11 files changed, 518 insertions, 97 deletions

diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index 1c911a8b2..b14f908b7 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -15,6 +15,7 @@ use hir::{
     diagnostics::{Diagnostic as _, DiagnosticCode, DiagnosticSinkBuilder},
     InFile, Semantics,
 };
+use ide_assists::AssistResolveStrategy;
 use ide_db::{base_db::SourceDatabase, RootDatabase};
 use itertools::Itertools;
 use rustc_hash::FxHashSet;
@@ -84,7 +85,7 @@ pub struct DiagnosticsConfig {
 pub(crate) fn diagnostics(
     db: &RootDatabase,
     config: &DiagnosticsConfig,
-    resolve: bool,
+    resolve: &AssistResolveStrategy,
     file_id: FileId,
 ) -> Vec<Diagnostic> {
     let _p = profile::span("diagnostics");
@@ -212,7 +213,7 @@ pub(crate) fn diagnostics(
 fn diagnostic_with_fix<D: DiagnosticWithFix>(
     d: &D,
     sema: &Semantics<RootDatabase>,
-    resolve: bool,
+    resolve: &AssistResolveStrategy,
 ) -> Diagnostic {
     Diagnostic::error(sema.diagnostics_display_range(d.display_source()).range, d.message())
         .with_fix(d.fix(&sema, resolve))
@@ -222,7 +223,7 @@ fn diagnostic_with_fix<D: DiagnosticWithFix>(
 fn warning_with_fix<D: DiagnosticWithFix>(
     d: &D,
     sema: &Semantics<RootDatabase>,
-    resolve: bool,
+    resolve: &AssistResolveStrategy,
 ) -> Diagnostic {
     Diagnostic::hint(sema.diagnostics_display_range(d.display_source()).range, d.message())
         .with_fix(d.fix(&sema, resolve))
@@ -299,6 +300,7 @@ fn unresolved_fix(id: &'static str, label: &str, target: TextRange) -> Assist {
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
+    use ide_assists::AssistResolveStrategy;
     use stdx::trim_indent;
     use test_utils::assert_eq_text;
 
@@ -314,7 +316,11 @@ mod tests {
 
         let (analysis, file_position) = fixture::position(ra_fixture_before);
         let diagnostic = analysis
-            .diagnostics(&DiagnosticsConfig::default(), true, file_position.file_id)
+            .diagnostics(
+                &DiagnosticsConfig::default(),
+                AssistResolveStrategy::All,
+                file_position.file_id,
+            )
             .unwrap()
             .pop()
             .unwrap();
@@ -343,7 +349,11 @@ mod tests {
     fn check_no_fix(ra_fixture: &str) {
         let (analysis, file_position) = fixture::position(ra_fixture);
         let diagnostic = analysis
-            .diagnostics(&DiagnosticsConfig::default(), true, file_position.file_id)
+            .diagnostics(
+                &DiagnosticsConfig::default(),
+                AssistResolveStrategy::All,
+                file_position.file_id,
+            )
             .unwrap()
             .pop()
             .unwrap();
@@ -357,7 +367,9 @@ mod tests {
         let diagnostics = files
             .into_iter()
             .flat_map(|file_id| {
-                analysis.diagnostics(&DiagnosticsConfig::default(), true, file_id).unwrap()
+                analysis
+                    .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::All, file_id)
+                    .unwrap()
             })
             .collect::<Vec<_>>();
         assert_eq!(diagnostics.len(), 0, "unexpected diagnostics:\n{:#?}", diagnostics);
@@ -365,8 +377,9 @@ mod tests {
 
     fn check_expect(ra_fixture: &str, expect: Expect) {
         let (analysis, file_id) = fixture::file(ra_fixture);
-        let diagnostics =
-            analysis.diagnostics(&DiagnosticsConfig::default(), true, file_id).unwrap();
+        let diagnostics = analysis
+            .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::All, file_id)
+            .unwrap();
         expect.assert_debug_eq(&diagnostics)
     }
 
@@ -911,11 +924,13 @@ struct Foo {
 
         let (analysis, file_id) = fixture::file(r#"mod foo;"#);
 
-        let diagnostics = analysis.diagnostics(&config, true, file_id).unwrap();
+        let diagnostics =
+            analysis.diagnostics(&config, AssistResolveStrategy::All, file_id).unwrap();
         assert!(diagnostics.is_empty());
 
-        let diagnostics =
-            analysis.diagnostics(&DiagnosticsConfig::default(), true, file_id).unwrap();
+        let diagnostics = analysis
+            .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::All, file_id)
+            .unwrap();
         assert!(!diagnostics.is_empty());
     }
 
@@ -1022,7 +1037,11 @@ impl TestStruct {
 
         let (analysis, file_position) = fixture::position(input);
         let diagnostics = analysis
-            .diagnostics(&DiagnosticsConfig::default(), true, file_position.file_id)
+            .diagnostics(
+                &DiagnosticsConfig::default(),
+                AssistResolveStrategy::All,
+                file_position.file_id,
+            )
             .unwrap();
         assert_eq!(diagnostics.len(), 1);
 
diff --git a/crates/ide/src/diagnostics/fixes.rs b/crates/ide/src/diagnostics/fixes.rs
index 7be8b3459..15821500f 100644
--- a/crates/ide/src/diagnostics/fixes.rs
+++ b/crates/ide/src/diagnostics/fixes.rs
@@ -8,6 +8,7 @@ use hir::{
     },
     HasSource, HirDisplay, InFile, Semantics, VariantDef,
 };
+use ide_assists::AssistResolveStrategy;
 use ide_db::{
     base_db::{AnchoredPathBuf, FileId},
     source_change::{FileSystemEdit, SourceChange},
@@ -35,11 +36,19 @@ pub(crate) trait DiagnosticWithFix: Diagnostic {
     ///
     /// If `resolve` is false, the edit will be computed later, on demand, and
     /// can be omitted.
-    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist>;
+    fn fix(
+        &self,
+        sema: &Semantics<RootDatabase>,
+        _resolve: &AssistResolveStrategy,
+    ) -> Option<Assist>;
 }
 
 impl DiagnosticWithFix for UnresolvedModule {
-    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
+    fn fix(
+        &self,
+        sema: &Semantics<RootDatabase>,
+        _resolve: &AssistResolveStrategy,
+    ) -> Option<Assist> {
         let root = sema.db.parse_or_expand(self.file)?;
         let unresolved_module = self.decl.to_node(&root);
         Some(fix(
@@ -59,7 +68,11 @@ impl DiagnosticWithFix for UnresolvedModule {
 }
 
 impl DiagnosticWithFix for NoSuchField {
-    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
+    fn fix(
+        &self,
+        sema: &Semantics<RootDatabase>,
+        _resolve: &AssistResolveStrategy,
+    ) -> Option<Assist> {
         let root = sema.db.parse_or_expand(self.file)?;
         missing_record_expr_field_fix(
             &sema,
@@ -70,7 +83,11 @@ impl DiagnosticWithFix for NoSuchField {
 }
 
 impl DiagnosticWithFix for MissingFields {
-    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
+    fn fix(
+        &self,
+        sema: &Semantics<RootDatabase>,
+        _resolve: &AssistResolveStrategy,
+    ) -> Option<Assist> {
         // Note that although we could add a diagnostics to
         // fill the missing tuple field, e.g :
         // `struct A(usize);`
@@ -106,7 +123,11 @@ impl DiagnosticWithFix for MissingFields {
 }
 
 impl DiagnosticWithFix for MissingOkOrSomeInTailExpr {
-    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
+    fn fix(
+        &self,
+        sema: &Semantics<RootDatabase>,
+        _resolve: &AssistResolveStrategy,
+    ) -> Option<Assist> {
         let root = sema.db.parse_or_expand(self.file)?;
         let tail_expr = self.expr.to_node(&root);
         let tail_expr_range = tail_expr.syntax().text_range();
@@ -119,7 +140,11 @@ impl DiagnosticWithFix for MissingOkOrSomeInTailExpr {
 }
 
 impl DiagnosticWithFix for RemoveThisSemicolon {
-    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
+    fn fix(
+        &self,
+        sema: &Semantics<RootDatabase>,
+        _resolve: &AssistResolveStrategy,
+    ) -> Option<Assist> {
         let root = sema.db.parse_or_expand(self.file)?;
 
         let semicolon = self
@@ -139,7 +164,11 @@ impl DiagnosticWithFix for RemoveThisSemicolon {
 }
 
 impl DiagnosticWithFix for IncorrectCase {
-    fn fix(&self, sema: &Semantics<RootDatabase>, resolve: bool) -> Option<Assist> {
+    fn fix(
+        &self,
+        sema: &Semantics<RootDatabase>,
+        resolve: &AssistResolveStrategy,
+    ) -> Option<Assist> {
         let root = sema.db.parse_or_expand(self.file)?;
         let name_node = self.ident.to_node(&root);
 
@@ -149,7 +178,7 @@ impl DiagnosticWithFix for IncorrectCase {
 
         let label = format!("Rename to {}", self.suggested_text);
         let mut res = unresolved_fix("change_case", &label, frange.range);
-        if resolve {
+        if resolve.should_resolve(&res.id) {
             let source_change = rename_with_semantics(sema, file_position, &self.suggested_text);
             res.source_change = Some(source_change.ok().unwrap_or_default());
         }
@@ -159,7 +188,11 @@ impl DiagnosticWithFix for IncorrectCase {
 }
 
 impl DiagnosticWithFix for ReplaceFilterMapNextWithFindMap {
-    fn fix(&self, sema: &Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
+    fn fix(
+        &self,
+        sema: &Semantics<RootDatabase>,
+        _resolve: &AssistResolveStrategy,
+    ) -> Option<Assist> {
         let root = sema.db.parse_or_expand(self.file)?;
         let next_expr = self.next_expr.to_node(&root);
         let next_call = ast::MethodCallExpr::cast(next_expr.syntax().clone())?;
diff --git a/crates/ide/src/diagnostics/unlinked_file.rs b/crates/ide/src/diagnostics/unlinked_file.rs
index 7d39f4fbe..93fd25dea 100644
--- a/crates/ide/src/diagnostics/unlinked_file.rs
+++ b/crates/ide/src/diagnostics/unlinked_file.rs
@@ -5,6 +5,7 @@ use hir::{
     diagnostics::{Diagnostic, DiagnosticCode},
     InFile,
 };
+use ide_assists::AssistResolveStrategy;
 use ide_db::{
     base_db::{FileId, FileLoader, SourceDatabase, SourceDatabaseExt},
     source_change::SourceChange,
@@ -50,7 +51,11 @@ impl Diagnostic for UnlinkedFile {
 }
 
 impl DiagnosticWithFix for UnlinkedFile {
-    fn fix(&self, sema: &hir::Semantics<RootDatabase>, _resolve: bool) -> Option<Assist> {
+    fn fix(
+        &self,
+        sema: &hir::Semantics<RootDatabase>,
+        _resolve: &AssistResolveStrategy,
+    ) -> Option<Assist> {
         // If there's an existing module that could add a `mod` item to include the unlinked file,
         // suggest that as a fix.
 
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 99e45633e..8e5b72044 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -87,7 +87,9 @@ pub use crate::{
     },
 };
 pub use hir::{Documentation, Semantics};
-pub use ide_assists::{Assist, AssistConfig, AssistId, AssistKind};
+pub use ide_assists::{
+    Assist, AssistConfig, AssistId, AssistKind, AssistResolveStrategy, SingleResolve,
+};
 pub use ide_completion::{
     CompletionConfig, CompletionItem, CompletionItemKind, CompletionRelevance, ImportEdit,
     InsertTextFormat,
@@ -518,12 +520,13 @@ impl Analysis {
     pub fn assists(
         &self,
         config: &AssistConfig,
-        resolve: bool,
+        resolve: AssistResolveStrategy,
         frange: FileRange,
     ) -> Cancelable<Vec<Assist>> {
         self.with_db(|db| {
+            let ssr_assists = ssr::ssr_assists(db, &resolve, frange);
             let mut acc = Assist::get(db, config, resolve, frange);
-            ssr::add_ssr_assist(db, &mut acc, resolve, frange);
+            acc.extend(ssr_assists.into_iter());
             acc
         })
     }
@@ -532,10 +535,10 @@ impl Analysis {
     pub fn diagnostics(
         &self,
         config: &DiagnosticsConfig,
-        resolve: bool,
+        resolve: AssistResolveStrategy,
         file_id: FileId,
     ) -> Cancelable<Vec<Diagnostic>> {
-        self.with_db(|db| diagnostics::diagnostics(db, config, resolve, file_id))
+        self.with_db(|db| diagnostics::diagnostics(db, config, &resolve, file_id))
     }
 
     /// Convenience function to return assists + quick fixes for diagnostics
@@ -543,7 +546,7 @@ impl Analysis {
         &self,
         assist_config: &AssistConfig,
         diagnostics_config: &DiagnosticsConfig,
-        resolve: bool,
+        resolve: AssistResolveStrategy,
         frange: FileRange,
     ) -> Cancelable<Vec<Assist>> {
         let include_fixes = match &assist_config.allowed {
@@ -552,17 +555,21 @@ impl Analysis {
         };
 
         self.with_db(|db| {
+            let ssr_assists = ssr::ssr_assists(db, &resolve, frange);
+            let diagnostic_assists = if include_fixes {
+                diagnostics::diagnostics(db, diagnostics_config, &resolve, frange.file_id)
+                    .into_iter()
+                    .filter_map(|it| it.fix)
+                    .filter(|it| it.target.intersect(frange.range).is_some())
+                    .collect()
+            } else {
+                Vec::new()
+            };
+
             let mut res = Assist::get(db, assist_config, resolve, frange);
-            ssr::add_ssr_assist(db, &mut res, resolve, frange);
-
-            if include_fixes {
-                res.extend(
-                    diagnostics::diagnostics(db, diagnostics_config, resolve, frange.file_id)
-                        .into_iter()
-                        .filter_map(|it| it.fix)
-                        .filter(|it| it.target.intersect(frange.range).is_some()),
-                );
-            }
+            res.extend(ssr_assists.into_iter());
+            res.extend(diagnostic_assists.into_iter());
+
             res
         })
     }
diff --git a/crates/ide/src/ssr.rs b/crates/ide/src/ssr.rs
index f3638d928..57ec80261 100644
--- a/crates/ide/src/ssr.rs
+++ b/crates/ide/src/ssr.rs
@@ -2,18 +2,23 @@
 //! assist in ide_assists because that would require the ide_assists crate
 //! depend on the ide_ssr crate.
 
-use ide_assists::{Assist, AssistId, AssistKind, GroupLabel};
+use ide_assists::{Assist, AssistId, AssistKind, AssistResolveStrategy, GroupLabel};
 use ide_db::{base_db::FileRange, label::Label, source_change::SourceChange, RootDatabase};
 
-pub(crate) fn add_ssr_assist(
+pub(crate) fn ssr_assists(
     db: &RootDatabase,
-    base: &mut Vec<Assist>,
-    resolve: bool,
+    resolve: &AssistResolveStrategy,
     frange: FileRange,
-) -> Option<()> {
-    let (match_finder, comment_range) = ide_ssr::ssr_from_comment(db, frange)?;
+) -> Vec<Assist> {
+    let mut ssr_assists = Vec::with_capacity(2);
 
-    let (source_change_for_file, source_change_for_workspace) = if resolve {
+    let (match_finder, comment_range) = match ide_ssr::ssr_from_comment(db, frange) {
+        Some(ssr_data) => ssr_data,
+        None => return ssr_assists,
+    };
+    let id = AssistId("ssr", AssistKind::RefactorRewrite);
+
+    let (source_change_for_file, source_change_for_workspace) = if resolve.should_resolve(&id) {
         let edits = match_finder.edits();
 
         let source_change_for_file = {
@@ -35,16 +40,17 @@ pub(crate) fn add_ssr_assist(
 
     for (label, source_change) in assists.into_iter() {
         let assist = Assist {
-            id: AssistId("ssr", AssistKind::RefactorRewrite),
+            id,
             label: Label::new(label),
             group: Some(GroupLabel("Apply SSR".into())),
             target: comment_range,
             source_change,
         };
 
-        base.push(assist);
+        ssr_assists.push(assist);
     }
-    Some(())
+
+    ssr_assists
 }
 
 #[cfg(test)]
@@ -52,7 +58,7 @@ mod tests {
     use std::sync::Arc;
 
     use expect_test::expect;
-    use ide_assists::Assist;
+    use ide_assists::{Assist, AssistResolveStrategy};
     use ide_db::{
         base_db::{fixture::WithFixture, salsa::Durability, FileRange},
         symbol_index::SymbolsDatabase,
@@ -60,24 +66,14 @@ mod tests {
     };
     use rustc_hash::FxHashSet;
 
-    use super::add_ssr_assist;
+    use super::ssr_assists;
 
-    fn get_assists(ra_fixture: &str, resolve: bool) -> Vec<Assist> {
+    fn get_assists(ra_fixture: &str, resolve: AssistResolveStrategy) -> Vec<Assist> {
         let (mut db, file_id, range_or_offset) = RootDatabase::with_range_or_offset(ra_fixture);
         let mut local_roots = FxHashSet::default();
         local_roots.insert(ide_db::base_db::fixture::WORKSPACE);
         db.set_local_roots_with_durability(Arc::new(local_roots), Durability::HIGH);
-
-        let mut assists = vec![];
-
-        add_ssr_assist(
-            &db,
-            &mut assists,
-            resolve,
-            FileRange { file_id, range: range_or_offset.into() },
-        );
-
-        assists
+        ssr_assists(&db, &resolve, FileRange { file_id, range: range_or_offset.into() })
     }
 
     #[test]
@@ -88,16 +84,13 @@ mod tests {
             // This is foo $0
             fn foo() {}
             "#;
-        let resolve = true;
-
-        let assists = get_assists(ra_fixture, resolve);
+        let assists = get_assists(ra_fixture, AssistResolveStrategy::All);
 
         assert_eq!(0, assists.len());
     }
 
     #[test]
     fn resolve_edits_true() {
-        let resolve = true;
         let assists = get_assists(
             r#"
             //- /lib.rs
@@ -109,7 +102,7 @@ mod tests {
             //- /bar.rs
             fn bar() { 2 }
             "#,
-            resolve,
+            AssistResolveStrategy::All,
         );
 
         assert_eq!(2, assists.len());
@@ -200,7 +193,6 @@ mod tests {
 
     #[test]
     fn resolve_edits_false() {
-        let resolve = false;
         let assists = get_assists(
             r#"
             //- /lib.rs
@@ -212,7 +204,7 @@ mod tests {
             //- /bar.rs
             fn bar() { 2 }
             "#,
-            resolve,
+            AssistResolveStrategy::None,
         );
 
         assert_eq!(2, assists.len());
diff --git a/crates/ide_assists/src/assist_context.rs b/crates/ide_assists/src/assist_context.rs
index 4b0bba2ab..112939948 100644
--- a/crates/ide_assists/src/assist_context.rs
+++ b/crates/ide_assists/src/assist_context.rs
@@ -19,7 +19,9 @@ use syntax::{
 };
 use text_edit::{TextEdit, TextEditBuilder};
 
-use crate::{assist_config::AssistConfig, Assist, AssistId, AssistKind, GroupLabel};
+use crate::{
+    assist_config::AssistConfig, Assist, AssistId, AssistKind, AssistResolveStrategy, GroupLabel,
+};
 
 /// `AssistContext` allows to apply an assist or check if it could be applied.
 ///
@@ -105,14 +107,14 @@ impl<'a> AssistContext<'a> {
 }
 
 pub(crate) struct Assists {
-    resolve: bool,
     file: FileId,
+    resolve: AssistResolveStrategy,
     buf: Vec<Assist>,
     allowed: Option<Vec<AssistKind>>,
 }
 
 impl Assists {
-    pub(crate) fn new(ctx: &AssistContext, resolve: bool) -> Assists {
+    pub(crate) fn new(ctx: &AssistContext, resolve: AssistResolveStrategy) -> Assists {
         Assists {
             resolve,
             file: ctx.frange.file_id,
@@ -158,7 +160,7 @@ impl Assists {
     }
 
     fn add_impl(&mut self, mut assist: Assist, f: impl FnOnce(&mut AssistBuilder)) -> Option<()> {
-        let source_change = if self.resolve {
+        let source_change = if self.resolve.should_resolve(&assist.id) {
             let mut builder = AssistBuilder::new(self.file);
             f(&mut builder);
             Some(builder.finish())
diff --git a/crates/ide_assists/src/lib.rs b/crates/ide_assists/src/lib.rs
index 88ae5c9a9..2e0c58504 100644
--- a/crates/ide_assists/src/lib.rs
+++ b/crates/ide_assists/src/lib.rs
@@ -17,6 +17,8 @@ mod tests;
 pub mod utils;
 pub mod ast_transform;
 
+use std::str::FromStr;
+
 use hir::Semantics;
 use ide_db::base_db::FileRange;
 use ide_db::{label::Label, source_change::SourceChange, RootDatabase};
@@ -56,6 +58,35 @@ impl AssistKind {
             _ => return false,
         }
     }
+
+    pub fn name(&self) -> &str {
+        match self {
+            AssistKind::None => "None",
+            AssistKind::QuickFix => "QuickFix",
+            AssistKind::Generate => "Generate",
+            AssistKind::Refactor => "Refactor",
+            AssistKind::RefactorExtract => "RefactorExtract",
+            AssistKind::RefactorInline => "RefactorInline",
+            AssistKind::RefactorRewrite => "RefactorRewrite",
+        }
+    }
+}
+
+impl FromStr for AssistKind {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "None" => Ok(AssistKind::None),
+            "QuickFix" => Ok(AssistKind::QuickFix),
+            "Generate" => Ok(AssistKind::Generate),
+            "Refactor" => Ok(AssistKind::Refactor),
+            "RefactorExtract" => Ok(AssistKind::RefactorExtract),
+            "RefactorInline" => Ok(AssistKind::RefactorInline),
+            "RefactorRewrite" => Ok(AssistKind::RefactorRewrite),
+            unknown => Err(format!("Unknown AssistKind: '{}'", unknown)),
+        }
+    }
 }
 
 /// Unique identifier of the assist, should not be shown to the user
@@ -63,6 +94,41 @@ impl AssistKind {
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct AssistId(pub &'static str, pub AssistKind);
 
+/// A way to control how many asssist to resolve during the assist resolution.
+/// When an assist is resolved, its edits are calculated that might be costly to always do by default.
+#[derive(Debug)]
+pub enum AssistResolveStrategy {
+    /// No assists should be resolved.
+    None,
+    /// All assists should be resolved.
+    All,
+    /// Only a certain assist should be resolved.
+    Single(SingleResolve),
+}
+
+/// Hold the [`AssistId`] data of a certain assist to resolve.
+/// The original id object cannot be used due to a `'static` lifetime
+/// and the requirement to construct this struct dynamically during the resolve handling.
+#[derive(Debug)]
+pub struct SingleResolve {
+    /// The id of the assist.
+    pub assist_id: String,
+    // The kind of the assist.
+    pub assist_kind: AssistKind,
+}
+
+impl AssistResolveStrategy {
+    pub fn should_resolve(&self, id: &AssistId) -> bool {
+        match self {
+            AssistResolveStrategy::None => false,
+            AssistResolveStrategy::All => true,
+            AssistResolveStrategy::Single(single_resolve) => {
+                single_resolve.assist_id == id.0 && single_resolve.assist_kind == id.1
+            }
+        }
+    }
+}
+
 #[derive(Clone, Debug)]
 pub struct GroupLabel(pub String);
 
@@ -91,7 +157,7 @@ impl Assist {
     pub fn get(
         db: &RootDatabase,
         config: &AssistConfig,
-        resolve: bool,
+        resolve: AssistResolveStrategy,
         range: FileRange,
     ) -> Vec<Assist> {
         let sema = Semantics::new(db);
diff --git a/crates/ide_assists/src/tests.rs b/crates/ide_assists/src/tests.rs
index 6f4f97361..9c2847998 100644
--- a/crates/ide_assists/src/tests.rs
+++ b/crates/ide_assists/src/tests.rs
@@ -12,7 +12,10 @@ use stdx::{format_to, trim_indent};
 use syntax::TextRange;
 use test_utils::{assert_eq_text, extract_offset};
 
-use crate::{handlers::Handler, Assist, AssistConfig, AssistContext, AssistKind, Assists};
+use crate::{
+    handlers::Handler, Assist, AssistConfig, AssistContext, AssistKind, AssistResolveStrategy,
+    Assists, SingleResolve,
+};
 
 pub(crate) const TEST_CONFIG: AssistConfig = AssistConfig {
     snippet_cap: SnippetCap::new(true),
@@ -65,14 +68,14 @@ fn check_doc_test(assist_id: &str, before: &str, after: &str) {
     let before = db.file_text(file_id).to_string();
     let frange = FileRange { file_id, range: selection.into() };
 
-    let assist = Assist::get(&db, &TEST_CONFIG, true, frange)
+    let assist = Assist::get(&db, &TEST_CONFIG, AssistResolveStrategy::All, frange)
         .into_iter()
         .find(|assist| assist.id.0 == assist_id)
         .unwrap_or_else(|| {
             panic!(
                 "\n\nAssist is not applicable: {}\nAvailable assists: {}",
                 assist_id,
-                Assist::get(&db, &TEST_CONFIG, false, frange)
+                Assist::get(&db, &TEST_CONFIG, AssistResolveStrategy::None, frange)
                     .into_iter()
                     .map(|assist| assist.id.0)
                     .collect::<Vec<_>>()
@@ -108,7 +111,7 @@ fn check(handler: Handler, before: &str, expected: ExpectedResult, assist_label:
     let sema = Semantics::new(&db);
     let config = TEST_CONFIG;
     let ctx = AssistContext::new(sema, &config, frange);
-    let mut acc = Assists::new(&ctx, true);
+    let mut acc = Assists::new(&ctx, AssistResolveStrategy::All);
     handler(&mut acc, &ctx);
     let mut res = acc.finish();
 
@@ -186,7 +189,7 @@ fn assist_order_field_struct() {
     let (before_cursor_pos, before) = extract_offset(before);
     let (db, file_id) = with_single_file(&before);
     let frange = FileRange { file_id, range: TextRange::empty(before_cursor_pos) };
-    let assists = Assist::get(&db, &TEST_CONFIG, false, frange);
+    let assists = Assist::get(&db, &TEST_CONFIG, AssistResolveStrategy::None, frange);
     let mut assists = assists.iter();
 
     assert_eq!(assists.next().expect("expected assist").label, "Change visibility to pub(crate)");
@@ -211,7 +214,7 @@ pub fn test_some_range(a: int) -> bool {
 "#,
     );
 
-    let assists = Assist::get(&db, &TEST_CONFIG, false, frange);
+    let assists = Assist::get(&db, &TEST_CONFIG, AssistResolveStrategy::None, frange);
     let expected = labels(&assists);
 
     expect![[r#"
@@ -240,7 +243,7 @@ pub fn test_some_range(a: int) -> bool {
         let mut cfg = TEST_CONFIG;
         cfg.allowed = Some(vec![AssistKind::Refactor]);
 
-        let assists = Assist::get(&db, &cfg, false, frange);
+        let assists = Assist::get(&db, &cfg, AssistResolveStrategy::None, frange);
         let expected = labels(&assists);
 
         expect![[r#"
@@ -255,7 +258,7 @@ pub fn test_some_range(a: int) -> bool {
     {
         let mut cfg = TEST_CONFIG;
         cfg.allowed = Some(vec![AssistKind::RefactorExtract]);
-        let assists = Assist::get(&db, &cfg, false, frange);
+        let assists = Assist::get(&db, &cfg, AssistResolveStrategy::None, frange);
         let expected = labels(&assists);
 
         expect![[r#"
@@ -268,9 +271,250 @@ pub fn test_some_range(a: int) -> bool {
     {
         let mut cfg = TEST_CONFIG;
         cfg.allowed = Some(vec![AssistKind::QuickFix]);
-        let assists = Assist::get(&db, &cfg, false, frange);
+        let assists = Assist::get(&db, &cfg, AssistResolveStrategy::None, frange);
         let expected = labels(&assists);
 
         expect![[r#""#]].assert_eq(&expected);
     }
 }
+
+#[test]
+fn various_resolve_strategies() {
+    let (db, frange) = RootDatabase::with_range(
+        r#"
+pub fn test_some_range(a: int) -> bool {
+    if let 2..6 = $05$0 {
+        true
+    } else {
+        false
+    }
+}
+"#,
+    );
+
+    let mut cfg = TEST_CONFIG;
+    cfg.allowed = Some(vec![AssistKind::RefactorExtract]);
+
+    {
+        let assists = Assist::get(&db, &cfg, AssistResolveStrategy::None, frange);
+        assert_eq!(2, assists.len());
+        let mut assists = assists.into_iter();
+
+        let extract_into_variable_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "extract_variable",
+                    RefactorExtract,
+                ),
+                label: "Extract into variable",
+                group: None,
+                target: 59..60,
+                source_change: None,
+            }
+        "#]]
+        .assert_debug_eq(&extract_into_variable_assist);
+
+        let extract_into_function_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "extract_function",
+                    RefactorExtract,
+                ),
+                label: "Extract into function",
+                group: None,
+                target: 59..60,
+                source_change: None,
+            }
+        "#]]
+        .assert_debug_eq(&extract_into_function_assist);
+    }
+
+    {
+        let assists = Assist::get(
+            &db,
+            &cfg,
+            AssistResolveStrategy::Single(SingleResolve {
+                assist_id: "SOMETHING_MISMATCHING".to_string(),
+                assist_kind: AssistKind::RefactorExtract,
+            }),
+            frange,
+        );
+        assert_eq!(2, assists.len());
+        let mut assists = assists.into_iter();
+
+        let extract_into_variable_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "extract_variable",
+                    RefactorExtract,
+                ),
+                label: "Extract into variable",
+                group: None,
+                target: 59..60,
+                source_change: None,
+            }
+        "#]]
+        .assert_debug_eq(&extract_into_variable_assist);
+
+        let extract_into_function_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "extract_function",
+                    RefactorExtract,
+                ),
+                label: "Extract into function",
+                group: None,
+                target: 59..60,
+                source_change: None,
+            }
+        "#]]
+        .assert_debug_eq(&extract_into_function_assist);
+    }
+
+    {
+        let assists = Assist::get(
+            &db,
+            &cfg,
+            AssistResolveStrategy::Single(SingleResolve {
+                assist_id: "extract_variable".to_string(),
+                assist_kind: AssistKind::RefactorExtract,
+            }),
+            frange,
+        );
+        assert_eq!(2, assists.len());
+        let mut assists = assists.into_iter();
+
+        let extract_into_variable_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "extract_variable",
+                    RefactorExtract,
+                ),
+                label: "Extract into variable",
+                group: None,
+                target: 59..60,
+                source_change: Some(
+                    SourceChange {
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "let $0var_name = 5;\n    ",
+                                        delete: 45..45,
+                                    },
+                                    Indel {
+                                        insert: "var_name",
+                                        delete: 59..60,
+                                    },
+                                ],
+                            },
+                        },
+                        file_system_edits: [],
+                        is_snippet: true,
+                    },
+                ),
+            }
+        "#]]
+        .assert_debug_eq(&extract_into_variable_assist);
+
+        let extract_into_function_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "extract_function",
+                    RefactorExtract,
+                ),
+                label: "Extract into function",
+                group: None,
+                target: 59..60,
+                source_change: None,
+            }
+        "#]]
+        .assert_debug_eq(&extract_into_function_assist);
+    }
+
+    {
+        let assists = Assist::get(&db, &cfg, AssistResolveStrategy::All, frange);
+        assert_eq!(2, assists.len());
+        let mut assists = assists.into_iter();
+
+        let extract_into_variable_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "extract_variable",
+                    RefactorExtract,
+                ),
+                label: "Extract into variable",
+                group: None,
+                target: 59..60,
+                source_change: Some(
+                    SourceChange {
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "let $0var_name = 5;\n    ",
+                                        delete: 45..45,
+                                    },
+                                    Indel {
+                                        insert: "var_name",
+                                        delete: 59..60,
+                                    },
+                                ],
+                            },
+                        },
+                        file_system_edits: [],
+                        is_snippet: true,
+                    },
+                ),
+            }
+        "#]]
+        .assert_debug_eq(&extract_into_variable_assist);
+
+        let extract_into_function_assist = assists.next().unwrap();
+        expect![[r#"
+            Assist {
+                id: AssistId(
+                    "extract_function",
+                    RefactorExtract,
+                ),
+                label: "Extract into function",
+                group: None,
+                target: 59..60,
+                source_change: Some(
+                    SourceChange {
+                        source_file_edits: {
+                            FileId(
+                                0,
+                            ): TextEdit {
+                                indels: [
+                                    Indel {
+                                        insert: "fun_name()",
+                                        delete: 59..60,
+                                    },
+                                    Indel {
+                                        insert: "\n\nfn $0fun_name() -> i32 {\n    5\n}",
+                                        delete: 110..110,
+                                    },
+                                ],
+                            },
+                        },
+                        file_system_edits: [],
+                        is_snippet: true,
+                    },
+                ),
+            }
+        "#]]
+        .assert_debug_eq(&extract_into_function_assist);
+    }
+}
diff --git a/crates/rust-analyzer/src/cli/diagnostics.rs b/crates/rust-analyzer/src/cli/diagnostics.rs
index 74f784338..c33c8179c 100644
--- a/crates/rust-analyzer/src/cli/diagnostics.rs
+++ b/crates/rust-analyzer/src/cli/diagnostics.rs
@@ -7,7 +7,7 @@ use anyhow::anyhow;
 use rustc_hash::FxHashSet;
 
 use hir::{db::HirDatabase, Crate, Module};
-use ide::{DiagnosticsConfig, Severity};
+use ide::{AssistResolveStrategy, DiagnosticsConfig, Severity};
 use ide_db::base_db::SourceDatabaseExt;
 
 use crate::cli::{
@@ -57,8 +57,9 @@ pub fn diagnostics(
             let crate_name =
                 module.krate().display_name(db).as_deref().unwrap_or("unknown").to_string();
             println!("processing crate: {}, module: {}", crate_name, _vfs.file_path(file_id));
-            for diagnostic in
-                analysis.diagnostics(&DiagnosticsConfig::default(), false, file_id).unwrap()
+            for diagnostic in analysis
+                .diagnostics(&DiagnosticsConfig::default(), AssistResolveStrategy::None, file_id)
+                .unwrap()
             {
                 if matches!(diagnostic.severity, Severity::Error) {
                     found_error = true;
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 1f59402e5..f6e40f872 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -8,8 +8,9 @@ use std::{
 };
 
 use ide::{
-    AnnotationConfig, FileId, FilePosition, FileRange, HoverAction, HoverGotoTypeData, Query,
-    RangeInfo, Runnable, RunnableKind, SearchScope, SourceChange, TextEdit,
+    AnnotationConfig, AssistKind, AssistResolveStrategy, FileId, FilePosition, FileRange,
+    HoverAction, HoverGotoTypeData, Query, RangeInfo, Runnable, RunnableKind, SearchScope,
+    SingleResolve, SourceChange, TextEdit,
 };
 use ide_db::SymbolKind;
 use itertools::Itertools;
@@ -27,7 +28,7 @@ use lsp_types::{
 use project_model::TargetKind;
 use serde::{Deserialize, Serialize};
 use serde_json::to_value;
-use stdx::{format_to, split_once};
+use stdx::format_to;
 use syntax::{algo, ast, AstNode, TextRange, TextSize};
 
 use crate::{
@@ -1004,10 +1005,15 @@ pub(crate) fn handle_code_action(
     let mut res: Vec<lsp_ext::CodeAction> = Vec::new();
 
     let code_action_resolve_cap = snap.config.code_action_resolve();
+    let resolve = if code_action_resolve_cap {
+        AssistResolveStrategy::None
+    } else {
+        AssistResolveStrategy::All
+    };
     let assists = snap.analysis.assists_with_fixes(
         &assists_config,
         &snap.config.diagnostics(),
-        !code_action_resolve_cap,
+        resolve,
         frange,
     )?;
     for (index, assist) in assists.into_iter().enumerate() {
@@ -1052,22 +1058,68 @@ pub(crate) fn handle_code_action_resolve(
         .only
         .map(|it| it.into_iter().filter_map(from_proto::assist_kind).collect());
 
+    let (assist_index, assist_resolve) = match parse_action_id(&params.id) {
+        Ok(parsed_data) => parsed_data,
+        Err(e) => {
+            return Err(LspError::new(
+                ErrorCode::InvalidParams as i32,
+                format!("Failed to parse action id string '{}': {}", params.id, e),
+            )
+            .into())
+        }
+    };
+
+    let expected_assist_id = assist_resolve.assist_id.clone();
+    let expected_kind = assist_resolve.assist_kind;
+
     let assists = snap.analysis.assists_with_fixes(
         &assists_config,
         &snap.config.diagnostics(),
-        true,
+        AssistResolveStrategy::Single(assist_resolve),
         frange,
     )?;
 
-    let (id, index) = split_once(&params.id, ':').unwrap();
-    let index = index.parse::<usize>().unwrap();
-    let assist = &assists[index];
-    assert!(assist.id.0 == id);
+    let assist = match assists.get(assist_index) {
+        Some(assist) => assist,
+        None => return Err(LspError::new(
+            ErrorCode::InvalidParams as i32,
+            format!(
+                "Failed to find the assist for index {} provided by the resolve request. Resolve request assist id: {}",
+                assist_index, params.id,
+            ),
+        )
+        .into())
+    };
+    if assist.id.0 != expected_assist_id || assist.id.1 != expected_kind {
+        return Err(LspError::new(
+            ErrorCode::InvalidParams as i32,
+            format!(
+                "Mismatching assist at index {} for the resolve parameters given. Resolve request assist id: {}, actual id: {:?}.",
+                assist_index, params.id, assist.id
+            ),
+        )
+        .into());
+    }
     let edit = to_proto::code_action(&snap, assist.clone(), None)?.edit;
     code_action.edit = edit;
     Ok(code_action)
 }
 
+fn parse_action_id(action_id: &str) -> Result<(usize, SingleResolve), String> {
+    let id_parts = action_id.split(':').collect_vec();
+    match id_parts.as_slice() {
+        &[assist_id_string, assist_kind_string, index_string] => {
+            let assist_kind: AssistKind = assist_kind_string.parse()?;
+            let index: usize = match index_string.parse() {
+                Ok(index) => index,
+                Err(e) => return Err(format!("Incorrect index string: {}", e)),
+            };
+            Ok((index, SingleResolve { assist_id: assist_id_string.to_string(), assist_kind }))
+        }
+        _ => Err("Action id contains incorrect number of segments".to_string()),
+    }
+}
+
 pub(crate) fn handle_code_lens(
     snap: GlobalStateSnapshot,
     params: lsp_types::CodeLensParams,
@@ -1182,7 +1234,7 @@ pub(crate) fn publish_diagnostics(
 
     let diagnostics: Vec<Diagnostic> = snap
         .analysis
-        .diagnostics(&snap.config.diagnostics(), false, file_id)?
+        .diagnostics(&snap.config.diagnostics(), AssistResolveStrategy::None, file_id)?
         .into_iter()
         .map(|d| Diagnostic {
             range: to_proto::range(&line_index, d.range),
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index c2361b32e..1d27aa7b3 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -897,7 +897,7 @@ pub(crate) fn code_action(
         (Some(it), _) => res.edit = Some(snippet_workspace_edit(snap, it)?),
         (None, Some((index, code_action_params))) => {
             res.data = Some(lsp_ext::CodeActionData {
-                id: format!("{}:{}", assist.id.0, index.to_string()),
+                id: format!("{}:{}:{}", assist.id.0, assist.id.1.name(), index),
                 code_action_params,
             });
         }