1 files changed, 89 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/runnables.rs b/crates/ra_ide_api/src/runnables.rs
new file mode 100644
index 000000000..98b1d2d55
--- /dev/null
+++ b/crates/ra_ide_api/src/runnables.rs
@@ -0,0 +1,89 @@
+use itertools::Itertools;
+use ra_syntax::{
+    TextRange, SyntaxNode,
+    ast::{self, AstNode, NameOwner, ModuleItemOwner},
+};
+use ra_db::{Cancelable, SyntaxDatabase};
+
+use crate::{db::RootDatabase, FileId};
+
+#[derive(Debug)]
+pub struct Runnable {
+    pub range: TextRange,
+    pub kind: RunnableKind,
+}
+
+#[derive(Debug)]
+pub enum RunnableKind {
+    Test { name: String },
+    TestMod { path: String },
+    Bin,
+}
+
+pub(crate) fn runnables(db: &RootDatabase, file_id: FileId) -> Cancelable<Vec<Runnable>> {
+    let source_file = db.source_file(file_id);
+    let res = source_file
+        .syntax()
+        .descendants()
+        .filter_map(|i| runnable(db, file_id, i))
+        .collect();
+    Ok(res)
+}
+
+fn runnable(db: &RootDatabase, file_id: FileId, item: &SyntaxNode) -> Option<Runnable> {
+    if let Some(fn_def) = ast::FnDef::cast(item) {
+        runnable_fn(fn_def)
+    } else if let Some(m) = ast::Module::cast(item) {
+        runnable_mod(db, file_id, m)
+    } else {
+        None
+    }
+}
+
+fn runnable_fn(fn_def: &ast::FnDef) -> Option<Runnable> {
+    let name = fn_def.name()?.text();
+    let kind = if name == "main" {
+        RunnableKind::Bin
+    } else if fn_def.has_atom_attr("test") {
+        RunnableKind::Test {
+            name: name.to_string(),
+        }
+    } else {
+        return None;
+    };
+    Some(Runnable {
+        range: fn_def.syntax().range(),
+        kind,
+    })
+}
+
+fn runnable_mod(db: &RootDatabase, file_id: FileId, module: &ast::Module) -> Option<Runnable> {
+    let has_test_function = module
+        .item_list()?
+        .items()
+        .filter_map(|it| match it.kind() {
+            ast::ModuleItemKind::FnDef(it) => Some(it),
+            _ => None,
+        })
+        .any(|f| f.has_atom_attr("test"));
+    if !has_test_function {
+        return None;
+    }
+    let range = module.syntax().range();
+    let module =
+        hir::source_binder::module_from_child_node(db, file_id, module.syntax()).ok()??;
+
+    // FIXME: thread cancellation instead of `.ok`ing
+    let path = module
+        .path_to_root(db)
+        .ok()?
+        .into_iter()
+        .rev()
+        .filter_map(|it| it.name(db).ok())
+        .filter_map(|it| it)
+        .join("::");
+    Some(Runnable {
+        range,
+        kind: RunnableKind::TestMod { path },
+    })
+}