1 files changed, 157 insertions, 0 deletions

diff --git a/crates/ra_analysis/src/module_map.rs b/crates/ra_analysis/src/module_map.rs
new file mode 100644
index 000000000..a21f55fff
--- /dev/null
+++ b/crates/ra_analysis/src/module_map.rs
@@ -0,0 +1,157 @@
+use std::sync::Arc;
+use {
+    FileId,
+    db::{
+        Query, QueryRegistry, QueryCtx,
+        file_set
+    },
+    queries::file_syntax,
+    descriptors::{ModuleDescriptor, ModuleTreeDescriptor},
+};
+
+pub(crate) fn register_queries(reg: &mut QueryRegistry) {
+    reg.add(MODULE_DESCR, "MODULE_DESCR");
+    reg.add(MODULE_TREE, "MODULE_TREE");
+}
+
+pub(crate) fn module_tree(ctx: QueryCtx) -> Arc<ModuleTreeDescriptor> {
+    ctx.get(MODULE_TREE, ())
+}
+
+const MODULE_DESCR: Query<FileId, ModuleDescriptor> = Query(30, |ctx, &file_id| {
+    let file = file_syntax(ctx, file_id);
+    ModuleDescriptor::new(file.ast())
+});
+
+const MODULE_TREE: Query<(), ModuleTreeDescriptor> = Query(31, |ctx, _| {
+    let file_set = file_set(ctx);
+    let mut files = Vec::new();
+    for &file_id in file_set.0.iter() {
+        let module_descr = ctx.get(MODULE_DESCR, file_id);
+        files.push((file_id, module_descr));
+    }
+    ModuleTreeDescriptor::new(files.iter().map(|(file_id, descr)| (*file_id, &**descr)), &file_set.1)
+});
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashMap;
+    use im;
+    use relative_path::{RelativePath, RelativePathBuf};
+    use {
+        db::{Db},
+        imp::FileResolverImp,
+        FileId, FileResolver,
+    };
+    use super::*;
+
+    #[derive(Debug)]
+    struct FileMap(im::HashMap<FileId, RelativePathBuf>);
+
+    impl FileResolver for FileMap {
+        fn file_stem(&self, file_id: FileId) -> String {
+            self.0[&file_id].file_stem().unwrap().to_string()
+        }
+        fn resolve(&self, file_id: FileId, rel: &RelativePath) -> Option<FileId> {
+            let path = self.0[&file_id].join(rel).normalize();
+            self.0.iter()
+                .filter_map(|&(id, ref p)| Some(id).filter(|_| p == &path))
+                .next()
+        }
+    }
+
+    struct Fixture {
+        next_file_id: u32,
+        fm: im::HashMap<FileId, RelativePathBuf>,
+        db: Db,
+    }
+
+    impl Fixture {
+        fn new() -> Fixture {
+            Fixture {
+                next_file_id: 1,
+                fm: im::HashMap::new(),
+                db: Db::new(),
+            }
+        }
+        fn add_file(&mut self, path: &str, text: &str) -> FileId {
+            assert!(path.starts_with("/"));
+            let file_id = FileId(self.next_file_id);
+            self.next_file_id += 1;
+            self.fm.insert(file_id, RelativePathBuf::from(&path[1..]));
+            let mut new_state = self.db.state().clone();
+            new_state.file_map.insert(file_id, Arc::new(text.to_string()));
+            new_state.file_resolver = FileResolverImp::new(
+                Arc::new(FileMap(self.fm.clone()))
+            );
+            self.db = self.db.with_changes(new_state, &[file_id], true);
+            file_id
+        }
+        fn remove_file(&mut self, file_id: FileId) {
+            self.fm.remove(&file_id);
+            let mut new_state = self.db.state().clone();
+            new_state.file_map.remove(&file_id);
+            new_state.file_resolver = FileResolverImp::new(
+                Arc::new(FileMap(self.fm.clone()))
+            );
+            self.db = self.db.with_changes(new_state, &[file_id], true);
+        }
+        fn change_file(&mut self, file_id: FileId, new_text: &str) {
+            let mut new_state = self.db.state().clone();
+            new_state.file_map.insert(file_id, Arc::new(new_text.to_string()));
+            self.db = self.db.with_changes(new_state, &[file_id], false);
+        }
+        fn check_parent_modules(
+            &self,
+            file_id: FileId,
+            expected: &[FileId],
+            queries: &[(&'static str, u64)]
+        ) {
+            let (tree, events) = self.db.trace_query(|ctx| module_tree(ctx));
+            let actual = tree.parent_modules(file_id)
+                .into_iter()
+                .map(|link| link.owner(&tree))
+                .collect::<Vec<_>>();
+            assert_eq!(actual.as_slice(), expected);
+            let mut counts = HashMap::new();
+            events.into_iter()
+               .for_each(|event| *counts.entry(event).or_insert(0) += 1);
+            for &(query_id, expected_count) in queries.iter() {
+                let actual_count = *counts.get(&query_id).unwrap_or(&0);
+                assert_eq!(
+                    actual_count,
+                    expected_count,
+                    "counts for {} differ",
+                    query_id,
+                )
+            }
+
+        }
+    }
+
+    #[test]
+    fn test_parent_module() {
+        let mut f = Fixture::new();
+        let foo = f.add_file("/foo.rs", "");
+        f.check_parent_modules(foo, &[], &[("MODULE_DESCR", 1)]);
+
+        let lib = f.add_file("/lib.rs", "mod foo;");
+        f.check_parent_modules(foo, &[lib], &[("MODULE_DESCR", 1)]);
+        f.check_parent_modules(foo, &[lib], &[("MODULE_DESCR", 0)]);
+
+        f.change_file(lib, "");
+        f.check_parent_modules(foo, &[], &[("MODULE_DESCR", 1)]);
+
+        f.change_file(lib, "mod foo;");
+        f.check_parent_modules(foo, &[lib], &[("MODULE_DESCR", 1)]);
+
+        f.change_file(lib, "mod bar;");
+        f.check_parent_modules(foo, &[], &[("MODULE_DESCR", 1)]);
+
+        f.change_file(lib, "mod foo;");
+        f.check_parent_modules(foo, &[lib], &[("MODULE_DESCR", 1)]);
+
+        f.remove_file(lib);
+        f.check_parent_modules(foo, &[], &[("MODULE_DESCR", 0)]);
+    }
+}