3 files changed, 446 insertions, 18 deletions

diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index d1a250d48..a8b169e87 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -87,7 +87,7 @@ pub use crate::{
 pub use hir::{Documentation, Semantics};
 pub use ide_assists::{Assist, AssistConfig, AssistId, AssistKind};
 pub use ide_completion::{
-    CompletionConfig, CompletionItem, CompletionItemKind, CompletionScore, ImportEdit,
+    CompletionConfig, CompletionItem, CompletionItemKind, CompletionRelevance, ImportEdit,
     InsertTextFormat,
 };
 pub use ide_db::{
@@ -447,6 +447,15 @@ impl Analysis {
         self.with_db(|db| runnables::runnables(db, file_id))
     }
 
+    /// Returns the set of tests for the given file position.
+    pub fn related_tests(
+        &self,
+        position: FilePosition,
+        search_scope: Option<SearchScope>,
+    ) -> Cancelable<Vec<Runnable>> {
+        self.with_db(|db| runnables::related_tests(db, position, search_scope))
+    }
+
     /// Computes syntax highlighting for the given file
     pub fn highlight(&self, file_id: FileId) -> Cancelable<Vec<HlRange>> {
         self.with_db(|db| syntax_highlighting::highlight(db, file_id, None, false))
diff --git a/crates/ide/src/references/rename.rs b/crates/ide/src/references/rename.rs
index bb68bcc78..1e378279d 100644
--- a/crates/ide/src/references/rename.rs
+++ b/crates/ide/src/references/rename.rs
@@ -21,7 +21,7 @@ use crate::{display::TryToNav, FilePosition, FileSystemEdit, RangeInfo, SourceCh
 
 type RenameResult<T> = Result<T, RenameError>;
 #[derive(Debug)]
-pub struct RenameError(pub(crate) String);
+pub struct RenameError(String);
 
 impl fmt::Display for RenameError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -47,16 +47,15 @@ pub(crate) fn prepare_rename(
     let sema = Semantics::new(db);
     let source_file = sema.parse(position.file_id);
     let syntax = source_file.syntax();
-    let range = match &sema
+    let name_like = sema
         .find_node_at_offset_with_descend(&syntax, position.offset)
-        .ok_or_else(|| format_err!("No references found at position"))?
-    {
+        .ok_or_else(|| format_err!("No references found at position"))?;
+    let node = match &name_like {
         ast::NameLike::Name(it) => it.syntax(),
         ast::NameLike::NameRef(it) => it.syntax(),
         ast::NameLike::Lifetime(it) => it.syntax(),
-    }
-    .text_range();
-    Ok(RangeInfo::new(range, ()))
+    };
+    Ok(RangeInfo::new(sema.original_range(node).range, ()))
 }
 
 // Feature: Rename
@@ -546,6 +545,8 @@ mod tests {
 
     use crate::{fixture, FileId};
 
+    use super::{RangeInfo, RenameError};
+
     fn check(new_name: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
         let ra_fixture_after = &trim_indent(ra_fixture_after);
         let (analysis, position) = fixture::position(ra_fixture_before);
@@ -591,6 +592,45 @@ mod tests {
         expect.assert_debug_eq(&source_change)
     }
 
+    fn check_prepare(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = fixture::position(ra_fixture);
+        let result = analysis
+            .prepare_rename(position)
+            .unwrap_or_else(|err| panic!("PrepareRename was cancelled: {}", err));
+        match result {
+            Ok(RangeInfo { range, info: () }) => {
+                let source = analysis.file_text(position.file_id).unwrap();
+                expect.assert_eq(&format!("{:?}: {}", range, &source[range]))
+            }
+            Err(RenameError(err)) => expect.assert_eq(&err),
+        };
+    }
+
+    #[test]
+    fn test_prepare_rename_namelikes() {
+        check_prepare(r"fn name$0<'lifetime>() {}", expect![[r#"3..7: name"#]]);
+        check_prepare(r"fn name<'lifetime$0>() {}", expect![[r#"8..17: 'lifetime"#]]);
+        check_prepare(r"fn name<'lifetime>() { name$0(); }", expect![[r#"23..27: name"#]]);
+    }
+
+    #[test]
+    fn test_prepare_rename_in_macro() {
+        check_prepare(
+            r"macro_rules! foo {
+    ($ident:ident) => {
+        pub struct $ident;
+    }
+}
+foo!(Foo$0);",
+            expect![[r#"83..86: Foo"#]],
+        );
+    }
+
+    #[test]
+    fn test_prepare_rename_keyword() {
+        check_prepare(r"struct$0 Foo;", expect![[r#"No references found at position"#]]);
+    }
+
     #[test]
     fn test_rename_to_underscore() {
         check("_", r#"fn main() { let i$0 = 1; }"#, r#"fn main() { let _ = 1; }"#);
diff --git a/crates/ide/src/runnables.rs b/crates/ide/src/runnables.rs
index 280565563..27d35de5b 100644
--- a/crates/ide/src/runnables.rs
+++ b/crates/ide/src/runnables.rs
@@ -1,10 +1,17 @@
 use std::fmt;
 
+use ast::NameOwner;
 use cfg::CfgExpr;
-use hir::{AsAssocItem, HasAttrs, HasSource, Semantics};
+use hir::{AsAssocItem, HasAttrs, HasSource, HirDisplay, Semantics};
 use ide_assists::utils::test_related_attribute;
-use ide_db::{defs::Definition, RootDatabase, SymbolKind};
+use ide_db::{
+    base_db::{FilePosition, FileRange},
+    defs::Definition,
+    search::SearchScope,
+    RootDatabase, SymbolKind,
+};
 use itertools::Itertools;
+use rustc_hash::FxHashSet;
 use syntax::{
     ast::{self, AstNode, AttrsOwner},
     match_ast, SyntaxNode,
@@ -12,17 +19,17 @@ use syntax::{
 
 use crate::{
     display::{ToNav, TryToNav},
-    FileId, NavigationTarget,
+    references, FileId, NavigationTarget,
 };
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub struct Runnable {
     pub nav: NavigationTarget,
     pub kind: RunnableKind,
     pub cfg: Option<CfgExpr>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub enum TestId {
     Name(String),
     Path(String),
@@ -37,7 +44,7 @@ impl fmt::Display for TestId {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq)]
 pub enum RunnableKind {
     Test { test_id: TestId, attr: TestAttr },
     TestMod { path: String },
@@ -105,6 +112,105 @@ pub(crate) fn runnables(db: &RootDatabase, file_id: FileId) -> Vec<Runnable> {
     res
 }
 
+// Feature: Related Tests
+//
+// Provides a sneak peek of all tests where the current item is used.
+//
+// The simplest way to use this feature is via the context menu:
+//  - Right-click on the selected item. The context menu opens.
+//  - Select **Peek related tests**
+//
+// |===
+// | Editor  | Action Name
+//
+// | VS Code | **Rust Analyzer: Peek related tests**
+// |===
+pub(crate) fn related_tests(
+    db: &RootDatabase,
+    position: FilePosition,
+    search_scope: Option<SearchScope>,
+) -> Vec<Runnable> {
+    let sema = Semantics::new(db);
+    let mut res: FxHashSet<Runnable> = FxHashSet::default();
+
+    find_related_tests(&sema, position, search_scope, &mut res);
+
+    res.into_iter().collect_vec()
+}
+
+fn find_related_tests(
+    sema: &Semantics<RootDatabase>,
+    position: FilePosition,
+    search_scope: Option<SearchScope>,
+    tests: &mut FxHashSet<Runnable>,
+) {
+    if let Some(refs) = references::find_all_refs(&sema, position, search_scope) {
+        for (file_id, refs) in refs.references {
+            let file = sema.parse(file_id);
+            let file = file.syntax();
+            let functions = refs.iter().filter_map(|(range, _)| {
+                let token = file.token_at_offset(range.start()).next()?;
+                let token = sema.descend_into_macros(token);
+                let syntax = token.parent();
+                syntax.ancestors().find_map(ast::Fn::cast)
+            });
+
+            for fn_def in functions {
+                if let Some(runnable) = as_test_runnable(&sema, &fn_def) {
+                    // direct test
+                    tests.insert(runnable);
+                } else if let Some(module) = parent_test_module(&sema, &fn_def) {
+                    // indirect test
+                    find_related_tests_in_module(sema, &fn_def, &module, tests);
+                }
+            }
+        }
+    }
+}
+
+fn find_related_tests_in_module(
+    sema: &Semantics<RootDatabase>,
+    fn_def: &ast::Fn,
+    parent_module: &hir::Module,
+    tests: &mut FxHashSet<Runnable>,
+) {
+    if let Some(fn_name) = fn_def.name() {
+        let mod_source = parent_module.definition_source(sema.db);
+        let range = match mod_source.value {
+            hir::ModuleSource::Module(m) => m.syntax().text_range(),
+            hir::ModuleSource::BlockExpr(b) => b.syntax().text_range(),
+            hir::ModuleSource::SourceFile(f) => f.syntax().text_range(),
+        };
+
+        let file_id = mod_source.file_id.original_file(sema.db);
+        let mod_scope = SearchScope::file_range(FileRange { file_id, range });
+        let fn_pos = FilePosition { file_id, offset: fn_name.syntax().text_range().start() };
+        find_related_tests(sema, fn_pos, Some(mod_scope), tests)
+    }
+}
+
+fn as_test_runnable(sema: &Semantics<RootDatabase>, fn_def: &ast::Fn) -> Option<Runnable> {
+    if test_related_attribute(&fn_def).is_some() {
+        let function = sema.to_def(fn_def)?;
+        runnable_fn(sema, function)
+    } else {
+        None
+    }
+}
+
+fn parent_test_module(sema: &Semantics<RootDatabase>, fn_def: &ast::Fn) -> Option<hir::Module> {
+    fn_def.syntax().ancestors().find_map(|node| {
+        let module = ast::Module::cast(node)?;
+        let module = sema.to_def(&module)?;
+
+        if has_test_function_or_multiple_test_submodules(sema, &module) {
+            Some(module)
+        } else {
+            None
+        }
+    })
+}
+
 fn runnables_mod(sema: &Semantics<RootDatabase>, acc: &mut Vec<Runnable>, module: hir::Module) {
     acc.extend(module.declarations(sema.db).into_iter().filter_map(|def| {
         let runnable = match def {
@@ -234,11 +340,21 @@ fn module_def_doctest(sema: &Semantics<RootDatabase>, def: hir::ModuleDef) -> Op
             // FIXME: this also looks very wrong
             if let Some(assoc_def) = assoc_def {
                 if let hir::AssocItemContainer::Impl(imp) = assoc_def.container(sema.db) {
-                    if let Some(adt) = imp.target_ty(sema.db).as_adt() {
-                        let name = adt.name(sema.db).to_string();
+                    let ty = imp.target_ty(sema.db);
+                    if let Some(adt) = ty.as_adt() {
+                        let name = adt.name(sema.db);
                         let idx = path.rfind(':').map_or(0, |idx| idx + 1);
                         let (prefix, suffix) = path.split_at(idx);
-                        return format!("{}{}::{}", prefix, name, suffix);
+                        let mut ty_params = ty.type_parameters().peekable();
+                        let params = if ty_params.peek().is_some() {
+                            format!(
+                                "<{}>",
+                                ty_params.format_with(", ", |ty, cb| cb(&ty.display(sema.db)))
+                            )
+                        } else {
+                            String::new()
+                        };
+                        return format!("{}{}{}::{}", prefix, name, params, suffix);
                     }
                 }
             }
@@ -256,7 +372,7 @@ fn module_def_doctest(sema: &Semantics<RootDatabase>, def: hir::ModuleDef) -> Op
     Some(res)
 }
 
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
 pub struct TestAttr {
     pub ignore: bool,
 }
@@ -349,6 +465,12 @@ mod tests {
         );
     }
 
+    fn check_tests(ra_fixture: &str, expect: Expect) {
+        let (analysis, position) = fixture::position(ra_fixture);
+        let tests = analysis.related_tests(position, None).unwrap();
+        expect.assert_debug_eq(&tests);
+    }
+
     #[test]
     fn test_runnables() {
         check(
@@ -1074,4 +1196,261 @@ mod tests {
             "#]],
         );
     }
+
+    #[test]
+    fn find_no_tests() {
+        check_tests(
+            r#"
+//- /lib.rs
+fn foo$0() {  };
+"#,
+            expect![[r#"
+                []
+            "#]],
+        );
+    }
+
+    #[test]
+    fn find_direct_fn_test() {
+        check_tests(
+            r#"
+//- /lib.rs
+fn foo$0() { };
+
+mod tests {
+    #[test]
+    fn foo_test() {
+        super::foo()
+    }
+}
+"#,
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                0,
+                            ),
+                            full_range: 31..85,
+                            focus_range: 46..54,
+                            name: "foo_test",
+                            kind: Function,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "tests::foo_test",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg: None,
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn find_direct_struct_test() {
+        check_tests(
+            r#"
+//- /lib.rs
+struct Fo$0o;
+fn foo(arg: &Foo) { };
+
+mod tests {
+    use super::*;
+
+    #[test]
+    fn foo_test() {
+        foo(Foo);
+    }
+}
+"#,
+            expect![[r#"
+            [
+                Runnable {
+                    nav: NavigationTarget {
+                        file_id: FileId(
+                            0,
+                        ),
+                        full_range: 71..122,
+                        focus_range: 86..94,
+                        name: "foo_test",
+                        kind: Function,
+                    },
+                    kind: Test {
+                        test_id: Path(
+                            "tests::foo_test",
+                        ),
+                        attr: TestAttr {
+                            ignore: false,
+                        },
+                    },
+                    cfg: None,
+                },
+            ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn find_indirect_fn_test() {
+        check_tests(
+            r#"
+//- /lib.rs
+fn foo$0() { };
+
+mod tests {
+    use super::foo;
+
+    fn check1() {
+        check2()
+    }
+
+    fn check2() {
+        foo()
+    }
+
+    #[test]
+    fn foo_test() {
+        check1()
+    }
+}
+"#,
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                0,
+                            ),
+                            full_range: 133..183,
+                            focus_range: 148..156,
+                            name: "foo_test",
+                            kind: Function,
+                        },
+                        kind: Test {
+                            test_id: Path(
+                                "tests::foo_test",
+                            ),
+                            attr: TestAttr {
+                                ignore: false,
+                            },
+                        },
+                        cfg: None,
+                    },
+                ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn tests_are_unique() {
+        check_tests(
+            r#"
+//- /lib.rs
+fn foo$0() { };
+
+mod tests {
+    use super::foo;
+
+    #[test]
+    fn foo_test() {
+        foo();
+        foo();
+    }
+
+    #[test]
+    fn foo2_test() {
+        foo();
+        foo();
+    }
+
+}
+"#,
+            expect![[r#"
+            [
+                Runnable {
+                    nav: NavigationTarget {
+                        file_id: FileId(
+                            0,
+                        ),
+                        full_range: 52..115,
+                        focus_range: 67..75,
+                        name: "foo_test",
+                        kind: Function,
+                    },
+                    kind: Test {
+                        test_id: Path(
+                            "tests::foo_test",
+                        ),
+                        attr: TestAttr {
+                            ignore: false,
+                        },
+                    },
+                    cfg: None,
+                },
+                Runnable {
+                    nav: NavigationTarget {
+                        file_id: FileId(
+                            0,
+                        ),
+                        full_range: 121..185,
+                        focus_range: 136..145,
+                        name: "foo2_test",
+                        kind: Function,
+                    },
+                    kind: Test {
+                        test_id: Path(
+                            "tests::foo2_test",
+                        ),
+                        attr: TestAttr {
+                            ignore: false,
+                        },
+                    },
+                    cfg: None,
+                },
+            ]
+            "#]],
+        );
+    }
+
+    #[test]
+    fn doc_test_type_params() {
+        check(
+            r#"
+//- /lib.rs
+$0
+struct Foo<T, U>;
+
+impl<T, U> Foo<T, U> {
+    /// ```rust
+    /// ````
+    fn t() {}
+}
+"#,
+            &[&DOCTEST],
+            expect![[r#"
+                [
+                    Runnable {
+                        nav: NavigationTarget {
+                            file_id: FileId(
+                                0,
+                            ),
+                            full_range: 47..85,
+                            name: "t",
+                        },
+                        kind: DocTest {
+                            test_id: Path(
+                                "Foo<T, U>::t",
+                            ),
+                        },
+                        cfg: None,
+                    },
+                ]
+            "#]],
+        );
+    }
 }