Deprecate preserve import granularity option

It didn't do anything (behaved like `item`), as with `enforceGranularity = false` (which is the default), the style of the current file is always preferred, regardless of the setting.

We could make it fail when the setting is `preserve` and the current file's style could not be detected, but that makes little sense.

It is a bit weird that the default is `crate` but `preserve` falls back to `item`, however that was the previous behavior.

Author: ChayimFriedman2

src/tools/rust-analyzer/crates/ide-db/src/imports/insert_use.rs

@@ -27,9 +27,6 @@ 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.
@@ -174,7 +171,7 @@ fn insert_use_with_alias_option(
         ImportGranularity::Crate => Some(MergeBehavior::Crate),
         ImportGranularity::Module => Some(MergeBehavior::Module),
         ImportGranularity::One => Some(MergeBehavior::One),
-        ImportGranularity::Item | ImportGranularity::Preserve => None,
+        ImportGranularity::Item => None,
     };
     if !cfg.enforce_granularity {
         let file_granularity = guess_granularity_from_scope(scope);

src/tools/rust-analyzer/crates/ide-diagnostics/src/lib.rs

@@ -253,7 +253,7 @@ impl DiagnosticsConfig {
             style_lints: true,
             snippet_cap: SnippetCap::new(true),
             insert_use: InsertUseConfig {
-                granularity: ImportGranularity::Preserve,
+                granularity: ImportGranularity::Item,
                 enforce_granularity: false,
                 prefix_kind: PrefixKind::Plain,
                 group: false,

src/tools/rust-analyzer/crates/rust-analyzer/src/config.rs

@@ -1944,8 +1944,9 @@ impl Config {
     fn insert_use_config(&self, source_root: Option<SourceRootId>) -> InsertUseConfig {
         InsertUseConfig {
             granularity: match self.imports_granularity_group(source_root) {
-                ImportGranularityDef::Preserve => ImportGranularity::Preserve,
-                ImportGranularityDef::Item => ImportGranularity::Item,
+                ImportGranularityDef::Item | ImportGranularityDef::Preserve => {
+                    ImportGranularity::Item
+                }
                 ImportGranularityDef::Crate => ImportGranularity::Crate,
                 ImportGranularityDef::Module => ImportGranularity::Module,
                 ImportGranularityDef::One => ImportGranularity::One,
@@ -3504,13 +3505,23 @@ fn field_props(field: &str, ty: &str, doc: &[&str], default: &str) -> serde_json
         },
         "ImportGranularityDef" => set! {
             "type": "string",
-            "enum": ["preserve", "crate", "module", "item", "one"],
-            "enumDescriptions": [
-                "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.",
-                "Merge all imports into a single use statement as long as they have the same visibility and attributes."
+            "anyOf": [
+                {
+                    "enum": ["crate", "module", "item", "one"],
+                    "enumDescriptions": [
+                        "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.",
+                        "Merge all imports into a single use statement as long as they have the same visibility and attributes."
+                    ],
+                },
+                {
+                    "enum": ["preserve"],
+                    "enumDescriptions": [
+                        "Deprecated - unless `enforceGranularity` is `true`, the style of the current file is preferred over this setting. Behaves like `item`.",
+                    ],
+                    "deprecated": true,
+                }
             ],
         },
         "ImportPrefixDef" => set! {

src/tools/rust-analyzer/editors/code/package.json

@@ -2009,19 +2009,30 @@
                         "markdownDescription": "How imports should be grouped into use statements.",
                         "default": "crate",
                         "type": "string",
-                        "enum": [
-                            "preserve",
-                            "crate",
-                            "module",
-                            "item",
-                            "one"
-                        ],
-                        "enumDescriptions": [
-                            "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.",
-                            "Merge all imports into a single use statement as long as they have the same visibility and attributes."
+                        "anyOf": [
+                            {
+                                "enum": [
+                                    "crate",
+                                    "module",
+                                    "item",
+                                    "one"
+                                ],
+                                "enumDescriptions": [
+                                    "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.",
+                                    "Merge all imports into a single use statement as long as they have the same visibility and attributes."
+                                ]
+                            },
+                            {
+                                "enum": [
+                                    "preserve"
+                                ],
+                                "enumDescriptions": [
+                                    "Deprecated - unless `enforceGranularity` is `true`, the style of the current file is preferred over this setting. Behaves like `item`."
+                                ],
+                                "deprecated": true
+                            }
                         ]
                     }
                 }