8 files changed, 75 insertions, 38 deletions

diff --git a/crates/ide_assists/src/tests.rs b/crates/ide_assists/src/tests.rs
index 0d3969c36..bb1ca0b3d 100644
--- a/crates/ide_assists/src/tests.rs
+++ b/crates/ide_assists/src/tests.rs
@@ -4,7 +4,10 @@ use expect_test::expect;
 use hir::Semantics;
 use ide_db::{
     base_db::{fixture::WithFixture, FileId, FileRange, SourceDatabaseExt},
-    helpers::{insert_use::InsertUseConfig, merge_imports::MergeBehavior, SnippetCap},
+    helpers::{
+        insert_use::{ImportGranularity, InsertUseConfig},
+        SnippetCap,
+    },
     source_change::FileSystemEdit,
     RootDatabase,
 };
@@ -21,7 +24,7 @@ pub(crate) const TEST_CONFIG: AssistConfig = AssistConfig {
     snippet_cap: SnippetCap::new(true),
     allowed: None,
     insert_use: InsertUseConfig {
-        merge: Some(MergeBehavior::Crate),
+        granularity: ImportGranularity::Crate,
         prefix_kind: hir::PrefixKind::Plain,
         group: true,
     },
diff --git a/crates/ide_completion/src/test_utils.rs b/crates/ide_completion/src/test_utils.rs
index 939fb2d47..b150a5c3f 100644
--- a/crates/ide_completion/src/test_utils.rs
+++ b/crates/ide_completion/src/test_utils.rs
@@ -3,7 +3,10 @@
 use hir::{PrefixKind, Semantics};
 use ide_db::{
     base_db::{fixture::ChangeFixture, FileLoader, FilePosition},
-    helpers::{insert_use::InsertUseConfig, merge_imports::MergeBehavior, SnippetCap},
+    helpers::{
+        insert_use::{ImportGranularity, InsertUseConfig},
+        SnippetCap,
+    },
     RootDatabase,
 };
 use itertools::Itertools;
@@ -20,7 +23,7 @@ pub(crate) const TEST_CONFIG: CompletionConfig = CompletionConfig {
     add_call_argument_snippets: true,
     snippet_cap: SnippetCap::new(true),
     insert_use: InsertUseConfig {
-        merge: Some(MergeBehavior::Crate),
+        granularity: ImportGranularity::Crate,
         prefix_kind: PrefixKind::Plain,
         group: true,
     },
diff --git a/crates/ide_db/src/helpers/insert_use.rs b/crates/ide_db/src/helpers/insert_use.rs
index 55cdc4da3..a4eb31815 100644
--- a/crates/ide_db/src/helpers/insert_use.rs
+++ b/crates/ide_db/src/helpers/insert_use.rs
@@ -15,9 +15,32 @@ use crate::{
 
 pub use hir::PrefixKind;
 
+/// How imports should be grouped into use statements.
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum ImportGranularity {
+    /// Do not change the granularity of any imports and preserve the original structure written by the developer.
+    Preserve,
+    /// Merge imports from the same crate into a single use statement.
+    Crate,
+    /// Merge imports from the same module into a single use statement.
+    Module,
+    /// Flatten imports so that each has its own use statement.
+    Item,
+}
+
+impl ImportGranularity {
+    pub fn merge_behavior(self) -> Option<MergeBehavior> {
+        match self {
+            ImportGranularity::Crate => Some(MergeBehavior::Crate),
+            ImportGranularity::Module => Some(MergeBehavior::Module),
+            ImportGranularity::Preserve | ImportGranularity::Item => None,
+        }
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub struct InsertUseConfig {
-    pub merge: Option<MergeBehavior>,
+    pub granularity: ImportGranularity,
     pub prefix_kind: PrefixKind,
     pub group: bool,
 }
@@ -73,7 +96,7 @@ pub fn insert_use<'a>(scope: &ImportScope, path: ast::Path, cfg: InsertUseConfig
     let use_item =
         make::use_(None, make::use_tree(path.clone(), None, None, false)).clone_for_update();
     // merge into existing imports if possible
-    if let Some(mb) = cfg.merge {
+    if let Some(mb) = cfg.granularity.merge_behavior() {
         for existing_use in scope.as_syntax_node().children().filter_map(ast::Use::cast) {
             if let Some(merged) = try_merge_imports(&existing_use, &use_item, mb) {
                 ted::replace(existing_use.syntax(), merged.syntax());
diff --git a/crates/ide_db/src/helpers/insert_use/tests.rs b/crates/ide_db/src/helpers/insert_use/tests.rs
index 248227d29..f99857a89 100644
--- a/crates/ide_db/src/helpers/insert_use/tests.rs
+++ b/crates/ide_db/src/helpers/insert_use/tests.rs
@@ -21,7 +21,7 @@ use crate::bar::A;
 use self::bar::A;
 use super::bar::A;
 use external_crate2::bar::A;",
-        None,
+        ImportGranularity::Item,
         false,
         false,
     );
@@ -36,7 +36,7 @@ fn insert_not_group_empty() {
         r"use external_crate2::bar::A;
 
 ",
-        None,
+        ImportGranularity::Item,
         false,
         false,
     );
@@ -281,7 +281,7 @@ fn insert_empty_module() {
         r"{
     use foo::bar;
 }",
-        None,
+        ImportGranularity::Item,
         true,
         true,
     )
@@ -635,7 +635,7 @@ fn check(
     path: &str,
     ra_fixture_before: &str,
     ra_fixture_after: &str,
-    mb: Option<MergeBehavior>,
+    granularity: ImportGranularity,
     module: bool,
     group: bool,
 ) {
@@ -651,21 +651,21 @@ fn check(
         .find_map(ast::Path::cast)
         .unwrap();
 
-    insert_use(&file, path, InsertUseConfig { merge: mb, prefix_kind: PrefixKind::Plain, group });
+    insert_use(&file, path, InsertUseConfig { granularity, prefix_kind: PrefixKind::Plain, group });
     let result = file.as_syntax_node().to_string();
     assert_eq_text!(ra_fixture_after, &result);
 }
 
 fn check_crate(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Crate), false, true)
+    check(path, ra_fixture_before, ra_fixture_after, ImportGranularity::Crate, false, true)
 }
 
 fn check_module(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(path, ra_fixture_before, ra_fixture_after, Some(MergeBehavior::Module), false, true)
+    check(path, ra_fixture_before, ra_fixture_after, ImportGranularity::Module, false, true)
 }
 
 fn check_none(path: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
-    check(path, ra_fixture_before, ra_fixture_after, None, false, true)
+    check(path, ra_fixture_before, ra_fixture_after, ImportGranularity::Item, false, true)
 }
 
 fn check_merge_only_fail(ra_fixture0: &str, ra_fixture1: &str, mb: MergeBehavior) {
diff --git a/crates/rust-analyzer/src/config.rs b/crates/rust-analyzer/src/config.rs
index a3866c1ba..e72387257 100644
--- a/crates/rust-analyzer/src/config.rs
+++ b/crates/rust-analyzer/src/config.rs
@@ -12,8 +12,7 @@ use std::{ffi::OsString, iter, path::PathBuf};
 use flycheck::FlycheckConfig;
 use ide::{AssistConfig, CompletionConfig, DiagnosticsConfig, HoverConfig, InlayHintsConfig};
 use ide_db::helpers::{
-    insert_use::{InsertUseConfig, PrefixKind},
-    merge_imports::MergeBehavior,
+    insert_use::{ImportGranularity, InsertUseConfig, PrefixKind},
     SnippetCap,
 };
 use lsp_types::{ClientCapabilities, MarkupKind};
@@ -35,8 +34,9 @@ use crate::{
 config_data! {
     struct ConfigData {
         /// The strategy to use when inserting new imports or merging imports.
+        assist_importGranularity |
         assist_importMergeBehavior |
-        assist_importMergeBehaviour: MergeBehaviorDef  = "\"crate\"",
+        assist_importMergeBehaviour: ImportGranularityDef  = "\"preserve\"",
         /// The path structure for newly inserted paths to use.
         assist_importPrefix: ImportPrefixDef           = "\"plain\"",
         /// Group inserted imports by the [following order](https://rust-analyzer.github.io/manual.html#auto-import). Groups are separated by newlines.
@@ -609,10 +609,11 @@ impl Config {
     }
     fn insert_use_config(&self) -> InsertUseConfig {
         InsertUseConfig {
-            merge: match self.data.assist_importMergeBehavior {
-                MergeBehaviorDef::None => None,
-                MergeBehaviorDef::Crate => Some(MergeBehavior::Crate),
-                MergeBehaviorDef::Module => Some(MergeBehavior::Module),
+            granularity: match self.data.assist_importGranularity {
+                ImportGranularityDef::Preserve => ImportGranularity::Preserve,
+                ImportGranularityDef::Item => ImportGranularity::Item,
+                ImportGranularityDef::Crate => ImportGranularity::Crate,
+                ImportGranularityDef::Module => ImportGranularity::Module,
             },
             prefix_kind: match self.data.assist_importPrefix {
                 ImportPrefixDef::Plain => PrefixKind::Plain,
@@ -717,8 +718,10 @@ enum ManifestOrProjectJson {
 
 #[derive(Deserialize, Debug, Clone)]
 #[serde(rename_all = "snake_case")]
-enum MergeBehaviorDef {
-    None,
+enum ImportGranularityDef {
+    #[serde(alias = "none")]
+    Item,
+    Preserve,
     #[serde(alias = "full")]
     Crate,
     #[serde(alias = "last")]
@@ -737,7 +740,7 @@ macro_rules! _config_data {
     (struct $name:ident {
         $(
             $(#[doc=$doc:literal])*
-            $field:ident $(| $alias:ident)?: $ty:ty = $default:expr,
+            $field:ident $(| $alias:ident)*: $ty:ty = $default:expr,
         )*
     }) => {
         #[allow(non_snake_case)]
@@ -749,7 +752,7 @@ macro_rules! _config_data {
                     $field: get_field(
                         &mut json,
                         stringify!($field),
-                        None$(.or(Some(stringify!($alias))))?,
+                        None$(.or(Some(stringify!($alias))))*,
                         $default,
                     ),
                 )*}
diff --git a/crates/rust-analyzer/src/integrated_benchmarks.rs b/crates/rust-analyzer/src/integrated_benchmarks.rs
index ba2790acb..cd0b8d559 100644
--- a/crates/rust-analyzer/src/integrated_benchmarks.rs
+++ b/crates/rust-analyzer/src/integrated_benchmarks.rs
@@ -13,7 +13,10 @@
 use std::{convert::TryFrom, sync::Arc};
 
 use ide::{Change, CompletionConfig, FilePosition, TextSize};
-use ide_db::helpers::{insert_use::InsertUseConfig, merge_imports::MergeBehavior, SnippetCap};
+use ide_db::helpers::{
+    insert_use::{ImportGranularity, InsertUseConfig},
+    SnippetCap,
+};
 use test_utils::project_root;
 use vfs::{AbsPathBuf, VfsPath};
 
@@ -133,7 +136,7 @@ fn integrated_completion_benchmark() {
             add_call_argument_snippets: true,
             snippet_cap: SnippetCap::new(true),
             insert_use: InsertUseConfig {
-                merge: Some(MergeBehavior::Crate),
+                granularity: ImportGranularity::Crate,
                 prefix_kind: hir::PrefixKind::ByCrate,
                 group: true,
             },
@@ -166,7 +169,7 @@ fn integrated_completion_benchmark() {
             add_call_argument_snippets: true,
             snippet_cap: SnippetCap::new(true),
             insert_use: InsertUseConfig {
-                merge: Some(MergeBehavior::Crate),
+                granularity: ImportGranularity::Crate,
                 prefix_kind: hir::PrefixKind::ByCrate,
                 group: true,
             },
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index 9dec46c78..64d5f9e2e 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -1145,7 +1145,7 @@ mod tests {
 
     use ide::Analysis;
     use ide_db::helpers::{
-        insert_use::{InsertUseConfig, PrefixKind},
+        insert_use::{ImportGranularity, InsertUseConfig, PrefixKind},
         SnippetCap,
     };
 
@@ -1177,7 +1177,7 @@ mod tests {
                     add_call_argument_snippets: true,
                     snippet_cap: SnippetCap::new(true),
                     insert_use: InsertUseConfig {
-                        merge: None,
+                        granularity: ImportGranularity::Item,
                         prefix_kind: PrefixKind::Plain,
                         group: true,
                     },
diff --git a/editors/code/package.json b/editors/code/package.json
index 2e67b6775..81179ff9b 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -385,19 +385,21 @@
                     "markdownDescription": "Optional settings passed to the debug engine. Example: `{ \"lldb\": { \"terminal\":\"external\"} }`"
                 },
                 "$generated-start": false,
-                "rust-analyzer.assist.importMergeBehavior": {
-                    "markdownDescription": "The strategy to use when inserting new imports or merging imports.",
-                    "default": "crate",
+                "rust-analyzer.assist.importGranularity": {
+                    "markdownDescription": "How imports should be grouped into use statements.",
+                    "default": "preserve",
                     "type": "string",
                     "enum": [
-                        "none",
+                        "preserve",
                         "crate",
-                        "module"
+                        "module",
+                        "item"
                     ],
                     "enumDescriptions": [
-                        "Do not merge imports at all.",
-                        "Merge imports from the same crate into a single `use` statement.",
-                        "Merge imports from the same module into a single `use` statement."
+                        "Do not change the granularity of any imports and preserve the original structure written by the developer.",
+                        "Merge imports from the same crate into a single use statement. Conversely, imports from different crates are split into separate statements.",
+                        "Merge imports from the same module into a single use statement. Conversely, imports from different modules are split into separate statements.",
+                        "Flatten imports so that each has its own use statement."
                     ]
                 },
                 "rust-analyzer.assist.importPrefix": {