Make modules with tests runnable

Fixes #154

crates/ra_analysis/src/imp.rs

@@ -181,6 +181,28 @@ impl AnalysisImpl {
         };
         Ok(query.search(&buf))
     }
+
+    pub(crate) fn module_path(&self, position: FilePosition) -> Cancelable<Option<String>> {
+        let descr = match source_binder::module_from_position(&*self.db, position)? {
+            None => return Ok(None),
+            Some(it) => it,
+        };
+        let name = match descr.name() {
+            None => return Ok(None),
+            Some(it) => it.to_string(),
+        };
+
+        let modules = descr.path_to_root();
+
+        let path = modules
+            .iter()
+            .filter_map(|s| s.name())
+            .skip(1) // name is already part of the string.
+            .fold(name, |path, it| format!("{}::{}", it, path));
+
+        Ok(Some(path.to_string()))
+    }
+
     /// This returns `Vec` because a module may be included from several places. We
     /// don't handle this case yet though, so the Vec has length at most one.
     pub fn parent_module(&self, position: FilePosition) -> Cancelable<Vec<(FileId, FileSymbol)>> {

crates/ra_analysis/src/lib.rs

@@ -15,6 +15,7 @@ mod imp;
 mod completion;
 mod symbol_index;
 pub mod mock_analysis;
+mod runnables;
 
 mod extend_selection;
 mod syntax_highlighting;
@@ -33,10 +34,12 @@ use crate::{
     symbol_index::SymbolIndex,
 };
 
-pub use crate::completion::{CompletionItem, CompletionItemKind, InsertText};
+pub use crate::{
+    completion::{CompletionItem, CompletionItemKind, InsertText},
+    runnables::{Runnable, RunnableKind}
+};
 pub use ra_editor::{
-    FileSymbol, Fold, FoldKind, HighlightedRange, LineIndex, Runnable, RunnableKind, StructureNode,
-    Severity
+    FileSymbol, Fold, FoldKind, HighlightedRange, LineIndex, StructureNode, Severity
 };
 pub use hir::FnSignatureInfo;
 
@@ -336,6 +339,9 @@ impl Analysis {
     pub fn parent_module(&self, position: FilePosition) -> Cancelable<Vec<(FileId, FileSymbol)>> {
         self.imp.parent_module(position)
     }
+    pub fn module_path(&self, position: FilePosition) -> Cancelable<Option<String>> {
+        self.imp.module_path(position)
+    }
     pub fn crate_for(&self, file_id: FileId) -> Cancelable<Vec<CrateId>> {
         self.imp.crate_for(file_id)
     }
@@ -344,7 +350,7 @@ impl Analysis {
     }
     pub fn runnables(&self, file_id: FileId) -> Cancelable<Vec<Runnable>> {
         let file = self.imp.file_syntax(file_id);
-        Ok(ra_editor::runnables(&file))
+        Ok(runnables::runnables(self, &file, file_id))
     }
     pub fn highlight(&self, file_id: FileId) -> Cancelable<Vec<HighlightedRange>> {
         syntax_highlighting::highlight(&*self.imp.db, file_id)

crates/ra_analysis/src/runnables.rs

@@ -0,0 +1,72 @@
+use ra_syntax::{
+    ast::{self, AstNode, NameOwner, ModuleItemOwner},
+    SourceFileNode, TextRange, SyntaxNodeRef,
+    TextUnit,
+};
+use crate::{
+    Analysis, FileId, FilePosition
+};
+
+#[derive(Debug)]
+pub struct Runnable {
+    pub range: TextRange,
+    pub kind: RunnableKind,
+}
+
+#[derive(Debug)]
+pub enum RunnableKind {
+    Test { name: String },
+    TestMod { path: String },
+    Bin,
+}
+
+pub fn runnables(
+    analysis: &Analysis,
+    file_node: &SourceFileNode,
+    file_id: FileId,
+) -> Vec<Runnable> {
+    file_node
+        .syntax()
+        .descendants()
+        .filter_map(|i| runnable(analysis, i, file_id))
+        .collect()
+}
+
+fn runnable<'a>(analysis: &Analysis, item: SyntaxNodeRef<'a>, file_id: FileId) -> Option<Runnable> {
+    if let Some(f) = ast::FnDef::cast(item) {
+        let name = f.name()?.text();
+        let kind = if name == "main" {
+            RunnableKind::Bin
+        } else if f.has_atom_attr("test") {
+            RunnableKind::Test {
+                name: name.to_string(),
+            }
+        } else {
+            return None;
+        };
+        Some(Runnable {
+            range: f.syntax().range(),
+            kind,
+        })
+    } else if let Some(m) = ast::Module::cast(item) {
+        if m.item_list()?
+            .items()
+            .map(ast::ModuleItem::syntax)
+            .filter_map(ast::FnDef::cast)
+            .any(|f| f.has_atom_attr("test"))
+        {
+            let postition = FilePosition {
+                file_id,
+                offset: m.syntax().range().start() + TextUnit::from_usize(1),
+            };
+            analysis.module_path(postition).ok()?.map(|path| Runnable {
+                range: m.syntax().range(),
+                kind: RunnableKind::TestMod { path },
+            })
+        } else {
+            None
+        }
+    } else {
+        None
+    }
+}