1 files changed, 176 insertions, 0 deletions

diff --git a/crates/ide_completion/src/tests.rs b/crates/ide_completion/src/tests.rs
new file mode 100644
index 000000000..1495924ea
--- /dev/null
+++ b/crates/ide_completion/src/tests.rs
@@ -0,0 +1,176 @@
+mod item_list;
+
+use hir::{PrefixKind, Semantics};
+use ide_db::{
+    base_db::{fixture::ChangeFixture, FileLoader, FilePosition},
+    helpers::{
+        insert_use::{ImportGranularity, InsertUseConfig},
+        SnippetCap,
+    },
+    RootDatabase,
+};
+use itertools::Itertools;
+use stdx::{format_to, trim_indent};
+use syntax::{AstNode, NodeOrToken, SyntaxElement};
+use test_utils::assert_eq_text;
+
+use crate::{item::CompletionKind, CompletionConfig, CompletionItem};
+
+pub(crate) const TEST_CONFIG: CompletionConfig = CompletionConfig {
+    enable_postfix_completions: true,
+    enable_imports_on_the_fly: true,
+    enable_self_on_the_fly: true,
+    add_call_parenthesis: true,
+    add_call_argument_snippets: true,
+    snippet_cap: SnippetCap::new(true),
+    insert_use: InsertUseConfig {
+        granularity: ImportGranularity::Crate,
+        prefix_kind: PrefixKind::Plain,
+        enforce_granularity: true,
+        group: true,
+    },
+};
+
+fn completion_list(code: &str) -> String {
+    completion_list_with_config(TEST_CONFIG, code)
+}
+
+fn completion_list_with_config(config: CompletionConfig, code: &str) -> String {
+    render_completion_list(get_all_items(config, code))
+}
+
+/// Creates analysis from a multi-file fixture, returns positions marked with $0.
+pub(crate) fn position(ra_fixture: &str) -> (RootDatabase, FilePosition) {
+    let change_fixture = ChangeFixture::parse(ra_fixture);
+    let mut database = RootDatabase::default();
+    database.apply_change(change_fixture.change);
+    let (file_id, range_or_offset) = change_fixture.file_position.expect("expected a marker ($0)");
+    let offset = range_or_offset.expect_offset();
+    (database, FilePosition { file_id, offset })
+}
+
+pub(crate) fn do_completion(code: &str, kind: CompletionKind) -> Vec<CompletionItem> {
+    do_completion_with_config(TEST_CONFIG, code, kind)
+}
+
+pub(crate) fn do_completion_with_config(
+    config: CompletionConfig,
+    code: &str,
+    kind: CompletionKind,
+) -> Vec<CompletionItem> {
+    get_all_items(config, code)
+        .into_iter()
+        .filter(|c| c.completion_kind == kind)
+        .sorted_by(|l, r| l.label().cmp(r.label()))
+        .collect()
+}
+
+pub(crate) fn filtered_completion_list(code: &str, kind: CompletionKind) -> String {
+    filtered_completion_list_with_config(TEST_CONFIG, code, kind)
+}
+
+pub(crate) fn filtered_completion_list_with_config(
+    config: CompletionConfig,
+    code: &str,
+    kind: CompletionKind,
+) -> String {
+    let kind_completions: Vec<CompletionItem> =
+        get_all_items(config, code).into_iter().filter(|c| c.completion_kind == kind).collect();
+    render_completion_list(kind_completions)
+}
+
+fn render_completion_list(completions: Vec<CompletionItem>) -> String {
+    fn monospace_width(s: &str) -> usize {
+        s.chars().count()
+    }
+    let label_width =
+        completions.iter().map(|it| monospace_width(it.label())).max().unwrap_or_default().min(16);
+    completions
+        .into_iter()
+        .map(|it| {
+            let tag = it.kind().unwrap().tag();
+            let var_name = format!("{} {}", tag, it.label());
+            let mut buf = var_name;
+            if let Some(detail) = it.detail() {
+                let width = label_width.saturating_sub(monospace_width(it.label()));
+                format_to!(buf, "{:width$} {}", "", detail, width = width);
+            }
+            if it.deprecated() {
+                format_to!(buf, " DEPRECATED");
+            }
+            format_to!(buf, "\n");
+            buf
+        })
+        .collect()
+}
+
+pub(crate) fn check_edit(what: &str, ra_fixture_before: &str, ra_fixture_after: &str) {
+    check_edit_with_config(TEST_CONFIG, what, ra_fixture_before, ra_fixture_after)
+}
+
+pub(crate) fn check_edit_with_config(
+    config: CompletionConfig,
+    what: &str,
+    ra_fixture_before: &str,
+    ra_fixture_after: &str,
+) {
+    let ra_fixture_after = trim_indent(ra_fixture_after);
+    let (db, position) = position(ra_fixture_before);
+    let completions: Vec<CompletionItem> =
+        crate::completions(&db, &config, position).unwrap().into();
+    let (completion,) = completions
+        .iter()
+        .filter(|it| it.lookup() == what)
+        .collect_tuple()
+        .unwrap_or_else(|| panic!("can't find {:?} completion in {:#?}", what, completions));
+    let mut actual = db.file_text(position.file_id).to_string();
+
+    let mut combined_edit = completion.text_edit().to_owned();
+    if let Some(import_text_edit) =
+        completion.import_to_add().and_then(|edit| edit.to_text_edit(config.insert_use))
+    {
+        combined_edit.union(import_text_edit).expect(
+            "Failed to apply completion resolve changes: change ranges overlap, but should not",
+        )
+    }
+
+    combined_edit.apply(&mut actual);
+    assert_eq_text!(&ra_fixture_after, &actual)
+}
+
+pub(crate) fn check_pattern_is_applicable(code: &str, check: impl FnOnce(SyntaxElement) -> bool) {
+    let (db, pos) = position(code);
+
+    let sema = Semantics::new(&db);
+    let original_file = sema.parse(pos.file_id);
+    let token = original_file.syntax().token_at_offset(pos.offset).left_biased().unwrap();
+    assert!(check(NodeOrToken::Token(token)));
+}
+
+pub(crate) fn check_pattern_is_not_applicable(code: &str, check: fn(SyntaxElement) -> bool) {
+    let (db, pos) = position(code);
+    let sema = Semantics::new(&db);
+    let original_file = sema.parse(pos.file_id);
+    let token = original_file.syntax().token_at_offset(pos.offset).left_biased().unwrap();
+    assert!(!check(NodeOrToken::Token(token)));
+}
+
+pub(crate) fn get_all_items(config: CompletionConfig, code: &str) -> Vec<CompletionItem> {
+    let (db, position) = position(code);
+    crate::completions(&db, &config, position).unwrap().into()
+}
+
+fn check_no_completion(ra_fixture: &str) {
+    let (db, position) = position(ra_fixture);
+
+    assert!(
+        crate::completions(&db, &TEST_CONFIG, position).is_none(),
+        "Completions were generated, but weren't expected"
+    );
+}
+
+#[test]
+fn test_no_completions_required() {
+    cov_mark::check!(no_completion_required);
+    check_no_completion(r#"fn foo() { for i i$0 }"#);
+}