    Found 1 error.
 
     ----- stderr -----
-    warning: Selection of nursery rule `RUF912` without the `--preview` flag is deprecated.
+    ruff failed
+      Cause: Selection of unstable rule `RUF912` without the `--preview` flag is not allowed.
     "###);
 }
 
 #[test]
 fn nursery_group_selector() {
-    // Only nursery rules should be detected e.g. RUF912
+    // The NURSERY selector is removed but parses in the CLI for a nicer error message
+    // Before Ruff v0.2.0 this would warn
     let mut cmd = RuffCheck::default()
         .args(["--select", "NURSERY", "--output-format=concise"])
         .build();
     assert_cmd_snapshot!(cmd, @r###"
     success: false
-    exit_code: 1
+    exit_code: 2
     ----- stdout -----
-    -:1:1: CPY001 Missing copyright notice at top of file
-    -:1:1: RUF912 Hey this is a nursery test rule.
-    Found 2 errors.
 
     ----- stderr -----
-    warning: The `NURSERY` selector has been deprecated. Use the `--preview` flag instead.
+    ruff failed
+      Cause: The `NURSERY` selector was removed. Use the `--preview` flag instead.
     "###);
 }
 
 #[test]
 fn nursery_group_selector_preview_enabled() {
-    // A warning should be displayed due to deprecated selector usage
+    // When preview mode is enabled, we shouldn't suggest using the `--preview` flag.
+    // Before Ruff v0.2.0 this would warn
     let mut cmd = RuffCheck::default()
         .args(["--select", "NURSERY", "--preview"])
         .build();
@@ -906,7 +905,7 @@ fn nursery_group_selector_preview_enabled() {
 
     ----- stderr -----
     ruff failed
-      Cause: The `NURSERY` selector is deprecated and cannot be used with preview mode enabled.
+      Cause: The `NURSERY` selector was removed. Unstable rules should be selected individually or by their respective groups.
     "###);
 }
 

crates/ruff_workspace/src/configuration.rs

@@ -887,10 +887,12 @@ impl LintConfiguration {
             for (kind, selector) in selection.selectors_by_kind() {
                 #[allow(deprecated)]
                 if matches!(selector, RuleSelector::Nursery) {
-                    if preview.mode.is_enabled() {
-                        return Err(anyhow!("The `NURSERY` selector is deprecated and cannot be used with preview mode enabled."));
-                    }
-                    warn_user_once!("The `NURSERY` selector has been deprecated. Use the `--preview` flag instead.");
+                    let suggestion = if preview.mode.is_disabled() {
+                        " Use the `--preview` flag instead."
+                    } else {
+                        " Unstable rules should be selected individually or by their respective groups."
+                    };
+                    return Err(anyhow!("The `NURSERY` selector was removed.{suggestion}"));
                 };
 
                 // Only warn for the following selectors if used to enable rules
@@ -928,9 +930,24 @@ impl LintConfiguration {
             );
         }
 
-        for selection in deprecated_nursery_selectors {
-            let (prefix, code) = selection.prefix_and_code();
-            warn_user!("Selection of nursery rule `{prefix}{code}` without the `--preview` flag is deprecated.",);
+        let deprecated_nursery_selectors = deprecated_nursery_selectors.iter().collect::<Vec<_>>();
+        match deprecated_nursery_selectors.as_slice() {
+            [] => (),
+            [selection] => {
+                let (prefix, code) = selection.prefix_and_code();
+                return Err(anyhow!("Selection of unstable rule `{prefix}{code}` without the `--preview` flag is not allowed."));
+            }
+            [..] => {
+                let mut message = "Selection of unstable rules without the `--preview` flag is not allowed. Enable preview or remove selection of:".to_string();
+                for selection in deprecated_nursery_selectors {
+                    let (prefix, code) = selection.prefix_and_code();
+                    message.push_str("\n\t- ");
+                    message.push_str(prefix);
+                    message.push_str(code);
+                }
+                message.push('\n');
+                return Err(anyhow!(message));
+            }
         }
 
         for selection in ignored_preview_selectors {
@@ -1363,52 +1380,6 @@ mod tests {
     use ruff_linter::RuleSelector;
     use std::str::FromStr;
 
-    const NURSERY_RULES: &[Rule] = &[
-        Rule::MissingCopyrightNotice,
-        Rule::IndentationWithInvalidMultiple,
-        Rule::NoIndentedBlock,
-        Rule::UnexpectedIndentation,
-        Rule::IndentationWithInvalidMultipleComment,
-        Rule::NoIndentedBlockComment,
-        Rule::UnexpectedIndentationComment,
-        Rule::OverIndented,
-        Rule::WhitespaceAfterOpenBracket,
-        Rule::WhitespaceBeforeCloseBracket,
-        Rule::WhitespaceBeforePunctuation,
-        Rule::WhitespaceBeforeParameters,
-        Rule::MultipleSpacesBeforeOperator,
-        Rule::MultipleSpacesAfterOperator,
-        Rule::TabBeforeOperator,
-        Rule::TabAfterOperator,
-        Rule::MissingWhitespaceAroundOperator,
-        Rule::MissingWhitespaceAroundArithmeticOperator,
-        Rule::MissingWhitespaceAroundBitwiseOrShiftOperator,
-        Rule::MissingWhitespaceAroundModuloOperator,
-        Rule::MissingWhitespace,
-        Rule::MultipleSpacesAfterComma,
-        Rule::TabAfterComma,
-        Rule::UnexpectedSpacesAroundKeywordParameterEquals,
-        Rule::MissingWhitespaceAroundParameterEquals,
-        Rule::TooFewSpacesBeforeInlineComment,
-        Rule::NoSpaceAfterInlineComment,
-        Rule::NoSpaceAfterBlockComment,
-        Rule::MultipleLeadingHashesForBlockComment,
-        Rule::MultipleSpacesAfterKeyword,
-        Rule::MultipleSpacesBeforeKeyword,
-        Rule::TabAfterKeyword,
-        Rule::TabBeforeKeyword,
-        Rule::MissingWhitespaceAfterKeyword,
-        Rule::CompareToEmptyString,
-        Rule::NoSelfUse,
-        Rule::EqWithoutHash,
-        Rule::BadDunderMethodName,
-        Rule::RepeatedAppend,
-        Rule::DeleteFullSlice,
-        Rule::CheckAndRemoveFromSet,
-        Rule::QuadraticListSummation,
-        Rule::NurseryTestRule,
-    ];
-
     const PREVIEW_RULES: &[Rule] = &[
         Rule::AndOrTernary,
         Rule::AssignmentInAssert,
@@ -1811,9 +1782,8 @@ mod tests {
 
     #[test]
     fn nursery_select_code() -> Result<()> {
-        // Backwards compatible behavior allows selection of nursery rules with their exact code
-        // when preview is disabled
-        let actual = resolve_rules(
+        // We do not allow selection of nursery rules when preview is disabled
+        assert!(resolve_rules(
             [RuleSelection {
                 select: Some(vec![Flake8Copyright::_001.into()]),
                 ..RuleSelection::default()
@@ -1822,9 +1792,8 @@ mod tests {
                 mode: PreviewMode::Disabled,
                 ..PreviewOptions::default()
             }),
-        )?;
-        let expected = RuleSet::from_rule(Rule::MissingCopyrightNotice);
-        assert_eq!(actual, expected);
+        )
+        .is_err());
 
         let actual = resolve_rules(
             [RuleSelection {
@@ -1843,10 +1812,9 @@ mod tests {
 
     #[test]
     #[allow(deprecated)]
-    fn select_nursery() -> Result<()> {
-        // Backwards compatible behavior allows selection of nursery rules with the nursery selector
-        // when preview is disabled
-        let actual = resolve_rules(
+    fn select_nursery() {
+        // We no longer allow use of the NURSERY selector and should error in both cases
+        assert!(resolve_rules(
             [RuleSelection {
                 select: Some(vec![RuleSelector::Nursery]),
                 ..RuleSelection::default()
@@ -1855,11 +1823,8 @@ mod tests {
                 mode: PreviewMode::Disabled,
                 ..PreviewOptions::default()
             }),
-        )?;
-        let expected = RuleSet::from_rules(NURSERY_RULES);
-        assert_eq!(actual, expected);
-
-        // When preview is enabled, use of NURSERY is banned
+        )
+        .is_err());
         assert!(resolve_rules(
             [RuleSelection {
                 select: Some(vec![RuleSelector::Nursery]),
@@ -1871,8 +1836,6 @@ mod tests {
             }),
         )
         .is_err());
-
-        Ok(())
     }
 
     #[test]

docs/preview.md

@@ -143,12 +143,3 @@ In our previous example, `--select` with `ALL` `HYP`, `HYP0`, or `HYP00` would n
 rule will need to be selected with its exact code, e.g. `--select ALL,HYP001`.
 
 If preview mode is not enabled, this setting has no effect.
-
-## Legacy behavior
-
-Before the preview mode was introduced, new rules were added in a "nursery" category that required selection of
-rules with their exact codes — similar to if `explicit-preview-rules` is enabled.
-
-The nursery category has been deprecated and all rules in the nursery are now considered to be in preview.
-For backwards compatibility, nursery rules are selectable with their exact codes without enabling preview mode.
-However, this behavior will display a warning and support will be removed in a future release.