`arbitrary_source_item_ordering`: Make alphabetic ordering in module item groups optional (#13718)

From feedback to the `arbitrary_source_item_ordering` lint after its
inclusion in clippy 1.82, making alphabetic ordering within module item
groups has turned out to be the most requested improvement. With this
improvement, it is possible to make the lint perform certain top-level
structural checks on modules (e.g. use statements and module inclusions
at the top), but still leaving everything else up to the developer.

Implements parts of the suggestions from #13675. A catch-all-group is
still to be implemented.

changelog: [`arbitrary_source_item_ordering`]: Make alphabetic ordering
in module item groups optional (off by default)

26 files changed, 871 insertions, 129 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 51441ab9fc0..00323da7745 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6372,6 +6372,7 @@ Released 2018-09-13
 [`min-ident-chars-threshold`]: https://doc.rust-lang.org/clippy/lint_configuration.html#min-ident-chars-threshold
 [`missing-docs-in-crate-items`]: https://doc.rust-lang.org/clippy/lint_configuration.html#missing-docs-in-crate-items
 [`module-item-order-groupings`]: https://doc.rust-lang.org/clippy/lint_configuration.html#module-item-order-groupings
+[`module-items-ordered-within-groupings`]: https://doc.rust-lang.org/clippy/lint_configuration.html#module-items-ordered-within-groupings
 [`msrv`]: https://doc.rust-lang.org/clippy/lint_configuration.html#msrv
 [`pass-by-value-size-limit`]: https://doc.rust-lang.org/clippy/lint_configuration.html#pass-by-value-size-limit
 [`pub-underscore-fields-behavior`]: https://doc.rust-lang.org/clippy/lint_configuration.html#pub-underscore-fields-behavior
diff --git a/book/src/lint_configuration.md b/book/src/lint_configuration.md
index 28b613ea329..3cd70ed18b5 100644
--- a/book/src/lint_configuration.md
+++ b/book/src/lint_configuration.md
@@ -744,6 +744,19 @@ The named groupings of different source item kinds within modules.
 * [`arbitrary_source_item_ordering`](https://rust-lang.github.io/rust-clippy/master/index.html#arbitrary_source_item_ordering)
 
 
+## `module-items-ordered-within-groupings`
+Whether the items within module groups should be ordered alphabetically or not.
+
+This option can be configured to "all", "none", or a list of specific grouping names that should be checked
+(e.g. only "enums").
+
+**Default Value:** `"none"`
+
+---
+**Affected lints:**
+* [`arbitrary_source_item_ordering`](https://rust-lang.github.io/rust-clippy/master/index.html#arbitrary_source_item_ordering)
+
+
 ## `msrv`
 The minimum rust version that the project supports. Defaults to the `rust-version` field in `Cargo.toml`
 
diff --git a/clippy_config/src/conf.rs b/clippy_config/src/conf.rs
index a61acbaa96b..75f68d0dc5f 100644
--- a/clippy_config/src/conf.rs
+++ b/clippy_config/src/conf.rs
@@ -3,14 +3,17 @@ use crate::types::{
     DisallowedPath, DisallowedPathWithoutReplacement, MacroMatcher, MatchLintBehaviour, PubUnderscoreFieldsBehaviour,
     Rename, SourceItemOrdering, SourceItemOrderingCategory, SourceItemOrderingModuleItemGroupings,
     SourceItemOrderingModuleItemKind, SourceItemOrderingTraitAssocItemKind, SourceItemOrderingTraitAssocItemKinds,
+    SourceItemOrderingWithinModuleItemGroupings,
 };
 use clippy_utils::msrvs::Msrv;
+use itertools::Itertools;
 use rustc_errors::Applicability;
 use rustc_session::Session;
 use rustc_span::edit_distance::edit_distance;
 use rustc_span::{BytePos, Pos, SourceFile, Span, SyntaxContext};
 use serde::de::{IgnoredAny, IntoDeserializer, MapAccess, Visitor};
 use serde::{Deserialize, Deserializer, Serialize};
+use std::collections::HashMap;
 use std::fmt::{Debug, Display, Formatter};
 use std::ops::Range;
 use std::path::PathBuf;
@@ -79,6 +82,7 @@ const DEFAULT_SOURCE_ITEM_ORDERING: &[SourceItemOrderingCategory] = {
 #[derive(Default)]
 struct TryConf {
     conf: Conf,
+    value_spans: HashMap<String, Range<usize>>,
     errors: Vec<ConfError>,
     warnings: Vec<ConfError>,
 }
@@ -87,6 +91,7 @@ impl TryConf {
     fn from_toml_error(file: &SourceFile, error: &toml::de::Error) -> Self {
         Self {
             conf: Conf::default(),
+            value_spans: HashMap::default(),
             errors: vec![ConfError::from_toml(file, error)],
             warnings: vec![],
         }
@@ -210,6 +215,7 @@ macro_rules! define_Conf {
             }
 
             fn visit_map<V>(self, mut map: V) -> Result<Self::Value, V::Error> where V: MapAccess<'de> {
+                let mut value_spans = HashMap::new();
                 let mut errors = Vec::new();
                 let mut warnings = Vec::new();
                 $(let mut $name = None;)*
@@ -232,6 +238,7 @@ macro_rules! define_Conf {
                                     }
                                     None => {
                                         $name = Some(value);
+                                        value_spans.insert(name.get_ref().as_str().to_string(), value_span);
                                         // $new_conf is the same as one of the defined `$name`s, so
                                         // this variable is defined in line 2 of this function.
                                         $(match $new_conf {
@@ -250,7 +257,7 @@ macro_rules! define_Conf {
                     }
                 }
                 let conf = Conf { $($name: $name.unwrap_or_else(defaults::$name),)* };
-                Ok(TryConf { conf, errors, warnings })
+                Ok(TryConf { conf, value_spans, errors, warnings })
             }
         }
 
@@ -596,6 +603,13 @@ define_Conf! {
     /// The named groupings of different source item kinds within modules.
     #[lints(arbitrary_source_item_ordering)]
     module_item_order_groupings: SourceItemOrderingModuleItemGroupings = DEFAULT_MODULE_ITEM_ORDERING_GROUPS.into(),
+    /// Whether the items within module groups should be ordered alphabetically or not.
+    ///
+    /// This option can be configured to "all", "none", or a list of specific grouping names that should be checked
+    /// (e.g. only "enums").
+    #[lints(arbitrary_source_item_ordering)]
+    module_items_ordered_within_groupings: SourceItemOrderingWithinModuleItemGroupings =
+        SourceItemOrderingWithinModuleItemGroupings::None,
     /// The minimum rust version that the project supports. Defaults to the `rust-version` field in `Cargo.toml`
     #[default_text = "current version"]
     #[lints(
@@ -815,6 +829,36 @@ fn deserialize(file: &SourceFile) -> TryConf {
                 &mut conf.conf.allow_renamed_params_for,
                 DEFAULT_ALLOWED_TRAITS_WITH_RENAMED_PARAMS,
             );
+
+            // Confirms that the user has not accidentally configured ordering requirements for groups that
+            // aren't configured.
+            if let SourceItemOrderingWithinModuleItemGroupings::Custom(groupings) =
+                &conf.conf.module_items_ordered_within_groupings
+            {
+                for grouping in groupings {
+                    if !conf.conf.module_item_order_groupings.is_grouping(grouping) {
+                        // Since this isn't fixable by rustfix, don't emit a `Suggestion`. This just adds some useful
+                        // info for the user instead.
+
+                        let names = conf.conf.module_item_order_groupings.grouping_names();
+                        let suggestion = suggest_candidate(grouping, names.iter().map(String::as_str))
+                            .map(|s| format!(" perhaps you meant `{s}`?"))
+                            .unwrap_or_default();
+                        let names = names.iter().map(|s| format!("`{s}`")).join(", ");
+                        let message = format!(
+                            "unknown ordering group: `{grouping}` was not specified in `module-items-ordered-within-groupings`,{suggestion} expected one of: {names}"
+                        );
+
+                        let span = conf
+                            .value_spans
+                            .get("module_item_order_groupings")
+                            .cloned()
+                            .unwrap_or_default();
+                        conf.errors.push(ConfError::spanned(file, message, None, span));
+                    }
+                }
+            }
+
             // TODO: THIS SHOULD BE TESTED, this comment will be gone soon
             if conf.conf.allowed_idents_below_min_chars.iter().any(|e| e == "..") {
                 conf.conf
@@ -860,6 +904,7 @@ impl Conf {
 
         let TryConf {
             mut conf,
+            value_spans: _,
             errors,
             warnings,
         } = match path {
@@ -950,17 +995,10 @@ impl serde::de::Error for FieldError {
             }
         }
 
-        let suggestion = expected
-            .iter()
-            .filter_map(|expected| {
-                let dist = edit_distance(field, expected, 4)?;
-                Some((dist, expected))
-            })
-            .min_by_key(|&(dist, _)| dist)
-            .map(|(_, suggestion)| Suggestion {
-                message: "perhaps you meant",
-                suggestion,
-            });
+        let suggestion = suggest_candidate(field, expected).map(|suggestion| Suggestion {
+            message: "perhaps you meant",
+            suggestion,
+        });
 
         Self { error: msg, suggestion }
     }
@@ -998,6 +1036,22 @@ fn calculate_dimensions(fields: &[&str]) -> (usize, Vec<usize>) {
     (rows, column_widths)
 }
 
+/// Given a user-provided value that couldn't be matched to a known option, finds the most likely
+/// candidate among candidates that the user might have meant.
+fn suggest_candidate<'a, I>(value: &str, candidates: I) -> Option<&'a str>
+where
+    I: IntoIterator<Item = &'a str>,
+{
+    candidates
+        .into_iter()
+        .filter_map(|expected| {
+            let dist = edit_distance(value, expected, 4)?;
+            Some((dist, expected))
+        })
+        .min_by_key(|&(dist, _)| dist)
+        .map(|(_, suggestion)| suggestion)
+}
+
 #[cfg(test)]
 mod tests {
     use serde::de::IgnoredAny;
diff --git a/clippy_config/src/types.rs b/clippy_config/src/types.rs
index c72291e9799..8faac9ecffe 100644
--- a/clippy_config/src/types.rs
+++ b/clippy_config/src/types.rs
@@ -305,6 +305,7 @@ impl SourceItemOrderingModuleItemKind {
 pub struct SourceItemOrderingModuleItemGroupings {
     groups: Vec<(String, Vec<SourceItemOrderingModuleItemKind>)>,
     lut: HashMap<SourceItemOrderingModuleItemKind, usize>,
+    back_lut: HashMap<SourceItemOrderingModuleItemKind, String>,
 }
 
 impl SourceItemOrderingModuleItemGroupings {
@@ -320,6 +321,30 @@ impl SourceItemOrderingModuleItemGroupings {
         lut
     }
 
+    fn build_back_lut(
+        groups: &[(String, Vec<SourceItemOrderingModuleItemKind>)],
+    ) -> HashMap<SourceItemOrderingModuleItemKind, String> {
+        let mut lut = HashMap::new();
+        for (group_name, items) in groups {
+            for item in items {
+                lut.insert(item.clone(), group_name.clone());
+            }
+        }
+        lut
+    }
+
+    pub fn grouping_name_of(&self, item: &SourceItemOrderingModuleItemKind) -> Option<&String> {
+        self.back_lut.get(item)
+    }
+
+    pub fn grouping_names(&self) -> Vec<String> {
+        self.groups.iter().map(|(name, _)| name.clone()).collect()
+    }
+
+    pub fn is_grouping(&self, grouping: &str) -> bool {
+        self.groups.iter().any(|(g, _)| g == grouping)
+    }
+
     pub fn module_level_order_of(&self, item: &SourceItemOrderingModuleItemKind) -> Option<usize> {
         self.lut.get(item).copied()
     }
@@ -330,7 +355,8 @@ impl From<&[(&str, &[SourceItemOrderingModuleItemKind])]> for SourceItemOrdering
         let groups: Vec<(String, Vec<SourceItemOrderingModuleItemKind>)> =
             value.iter().map(|item| (item.0.to_string(), item.1.to_vec())).collect();
         let lut = Self::build_lut(&groups);
-        Self { groups, lut }
+        let back_lut = Self::build_back_lut(&groups);
+        Self { groups, lut, back_lut }
     }
 }
 
@@ -348,6 +374,7 @@ impl<'de> Deserialize<'de> for SourceItemOrderingModuleItemGroupings {
         let groups = Vec::<(String, Vec<SourceItemOrderingModuleItemKind>)>::deserialize(deserializer)?;
         let items_total: usize = groups.iter().map(|(_, v)| v.len()).sum();
         let lut = Self::build_lut(&groups);
+        let back_lut = Self::build_back_lut(&groups);
 
         let mut expected_items = SourceItemOrderingModuleItemKind::all_variants();
         for item in lut.keys() {
@@ -370,7 +397,7 @@ impl<'de> Deserialize<'de> for SourceItemOrderingModuleItemGroupings {
                 ));
             }
 
-            Ok(Self { groups, lut })
+            Ok(Self { groups, lut, back_lut })
         } else if items_total != all_items.len() {
             Err(de::Error::custom(format!(
                 "Some module item kinds were configured more than once, or were missing, in the source ordering configuration. \
@@ -482,6 +509,83 @@ impl Serialize for SourceItemOrderingTraitAssocItemKinds {
     }
 }
 
+/// Describes which specific groupings should have their items ordered
+/// alphabetically.
+///
+/// This is separate from defining and enforcing groupings. For example,
+/// defining enums are grouped before structs still allows for an enum B to be
+/// placed before an enum A. Only when enforcing ordering within the grouping,
+/// will it be checked if A is placed before B.
+#[derive(Clone, Debug)]
+pub enum SourceItemOrderingWithinModuleItemGroupings {
+    /// All groupings should have their items ordered.
+    All,
+
+    /// None of the groupings should have their order checked.
+    None,
+
+    /// Only the specified groupings should have their order checked.
+    Custom(Vec<String>),
+}
+
+impl SourceItemOrderingWithinModuleItemGroupings {
+    pub fn ordered_within(&self, grouping_name: &String) -> bool {
+        match self {
+            SourceItemOrderingWithinModuleItemGroupings::All => true,
+            SourceItemOrderingWithinModuleItemGroupings::None => false,
+            SourceItemOrderingWithinModuleItemGroupings::Custom(groups) => groups.contains(grouping_name),
+        }
+    }
+}
+
+/// Helper struct for deserializing the [`SourceItemOrderingWithinModuleItemGroupings`].
+#[derive(Deserialize)]
+#[serde(untagged)]
+enum StringOrVecOfString {
+    String(String),
+    Vec(Vec<String>),
+}
+
+impl<'de> Deserialize<'de> for SourceItemOrderingWithinModuleItemGroupings {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let description = "The available options for configuring an ordering within module item groups are: \
+                    \"all\", \"none\", or a list of module item group names \
+                    (as configured with the `module-item-order-groupings` configuration option).";
+
+        match StringOrVecOfString::deserialize(deserializer) {
+            Ok(StringOrVecOfString::String(preset)) if preset == "all" => {
+                Ok(SourceItemOrderingWithinModuleItemGroupings::All)
+            },
+            Ok(StringOrVecOfString::String(preset)) if preset == "none" => {
+                Ok(SourceItemOrderingWithinModuleItemGroupings::None)
+            },
+            Ok(StringOrVecOfString::String(preset)) => Err(de::Error::custom(format!(
+                "Unknown configuration option: {preset}.\n{description}"
+            ))),
+            Ok(StringOrVecOfString::Vec(groupings)) => {
+                Ok(SourceItemOrderingWithinModuleItemGroupings::Custom(groupings))
+            },
+            Err(e) => Err(de::Error::custom(format!("{e}\n{description}"))),
+        }
+    }
+}
+
+impl Serialize for SourceItemOrderingWithinModuleItemGroupings {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: ser::Serializer,
+    {
+        match self {
+            SourceItemOrderingWithinModuleItemGroupings::All => serializer.serialize_str("all"),
+            SourceItemOrderingWithinModuleItemGroupings::None => serializer.serialize_str("none"),
+            SourceItemOrderingWithinModuleItemGroupings::Custom(vec) => vec.serialize(serializer),
+        }
+    }
+}
+
 // these impls are never actually called but are used by the various config options that default to
 // empty lists
 macro_rules! unimplemented_serialize {
diff --git a/clippy_lints/src/arbitrary_source_item_ordering.rs b/clippy_lints/src/arbitrary_source_item_ordering.rs
index c0ae4960e10..cf4fe45936c 100644
--- a/clippy_lints/src/arbitrary_source_item_ordering.rs
+++ b/clippy_lints/src/arbitrary_source_item_ordering.rs
@@ -2,6 +2,7 @@ use clippy_config::Conf;
 use clippy_config::types::{
     SourceItemOrderingCategory, SourceItemOrderingModuleItemGroupings, SourceItemOrderingModuleItemKind,
     SourceItemOrderingTraitAssocItemKind, SourceItemOrderingTraitAssocItemKinds,
+    SourceItemOrderingWithinModuleItemGroupings,
 };
 use clippy_utils::diagnostics::span_lint_and_note;
 use rustc_hir::{
@@ -36,7 +37,7 @@ declare_clippy_lint! {
     /// 2. Individual ordering rules per item kind.
     ///
     /// The item kinds that can be linted are:
-    /// - Module (with customized groupings, alphabetical within)
+    /// - Module (with customized groupings, alphabetical within - configurable)
     /// - Trait (with customized order of associated items, alphabetical within)
     /// - Enum, Impl, Struct (purely alphabetical)
     ///
@@ -57,8 +58,31 @@ declare_clippy_lint! {
     /// | `PascalCase`       | "ty_alias", "opaque_ty", "enum", "struct", "union", "trait", "trait_alias", "impl" |
     /// | `lower_snake_case` | "fn"                 |
     ///
+    /// The groups' names are arbitrary and can be changed to suit the
+    /// conventions that should be enforced for a specific project.
+    ///
     /// All item kinds must be accounted for to create an enforceable linting
-    /// rule set.
+    /// rule set. Following are some example configurations that may be useful.
+    ///
+    /// Example: *module inclusions and use statements to be at the top*
+    ///
+    /// ```toml
+    /// module-item-order-groupings = [
+    ///     [ "modules", [ "extern_crate", "mod", "foreign_mod" ], ],
+    ///     [ "use", [ "use", ], ],
+    ///     [ "everything_else", [ "macro", "global_asm", "static", "const", "ty_alias", "enum", "struct", "union", "trait", "trait_alias", "impl", "fn", ], ],
+    /// ]
+    /// ```
+    ///
+    /// Example: *only consts and statics should be alphabetically ordered*
+    ///
+    /// It is also possible to configure a selection of module item groups that
+    /// should be ordered alphabetically. This may be useful if for example
+    /// statics and consts should be ordered, but the rest should be left open.
+    ///
+    /// ```toml
+    /// module-items-ordered-within-groupings = ["UPPER_SNAKE_CASE"]
+    /// ```
     ///
     /// ### Known Problems
     ///
@@ -143,6 +167,7 @@ pub struct ArbitrarySourceItemOrdering {
     enable_ordering_for_struct: bool,
     enable_ordering_for_trait: bool,
     module_item_order_groupings: SourceItemOrderingModuleItemGroupings,
+    module_items_ordered_within_groupings: SourceItemOrderingWithinModuleItemGroupings,
 }
 
 impl ArbitrarySourceItemOrdering {
@@ -157,6 +182,7 @@ impl ArbitrarySourceItemOrdering {
             enable_ordering_for_struct: conf.source_item_ordering.contains(&Struct),
             enable_ordering_for_trait: conf.source_item_ordering.contains(&Trait),
             module_item_order_groupings: conf.module_item_order_groupings.clone(),
+            module_items_ordered_within_groupings: conf.module_items_ordered_within_groupings.clone(),
         }
     }
 
@@ -191,7 +217,7 @@ impl ArbitrarySourceItemOrdering {
         );
     }
 
-    fn lint_member_item<T: LintContext>(cx: &T, item: &Item<'_>, before_item: &Item<'_>) {
+    fn lint_member_item<T: LintContext>(cx: &T, item: &Item<'_>, before_item: &Item<'_>, msg: &'static str) {
         let span = if item.ident.as_str().is_empty() {
             &item.span
         } else {
@@ -215,14 +241,7 @@ impl ArbitrarySourceItemOrdering {
             return;
         }
 
-        span_lint_and_note(
-            cx,
-            ARBITRARY_SOURCE_ITEM_ORDERING,
-            *span,
-            "incorrect ordering of items (must be alphabetically ordered)",
-            Some(*before_span),
-            note,
-        );
+        span_lint_and_note(cx, ARBITRARY_SOURCE_ITEM_ORDERING, *span, msg, Some(*before_span), note);
     }
 
     /// Produces a linting warning for incorrectly ordered trait items.
@@ -402,6 +421,7 @@ impl<'tcx> LateLintPass<'tcx> for ArbitrarySourceItemOrdering {
             }
 
             let item_kind = convert_module_item_kind(&item.kind);
+            let grouping_name = self.module_item_order_groupings.grouping_name_of(&item_kind);
             let module_level_order = self
                 .module_item_order_groupings
                 .module_level_order_of(&item_kind)
@@ -411,13 +431,27 @@ impl<'tcx> LateLintPass<'tcx> for ArbitrarySourceItemOrdering {
                 use std::cmp::Ordering; // Better legibility.
                 match module_level_order.cmp(&cur_t.order) {
                     Ordering::Less => {
-                        Self::lint_member_item(cx, item, cur_t.item);
+                        Self::lint_member_item(
+                            cx,
+                            item,
+                            cur_t.item,
+                            "incorrect ordering of items (module item groupings specify another order)",
+                        );
                     },
                     Ordering::Equal if item_kind == SourceItemOrderingModuleItemKind::Use => {
                         // Skip ordering use statements, as these should be ordered by rustfmt.
                     },
-                    Ordering::Equal if cur_t.name > get_item_name(item) => {
-                        Self::lint_member_item(cx, item, cur_t.item);
+                    Ordering::Equal
+                        if (grouping_name.is_some_and(|grouping_name| {
+                            self.module_items_ordered_within_groupings.ordered_within(grouping_name)
+                        }) && cur_t.name > get_item_name(item)) =>
+                    {
+                        Self::lint_member_item(
+                            cx,
+                            item,
+                            cur_t.item,
+                            "incorrect ordering of items (must be alphabetically ordered)",
+                        );
                     },
                     Ordering::Equal | Ordering::Greater => {
                         // Nothing to do in this case, they're already in the right order.
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_4/clippy.toml b/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_4/clippy.toml
new file mode 100644
index 00000000000..baf7041138f
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_4/clippy.toml
@@ -0,0 +1 @@
+module-items-ordered-within-groupings = true
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_5/clippy.toml b/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_5/clippy.toml
new file mode 100644
index 00000000000..1fa80c73012
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_5/clippy.toml
@@ -0,0 +1 @@
+module-items-ordered-within-groupings = ["madules"]
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_6/clippy.toml b/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_6/clippy.toml
new file mode 100644
index 00000000000..cee857a155b
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_6/clippy.toml
@@ -0,0 +1 @@
+module-items-ordered-within-groupings = ["entirely garbled"]
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/default_exp/clippy.toml b/tests/ui-toml/arbitrary_source_item_ordering/default_exp/clippy.toml
index ddca5cfa577..af3aa1cc62a 100644
--- a/tests/ui-toml/arbitrary_source_item_ordering/default_exp/clippy.toml
+++ b/tests/ui-toml/arbitrary_source_item_ordering/default_exp/clippy.toml
@@ -9,4 +9,4 @@ module-item-order-groupings = [
     ["PascalCase", ["ty_alias", "enum", "struct", "union", "trait", "trait_alias", "impl"]],
     ["lower_snake_case", ["fn"]]
 ]
-
+module-items-ordered-within-groupings = "none"
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ord_in_2/clippy.toml b/tests/ui-toml/arbitrary_source_item_ordering/ord_in_2/clippy.toml
new file mode 100644
index 00000000000..fd961c82d6f
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ord_in_2/clippy.toml
@@ -0,0 +1 @@
+module-items-ordered-within-groupings = ["PascalCase"]
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ord_in_3/clippy.toml b/tests/ui-toml/arbitrary_source_item_ordering/ord_in_3/clippy.toml
new file mode 100644
index 00000000000..de2a7307eca
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ord_in_3/clippy.toml
@@ -0,0 +1,2 @@
+source-item-ordering = ["module"]
+module-items-ordered-within-groupings = ["PascalCase"]
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ord_within/clippy.toml b/tests/ui-toml/arbitrary_source_item_ordering/ord_within/clippy.toml
new file mode 100644
index 00000000000..e7640efde10
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ord_within/clippy.toml
@@ -0,0 +1 @@
+module-items-ordered-within-groupings = "all"
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_4.stderr b/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_4.stderr
new file mode 100644
index 00000000000..c38c54ffeb0
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_4.stderr
@@ -0,0 +1,8 @@
+error: error reading Clippy's configuration file: data did not match any variant of untagged enum StringOrVecOfString  The available options for configuring an ordering within module item groups are: "all", "none", or a list of module item group names (as configured with the `module-item-order-groupings` configuration option).
+  --> $DIR/tests/ui-toml/arbitrary_source_item_ordering/bad_conf_4/clippy.toml:1:41
+   |
+LL | module-items-ordered-within-groupings = true
+   |                                         ^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_5.stderr b/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_5.stderr
new file mode 100644
index 00000000000..7b1dafb6d0d
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_5.stderr
@@ -0,0 +1,4 @@
+error: error reading Clippy's configuration file: unknown ordering group: `madules` was not specified in `module-items-ordered-within-groupings`, perhaps you meant `modules`? expected one of: `modules`, `use`, `macros`, `global_asm`, `UPPER_SNAKE_CASE`, `PascalCase`, `lower_snake_case`
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_6.stderr b/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_6.stderr
new file mode 100644
index 00000000000..996cabeeed4
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.bad_conf_6.stderr
@@ -0,0 +1,4 @@
+error: error reading Clippy's configuration file: unknown ordering group: `entirely garbled` was not specified in `module-items-ordered-within-groupings`, expected one of: `modules`, `use`, `macros`, `global_asm`, `UPPER_SNAKE_CASE`, `PascalCase`, `lower_snake_case`
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.rs b/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.rs
index 05eb40506db..b43791521cb 100644
--- a/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.rs
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ordering_good.rs
@@ -1,15 +1,21 @@
 //@aux-build:../../ui/auxiliary/proc_macros.rs
-//@revisions: default default_exp bad_conf_1 bad_conf_2 bad_conf_3
+//@revisions: default default_exp bad_conf_1 bad_conf_2 bad_conf_3 bad_conf_4 bad_conf_5 bad_conf_6
 //@[default] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/default
 //@[default_exp] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/default_exp
 //@[bad_conf_1] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/bad_conf_1
 //@[bad_conf_2] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/bad_conf_2
 //@[bad_conf_3] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/bad_conf_3
+//@[bad_conf_4] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/bad_conf_4
+//@[bad_conf_5] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/bad_conf_5
+//@[bad_conf_6] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/bad_conf_6
 //@[default] check-pass
 //@[default_exp] check-pass
 //@[bad_conf_1] error-in-other-file:
 //@[bad_conf_2] error-in-other-file:
 //@[bad_conf_3] error-in-other-file:
+//@[bad_conf_4] error-in-other-file:
+//@[bad_conf_5] error-in-other-file:
+//@[bad_conf_6] error-in-other-file:
 
 #![allow(dead_code)]
 #![warn(clippy::arbitrary_source_item_ordering)]
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.default.stderr b/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.default.stderr
index 3605952bddc..50567e32b1b 100644
--- a/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.default.stderr
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.default.stderr
@@ -1,223 +1,160 @@
-error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:22:14
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:26:14
    |
 LL | use std::rc::Weak;
    |              ^^^^
    |
 note: should be placed before `SNAKE_CASE`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:20:7
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:23:7
    |
 LL | const SNAKE_CASE: &str = "zzzzzzzz";
    |       ^^^^^^^^^^
    = note: `-D clippy::arbitrary-source-item-ordering` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::arbitrary_source_item_ordering)]`
 
-error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:67:1
-   |
-LL | / impl CloneSelf for StructOrdered {
-LL | |
-LL | |     fn clone_self(&self) -> Self {
-LL | |         Self {
-...  |
-LL | | }
-   | |_^
-   |
-note: should be placed before the following item
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:57:1
-   |
-LL | / impl Default for StructOrdered {
-LL | |     fn default() -> Self {
-LL | |         Self {
-LL | |             a: true,
-...  |
-LL | | }
-   | |_^
-
-error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:145:7
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:149:7
    |
 LL | const ZIS_SHOULD_BE_REALLY_EARLY: () = ();
    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: should be placed before `TraitUnorderedItemKinds`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:132:7
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:136:7
    |
 LL | trait TraitUnorderedItemKinds {
    |       ^^^^^^^^^^^^^^^^^^^^^^^
 
-error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:163:1
-   |
-LL | impl BasicEmptyTrait for StructOrdered {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: should be placed before the following item
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:148:1
-   |
-LL | / impl TraitUnordered for StructUnordered {
-LL | |     const A: bool = false;
-LL | |     const C: bool = false;
-LL | |     const B: bool = false;
-...  |
-LL | | }
-   | |_^
-
-error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:184:5
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:188:5
    |
 LL | mod this_is_in_the_wrong_position {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: should be placed before `main`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:179:4
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:183:4
    |
 LL | fn main() {
    |    ^^^^
 
-error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:194:7
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:198:7
    |
 LL | const ZIS_SHOULD_BE_EVEN_EARLIER: () = ();
    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 note: should be placed before `ZisShouldBeBeforeZeMainFn`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:192:8
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:196:8
    |
 LL | struct ZisShouldBeBeforeZeMainFn;
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:12:11
-   |
-LL |     const AFTER: i8 = 0;
-   |           ^^^^^
-   |
-note: should be placed before `BEFORE`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:10:11
-   |
-LL |     const BEFORE: i8 = 0;
-   |           ^^^^^^
-
-error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:40:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:44:5
    |
 LL |     B,
    |     ^
    |
 note: should be placed before `C`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:39:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:43:5
    |
 LL |     C,
    |     ^
 
 error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:92:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:96:5
    |
 LL |     b: bool,
    |     ^
    |
 note: should be placed before `c`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:91:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:95:5
    |
 LL |     c: bool,
    |     ^
 
 error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:101:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:105:5
    |
 LL |     b: bool,
    |     ^
    |
 note: should be placed before `c`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:100:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:104:5
    |
 LL |     c: bool,
    |     ^
 
 error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:121:11
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:125:11
    |
 LL |     const B: bool;
    |           ^
    |
 note: should be placed before `C`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:120:11
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:124:11
    |
 LL |     const C: bool;
    |           ^
 
 error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:128:8
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:132:8
    |
 LL |     fn b();
    |        ^
    |
 note: should be placed before `c`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:127:8
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:131:8
    |
 LL |     fn c();
    |        ^
 
 error: incorrect ordering of trait items (defined order: [Const, Type, Fn])
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:135:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:139:5
    |
 LL |     const A: bool;
    |     ^^^^^^^^^^^^^^
    |
 note: should be placed before `SomeType`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:133:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:137:5
    |
 LL |     type SomeType;
    |     ^^^^^^^^^^^^^^
 
 error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:151:11
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:155:11
    |
 LL |     const B: bool = false;
    |           ^
    |
 note: should be placed before `C`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:150:11
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:154:11
    |
 LL |     const C: bool = false;
    |           ^
 
 error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:158:8
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:162:8
    |
 LL |     fn b() {}
    |        ^
    |
 note: should be placed before `c`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:157:8
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:161:8
    |
 LL |     fn c() {}
    |        ^
 
 error: incorrect ordering of impl items (defined order: [Const, Type, Fn])
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:169:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:173:5
    |
 LL |     const A: bool = false;
    |     ^^^^^^^^^^^^^^^^^^^^^^
    |
 note: should be placed before `SomeType`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:167:5
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:171:5
    |
 LL |     type SomeType = ();
    |     ^^^^^^^^^^^^^^^^^^^
 
-error: incorrect ordering of items (must be alphabetically ordered)
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:187:11
-   |
-LL |     const A: i8 = 1;
-   |           ^
-   |
-note: should be placed before `C`
-  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:186:11
-   |
-LL |     const C: i8 = 0;
-   |           ^
-
-error: aborting due to 17 previous errors
+error: aborting due to 13 previous errors
 
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.default_exp.stderr b/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.default_exp.stderr
new file mode 100644
index 00000000000..50567e32b1b
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.default_exp.stderr
@@ -0,0 +1,160 @@
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:26:14
+   |
+LL | use std::rc::Weak;
+   |              ^^^^
+   |
+note: should be placed before `SNAKE_CASE`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:23:7
+   |
+LL | const SNAKE_CASE: &str = "zzzzzzzz";
+   |       ^^^^^^^^^^
+   = note: `-D clippy::arbitrary-source-item-ordering` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::arbitrary_source_item_ordering)]`
+
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:149:7
+   |
+LL | const ZIS_SHOULD_BE_REALLY_EARLY: () = ();
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before `TraitUnorderedItemKinds`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:136:7
+   |
+LL | trait TraitUnorderedItemKinds {
+   |       ^^^^^^^^^^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:188:5
+   |
+LL | mod this_is_in_the_wrong_position {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before `main`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:183:4
+   |
+LL | fn main() {
+   |    ^^^^
+
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:198:7
+   |
+LL | const ZIS_SHOULD_BE_EVEN_EARLIER: () = ();
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before `ZisShouldBeBeforeZeMainFn`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:196:8
+   |
+LL | struct ZisShouldBeBeforeZeMainFn;
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:44:5
+   |
+LL |     B,
+   |     ^
+   |
+note: should be placed before `C`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:43:5
+   |
+LL |     C,
+   |     ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:96:5
+   |
+LL |     b: bool,
+   |     ^
+   |
+note: should be placed before `c`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:95:5
+   |
+LL |     c: bool,
+   |     ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:105:5
+   |
+LL |     b: bool,
+   |     ^
+   |
+note: should be placed before `c`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:104:5
+   |
+LL |     c: bool,
+   |     ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:125:11
+   |
+LL |     const B: bool;
+   |           ^
+   |
+note: should be placed before `C`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:124:11
+   |
+LL |     const C: bool;
+   |           ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:132:8
+   |
+LL |     fn b();
+   |        ^
+   |
+note: should be placed before `c`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:131:8
+   |
+LL |     fn c();
+   |        ^
+
+error: incorrect ordering of trait items (defined order: [Const, Type, Fn])
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:139:5
+   |
+LL |     const A: bool;
+   |     ^^^^^^^^^^^^^^
+   |
+note: should be placed before `SomeType`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:137:5
+   |
+LL |     type SomeType;
+   |     ^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:155:11
+   |
+LL |     const B: bool = false;
+   |           ^
+   |
+note: should be placed before `C`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:154:11
+   |
+LL |     const C: bool = false;
+   |           ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:162:8
+   |
+LL |     fn b() {}
+   |        ^
+   |
+note: should be placed before `c`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:161:8
+   |
+LL |     fn c() {}
+   |        ^
+
+error: incorrect ordering of impl items (defined order: [Const, Type, Fn])
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:173:5
+   |
+LL |     const A: bool = false;
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before `SomeType`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:171:5
+   |
+LL |     type SomeType = ();
+   |     ^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 13 previous errors
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.ord_within.stderr b/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.ord_within.stderr
new file mode 100644
index 00000000000..ae5261dcc6d
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.ord_within.stderr
@@ -0,0 +1,235 @@
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:23:7
+   |
+LL | const SNAKE_CASE: &str = "zzzzzzzz";
+   |       ^^^^^^^^^^
+   |
+note: should be placed before `ZNAKE_CASE`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:22:7
+   |
+LL | const ZNAKE_CASE: &str = "123";
+   |       ^^^^^^^^^^
+   = note: `-D clippy::arbitrary-source-item-ordering` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::arbitrary_source_item_ordering)]`
+
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:26:14
+   |
+LL | use std::rc::Weak;
+   |              ^^^^
+   |
+note: should be placed before `SNAKE_CASE`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:23:7
+   |
+LL | const SNAKE_CASE: &str = "zzzzzzzz";
+   |       ^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:71:1
+   |
+LL | / impl CloneSelf for StructOrdered {
+LL | |
+LL | |     fn clone_self(&self) -> Self {
+LL | |         Self {
+...  |
+LL | | }
+   | |_^
+   |
+note: should be placed before the following item
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:61:1
+   |
+LL | / impl Default for StructOrdered {
+LL | |     fn default() -> Self {
+LL | |         Self {
+LL | |             a: true,
+...  |
+LL | | }
+   | |_^
+
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:149:7
+   |
+LL | const ZIS_SHOULD_BE_REALLY_EARLY: () = ();
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before `TraitUnorderedItemKinds`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:136:7
+   |
+LL | trait TraitUnorderedItemKinds {
+   |       ^^^^^^^^^^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:167:1
+   |
+LL | impl BasicEmptyTrait for StructOrdered {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before the following item
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:152:1
+   |
+LL | / impl TraitUnordered for StructUnordered {
+LL | |     const A: bool = false;
+LL | |     const C: bool = false;
+LL | |     const B: bool = false;
+...  |
+LL | | }
+   | |_^
+
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:188:5
+   |
+LL | mod this_is_in_the_wrong_position {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before `main`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:183:4
+   |
+LL | fn main() {
+   |    ^^^^
+
+error: incorrect ordering of items (module item groupings specify another order)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:198:7
+   |
+LL | const ZIS_SHOULD_BE_EVEN_EARLIER: () = ();
+   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before `ZisShouldBeBeforeZeMainFn`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:196:8
+   |
+LL | struct ZisShouldBeBeforeZeMainFn;
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:14:11
+   |
+LL |     const AFTER: i8 = 0;
+   |           ^^^^^
+   |
+note: should be placed before `BEFORE`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:12:11
+   |
+LL |     const BEFORE: i8 = 0;
+   |           ^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:44:5
+   |
+LL |     B,
+   |     ^
+   |
+note: should be placed before `C`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:43:5
+   |
+LL |     C,
+   |     ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:96:5
+   |
+LL |     b: bool,
+   |     ^
+   |
+note: should be placed before `c`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:95:5
+   |
+LL |     c: bool,
+   |     ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:105:5
+   |
+LL |     b: bool,
+   |     ^
+   |
+note: should be placed before `c`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:104:5
+   |
+LL |     c: bool,
+   |     ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:125:11
+   |
+LL |     const B: bool;
+   |           ^
+   |
+note: should be placed before `C`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:124:11
+   |
+LL |     const C: bool;
+   |           ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:132:8
+   |
+LL |     fn b();
+   |        ^
+   |
+note: should be placed before `c`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:131:8
+   |
+LL |     fn c();
+   |        ^
+
+error: incorrect ordering of trait items (defined order: [Const, Type, Fn])
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:139:5
+   |
+LL |     const A: bool;
+   |     ^^^^^^^^^^^^^^
+   |
+note: should be placed before `SomeType`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:137:5
+   |
+LL |     type SomeType;
+   |     ^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:155:11
+   |
+LL |     const B: bool = false;
+   |           ^
+   |
+note: should be placed before `C`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:154:11
+   |
+LL |     const C: bool = false;
+   |           ^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:162:8
+   |
+LL |     fn b() {}
+   |        ^
+   |
+note: should be placed before `c`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:161:8
+   |
+LL |     fn c() {}
+   |        ^
+
+error: incorrect ordering of impl items (defined order: [Const, Type, Fn])
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:173:5
+   |
+LL |     const A: bool = false;
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   |
+note: should be placed before `SomeType`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:171:5
+   |
+LL |     type SomeType = ();
+   |     ^^^^^^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:191:11
+   |
+LL |     const A: i8 = 1;
+   |           ^
+   |
+note: should be placed before `C`
+  --> tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs:190:11
+   |
+LL |     const C: i8 = 0;
+   |           ^
+
+error: aborting due to 18 previous errors
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs b/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs
index 9e65a9cca0d..90399470d4c 100644
--- a/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs
+++ b/tests/ui-toml/arbitrary_source_item_ordering/ordering_mixed.rs
@@ -1,6 +1,8 @@
 //@aux-build:../../ui/auxiliary/proc_macros.rs
-//@revisions: default
+//@revisions: default default_exp ord_within
 //@[default] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/default
+//@[default_exp] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/default_exp
+//@[ord_within] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/ord_within
 
 #![allow(dead_code)]
 #![warn(clippy::arbitrary_source_item_ordering)]
@@ -10,14 +12,16 @@ mod i_am_just_right {
     const BEFORE: i8 = 0;
 
     const AFTER: i8 = 0;
-    //~^ arbitrary_source_item_ordering
+    //~[ord_within]^ arbitrary_source_item_ordering
 }
 
 // Use statements should not be linted internally - this is normally auto-sorted using rustfmt.
 use std::rc::Rc;
 use std::sync::{Arc, Barrier, RwLock};
 
+const ZNAKE_CASE: &str = "123";
 const SNAKE_CASE: &str = "zzzzzzzz";
+//~[ord_within]^ arbitrary_source_item_ordering
 
 use std::rc::Weak;
 //~^ arbitrary_source_item_ordering
@@ -65,7 +69,7 @@ impl Default for StructOrdered {
 }
 
 impl CloneSelf for StructOrdered {
-    //~^ arbitrary_source_item_ordering
+    //~[ord_within]^ arbitrary_source_item_ordering
     fn clone_self(&self) -> Self {
         Self {
             a: true,
@@ -161,7 +165,7 @@ impl TraitUnordered for StructUnordered {
 
 // Trait impls should be located just after the type they implement it for.
 impl BasicEmptyTrait for StructOrdered {}
-//~^ arbitrary_source_item_ordering
+//~[ord_within]^ arbitrary_source_item_ordering
 
 impl TraitUnorderedItemKinds for StructUnordered {
     type SomeType = ();
@@ -185,7 +189,7 @@ mod this_is_in_the_wrong_position {
     //~^ arbitrary_source_item_ordering
     const C: i8 = 0;
     const A: i8 = 1;
-    //~^ arbitrary_source_item_ordering
+    //~[ord_within]^ arbitrary_source_item_ordering
 }
 
 #[derive(Default, std::clone::Clone)]
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.default.stderr b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.default.stderr
new file mode 100644
index 00000000000..7fc216b30d5
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.default.stderr
@@ -0,0 +1,19 @@
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:35:5
+   |
+LL |     a: bool,
+   |     ^
+   |
+note: should be placed before `b`
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:34:5
+   |
+LL |     b: bool,
+   |     ^
+note: the lint level is defined here
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:32:8
+   |
+LL | #[deny(clippy::arbitrary_source_item_ordering)]
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_in_2.stderr b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_in_2.stderr
new file mode 100644
index 00000000000..1f75f5099ec
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_in_2.stderr
@@ -0,0 +1,36 @@
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:24:8
+   |
+LL | struct OrderedChecked {
+   |        ^^^^^^^^^^^^^^
+   |
+note: should be placed before `Unordered`
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:18:8
+   |
+LL | struct Unordered {
+   |        ^^^^^^^^^
+note: the lint level is defined here
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:9:9
+   |
+LL | #![deny(clippy::arbitrary_source_item_ordering)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:35:5
+   |
+LL |     a: bool,
+   |     ^
+   |
+note: should be placed before `b`
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:34:5
+   |
+LL |     b: bool,
+   |     ^
+note: the lint level is defined here
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:32:8
+   |
+LL | #[deny(clippy::arbitrary_source_item_ordering)]
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_in_3.stderr b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_in_3.stderr
new file mode 100644
index 00000000000..8027f55add6
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_in_3.stderr
@@ -0,0 +1,19 @@
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:24:8
+   |
+LL | struct OrderedChecked {
+   |        ^^^^^^^^^^^^^^
+   |
+note: should be placed before `Unordered`
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:18:8
+   |
+LL | struct Unordered {
+   |        ^^^^^^^^^
+note: the lint level is defined here
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:9:9
+   |
+LL | #![deny(clippy::arbitrary_source_item_ordering)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_within.stderr b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_within.stderr
new file mode 100644
index 00000000000..333a601f6a9
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.ord_within.stderr
@@ -0,0 +1,48 @@
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:24:8
+   |
+LL | struct OrderedChecked {
+   |        ^^^^^^^^^^^^^^
+   |
+note: should be placed before `Unordered`
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:18:8
+   |
+LL | struct Unordered {
+   |        ^^^^^^^^^
+note: the lint level is defined here
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:9:9
+   |
+LL | #![deny(clippy::arbitrary_source_item_ordering)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:45:4
+   |
+LL | fn before_main() {}
+   |    ^^^^^^^^^^^
+   |
+note: should be placed before `main`
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:41:4
+   |
+LL | fn main() {
+   |    ^^^^
+
+error: incorrect ordering of items (must be alphabetically ordered)
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:35:5
+   |
+LL |     a: bool,
+   |     ^
+   |
+note: should be placed before `b`
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:34:5
+   |
+LL |     b: bool,
+   |     ^
+note: the lint level is defined here
+  --> tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs:32:8
+   |
+LL | #[deny(clippy::arbitrary_source_item_ordering)]
+   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+
diff --git a/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs
new file mode 100644
index 00000000000..e32b921dd96
--- /dev/null
+++ b/tests/ui-toml/arbitrary_source_item_ordering/selective_ordering.rs
@@ -0,0 +1,46 @@
+//@aux-build:../../ui/auxiliary/proc_macros.rs
+//@revisions: default ord_within ord_in_2 ord_in_3
+//@[default] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/default
+//@[ord_within] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/ord_within
+//@[ord_in_2] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/ord_in_2
+//@[ord_in_3] rustc-env:CLIPPY_CONF_DIR=tests/ui-toml/arbitrary_source_item_ordering/ord_in_3
+
+#![allow(dead_code)]
+#![deny(clippy::arbitrary_source_item_ordering)]
+
+#[allow(clippy::arbitrary_source_item_ordering)]
+struct Ordered {
+    a: bool,
+    b: bool,
+}
+
+#[allow(clippy::arbitrary_source_item_ordering)]
+struct Unordered {
+    b: bool,
+    a: bool,
+}
+
+#[deny(clippy::arbitrary_source_item_ordering)]
+struct OrderedChecked {
+    //~[ord_within]^ arbitrary_source_item_ordering
+    //~[ord_in_2]| arbitrary_source_item_ordering
+    //~[ord_in_3]| arbitrary_source_item_ordering
+    a: bool,
+    b: bool,
+}
+
+#[deny(clippy::arbitrary_source_item_ordering)]
+struct UnorderedChecked {
+    b: bool,
+    a: bool,
+    //~[ord_within]^ arbitrary_source_item_ordering
+    //~[default]| arbitrary_source_item_ordering
+    //~[ord_in_2]| arbitrary_source_item_ordering
+}
+
+fn main() {
+    // test code goes here
+}
+
+fn before_main() {}
+//~[ord_within]^ arbitrary_source_item_ordering
diff --git a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
index acfe739277c..fee5b01b689 100644
--- a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
+++ b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
@@ -60,6 +60,7 @@ error: error reading Clippy's configuration file: unknown field `foobar`, expect
            min-ident-chars-threshold
            missing-docs-in-crate-items
            module-item-order-groupings
+           module-items-ordered-within-groupings
            msrv
            pass-by-value-size-limit
            pub-underscore-fields-behavior
@@ -152,6 +153,7 @@ error: error reading Clippy's configuration file: unknown field `barfoo`, expect
            min-ident-chars-threshold
            missing-docs-in-crate-items
            module-item-order-groupings
+           module-items-ordered-within-groupings
            msrv
            pass-by-value-size-limit
            pub-underscore-fields-behavior
@@ -244,6 +246,7 @@ error: error reading Clippy's configuration file: unknown field `allow_mixed_uni
            min-ident-chars-threshold
            missing-docs-in-crate-items
            module-item-order-groupings
+           module-items-ordered-within-groupings
            msrv
            pass-by-value-size-limit
            pub-underscore-fields-behavior