Add a test for self field completion

Needed to add a default crate graph in the analysis for that.

crates/ra_analysis/src/completion/complete_dot.rs

@@ -72,6 +72,21 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_struct_field_completion_self() {
+        check_ref_completion(
+            r"
+            struct A { the_field: u32 }
+            impl A {
+                fn foo(self) {
+                    self.<|>
+                }
+            }
+            ",
+            r#"the_field"#,
+        );
+    }
+
     #[test]
     fn test_no_struct_field_completion_for_method_call() {
         check_ref_completion(

crates/ra_analysis/src/mock_analysis.rs

@@ -4,7 +4,7 @@ use relative_path::RelativePathBuf;
 use test_utils::{extract_offset, extract_range, parse_fixture, CURSOR_MARKER};
 use ra_db::mock::FileMap;
 
-use crate::{Analysis, AnalysisChange, AnalysisHost, FileId, FilePosition, FileRange, SourceRootId};
+use crate::{Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, FilePosition, FileRange, SourceRootId};
 
 /// Mock analysis is used in test to bootstrap an AnalysisHost/Analysis
 /// from a set of in-memory files.
@@ -87,12 +87,17 @@ impl MockAnalysis {
         let source_root = SourceRootId(0);
         let mut change = AnalysisChange::new();
         change.add_root(source_root, true);
+        let mut crate_graph = CrateGraph::default();
         for (path, contents) in self.files.into_iter() {
             assert!(path.starts_with('/'));
             let path = RelativePathBuf::from_path(&path[1..]).unwrap();
             let file_id = file_map.add(path.clone());
+            if path == "/lib.rs" || path == "/main.rs" {
+                crate_graph.add_crate_root(file_id);
+            }
             change.add_file(source_root, file_id, path, Arc::new(contents));
         }
+        change.set_crate_graph(crate_graph);
         // change.set_file_resolver(Arc::new(file_map));
         host.apply_change(change);
         host