Merge #7799

7799: Related tests r=matklad a=vsrs

![tests](https://user-images.githubusercontent.com/62505555/109397453-a9013680-7947-11eb-8b11-ac03079f7645.gif)
This adds an ability to look for tests for the item under the cursor: function, constant, data type, etc

The LSP part is bound to change. But the feature itself already works and I'm looking for a feedback :)



Co-authored-by: vsrs <[email protected]>

8 files changed, 391 insertions, 17 deletions

diff --git a/crates/cfg/src/cfg_expr.rs b/crates/cfg/src/cfg_expr.rs
index 42327f1e1..069fc01d0 100644
--- a/crates/cfg/src/cfg_expr.rs
+++ b/crates/cfg/src/cfg_expr.rs
@@ -49,7 +49,7 @@ impl fmt::Display for CfgAtom {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub enum CfgExpr {
     Invalid,
     Atom(CfgAtom),
diff --git a/crates/ide/src/lib.rs b/crates/ide/src/lib.rs
index 0a493d2f3..a8b169e87 100644
--- a/crates/ide/src/lib.rs
+++ b/crates/ide/src/lib.rs
@@ -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/runnables.rs b/crates/ide/src/runnables.rs
index 280565563..faa91541e 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 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 {
@@ -256,7 +362,7 @@ 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 +455,12 @@ 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 +1186,224 @@ 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,
+                },
+            ]
+            "#]],
+        );
+    }
 }
diff --git a/crates/ide_db/src/search.rs b/crates/ide_db/src/search.rs
index ddcfbd3f3..fa18703e1 100644
--- a/crates/ide_db/src/search.rs
+++ b/crates/ide_db/src/search.rs
@@ -86,6 +86,10 @@ impl SearchScope {
         SearchScope::new(std::iter::once((file, None)).collect())
     }
 
+    pub fn file_range(range: FileRange) -> SearchScope {
+        SearchScope::new(std::iter::once((range.file_id, Some(range.range))).collect())
+    }
+
     pub fn files(files: &[FileId]) -> SearchScope {
         SearchScope::new(files.iter().map(|f| (*f, None)).collect())
     }
diff --git a/crates/rust-analyzer/src/handlers.rs b/crates/rust-analyzer/src/handlers.rs
index 6cc433cb8..706a39dab 100644
--- a/crates/rust-analyzer/src/handlers.rs
+++ b/crates/rust-analyzer/src/handlers.rs
@@ -555,7 +555,7 @@ pub(crate) fn handle_runnables(
         if should_skip_target(&runnable, cargo_spec.as_ref()) {
             continue;
         }
-        let mut runnable = to_proto::runnable(&snap, file_id, runnable)?;
+        let mut runnable = to_proto::runnable(&snap, runnable)?;
         if expect_test {
             runnable.label = format!("{} + expect", runnable.label);
             runnable.args.expect_test = Some(true);
@@ -607,6 +607,24 @@ pub(crate) fn handle_runnables(
     Ok(res)
 }
 
+pub(crate) fn handle_related_tests(
+    snap: GlobalStateSnapshot,
+    params: lsp_types::TextDocumentPositionParams,
+) -> Result<Vec<lsp_ext::TestInfo>> {
+    let _p = profile::span("handle_related_tests");
+    let position = from_proto::file_position(&snap, params)?;
+
+    let tests = snap.analysis.related_tests(position, None)?;
+    let mut res = Vec::new();
+    for it in tests {
+        if let Ok(runnable) = to_proto::runnable(&snap, it) {
+            res.push(lsp_ext::TestInfo { runnable })
+        }
+    }
+
+    Ok(res)
+}
+
 pub(crate) fn handle_completion(
     snap: GlobalStateSnapshot,
     params: lsp_types::CompletionParams,
@@ -772,7 +790,7 @@ pub(crate) fn handle_hover(
             contents: HoverContents::Markup(to_proto::markup_content(info.info.markup)),
             range: Some(range),
         },
-        actions: prepare_hover_actions(&snap, position.file_id, &info.info.actions),
+        actions: prepare_hover_actions(&snap, &info.info.actions),
     };
 
     Ok(Some(hover))
@@ -1440,17 +1458,16 @@ fn show_impl_command_link(
 
 fn runnable_action_links(
     snap: &GlobalStateSnapshot,
-    file_id: FileId,
     runnable: Runnable,
 ) -> Option<lsp_ext::CommandLinkGroup> {
-    let cargo_spec = CargoTargetSpec::for_file(&snap, file_id).ok()?;
+    let cargo_spec = CargoTargetSpec::for_file(&snap, runnable.nav.file_id).ok()?;
     let hover_config = snap.config.hover();
     if !hover_config.runnable() || should_skip_target(&runnable, cargo_spec.as_ref()) {
         return None;
     }
 
     let action: &'static _ = runnable.action();
-    to_proto::runnable(snap, file_id, runnable).ok().map(|r| {
+    to_proto::runnable(snap, runnable).ok().map(|r| {
         let mut group = lsp_ext::CommandLinkGroup::default();
 
         if hover_config.run {
@@ -1489,7 +1506,6 @@ fn goto_type_action_links(
 
 fn prepare_hover_actions(
     snap: &GlobalStateSnapshot,
-    file_id: FileId,
     actions: &[HoverAction],
 ) -> Vec<lsp_ext::CommandLinkGroup> {
     if snap.config.hover().none() || !snap.config.hover_actions() {
@@ -1500,7 +1516,7 @@ fn prepare_hover_actions(
         .iter()
         .filter_map(|it| match it {
             HoverAction::Implementation(position) => show_impl_command_link(snap, position),
-            HoverAction::Runnable(r) => runnable_action_links(snap, file_id, r.clone()),
+            HoverAction::Runnable(r) => runnable_action_links(snap, r.clone()),
             HoverAction::GoToType(targets) => goto_type_action_links(snap, targets),
         })
         .collect()
diff --git a/crates/rust-analyzer/src/lsp_ext.rs b/crates/rust-analyzer/src/lsp_ext.rs
index 0d2c8f7ff..efcdcd1d9 100644
--- a/crates/rust-analyzer/src/lsp_ext.rs
+++ b/crates/rust-analyzer/src/lsp_ext.rs
@@ -177,6 +177,19 @@ pub struct CargoRunnable {
     pub expect_test: Option<bool>,
 }
 
+pub enum RelatedTests {}
+
+impl Request for RelatedTests {
+    type Params = lsp_types::TextDocumentPositionParams;
+    type Result = Vec<TestInfo>;
+    const METHOD: &'static str = "rust-analyzer/relatedTests";
+}
+
+#[derive(Debug, Deserialize, Serialize)]
+pub struct TestInfo {
+    pub runnable: Runnable,
+}
+
 pub enum InlayHints {}
 
 impl Request for InlayHints {
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index f0cb309e4..984790d35 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -500,6 +500,7 @@ impl GlobalState {
             .on::<lsp_ext::ExpandMacro>(handlers::handle_expand_macro)
             .on::<lsp_ext::ParentModule>(handlers::handle_parent_module)
             .on::<lsp_ext::Runnables>(handlers::handle_runnables)
+            .on::<lsp_ext::RelatedTests>(handlers::handle_related_tests)
             .on::<lsp_ext::InlayHints>(handlers::handle_inlay_hints)
             .on::<lsp_ext::CodeActionRequest>(handlers::handle_code_action)
             .on::<lsp_ext::CodeActionResolveRequest>(handlers::handle_code_action_resolve)
diff --git a/crates/rust-analyzer/src/to_proto.rs b/crates/rust-analyzer/src/to_proto.rs
index 1a8cdadad..9ca0915b9 100644
--- a/crates/rust-analyzer/src/to_proto.rs
+++ b/crates/rust-analyzer/src/to_proto.rs
@@ -838,11 +838,10 @@ pub(crate) fn resolved_code_action(
 
 pub(crate) fn runnable(
     snap: &GlobalStateSnapshot,
-    file_id: FileId,
     runnable: Runnable,
 ) -> Result<lsp_ext::Runnable> {
     let config = snap.config.runnables();
-    let spec = CargoTargetSpec::for_file(snap, file_id)?;
+    let spec = CargoTargetSpec::for_file(snap, runnable.nav.file_id)?;
     let workspace_root = spec.as_ref().map(|it| it.workspace_root.clone());
     let target = spec.as_ref().map(|s| s.target.clone());
     let (cargo_args, executable_args) =
@@ -875,7 +874,7 @@ pub(crate) fn code_lens(
             let annotation_range = range(&line_index, annotation.range);
 
             let action = run.action();
-            let r = runnable(&snap, run.nav.file_id, run)?;
+            let r = runnable(&snap, run)?;
 
             let command = if debug {
                 command::debug_single(&r)