Start refactoring ide_completion tests

9 files changed, 302 insertions, 247 deletions

diff --git a/crates/ide_completion/src/completions.rs b/crates/ide_completion/src/completions.rs
index 783305005..cba5eb0c6 100644
--- a/crates/ide_completion/src/completions.rs
+++ b/crates/ide_completion/src/completions.rs
@@ -41,9 +41,9 @@ pub struct Completions {
     buf: Vec<CompletionItem>,
 }
 
-impl Into<Vec<CompletionItem>> for Completions {
-    fn into(self) -> Vec<CompletionItem> {
-        self.buf
+impl From<Completions> for Vec<CompletionItem> {
+    fn from(val: Completions) -> Self {
+        val.buf
     }
 }
 
@@ -74,35 +74,6 @@ impl Completions {
         items.into_iter().for_each(|item| self.add(item.into()))
     }
 
-    pub(crate) fn add_field(
-        &mut self,
-        ctx: &CompletionContext,
-        receiver: Option<hir::Name>,
-        field: hir::Field,
-        ty: &hir::Type,
-    ) {
-        let item = render_field(RenderContext::new(ctx), receiver, field, ty);
-        self.add(item);
-    }
-
-    pub(crate) fn add_tuple_field(
-        &mut self,
-        ctx: &CompletionContext,
-        receiver: Option<hir::Name>,
-        field: usize,
-        ty: &hir::Type,
-    ) {
-        let item = render_tuple_field(RenderContext::new(ctx), receiver, field, ty);
-        self.add(item);
-    }
-
-    pub(crate) fn add_static_lifetime(&mut self, ctx: &CompletionContext) {
-        let mut item =
-            CompletionItem::new(CompletionKind::Reference, ctx.source_range(), "'static");
-        item.kind(CompletionItemKind::SymbolKind(SymbolKind::LifetimeParam));
-        self.add(item.build());
-    }
-
     pub(crate) fn add_resolution(
         &mut self,
         ctx: &CompletionContext,
@@ -144,72 +115,102 @@ impl Completions {
         self.add_opt(render_method(RenderContext::new(ctx), None, receiver, local_name, func));
     }
 
-    pub(crate) fn add_variant_pat(
+    pub(crate) fn add_const(&mut self, ctx: &CompletionContext, constant: hir::Const) {
+        self.add_opt(render_const(RenderContext::new(ctx), constant));
+    }
+
+    pub(crate) fn add_type_alias(&mut self, ctx: &CompletionContext, type_alias: hir::TypeAlias) {
+        self.add_opt(render_type_alias(RenderContext::new(ctx), type_alias));
+    }
+
+    pub(crate) fn add_type_alias_with_eq(
         &mut self,
         ctx: &CompletionContext,
-        variant: hir::Variant,
-        local_name: Option<hir::Name>,
+        type_alias: hir::TypeAlias,
     ) {
-        self.add_opt(render_variant_pat(RenderContext::new(ctx), variant, local_name, None));
+        self.add_opt(render_type_alias_with_eq(RenderContext::new(ctx), type_alias));
     }
 
-    pub(crate) fn add_qualified_variant_pat(
+    pub(crate) fn add_qualified_enum_variant(
         &mut self,
         ctx: &CompletionContext,
         variant: hir::Variant,
         path: hir::ModPath,
     ) {
-        self.add_opt(render_variant_pat(RenderContext::new(ctx), variant, None, Some(path)));
+        let item = render_variant(RenderContext::new(ctx), None, None, variant, Some(path));
+        self.add(item);
     }
 
-    pub(crate) fn add_struct_pat(
+    pub(crate) fn add_enum_variant(
         &mut self,
         ctx: &CompletionContext,
-        strukt: hir::Struct,
+        variant: hir::Variant,
         local_name: Option<hir::Name>,
     ) {
-        self.add_opt(render_struct_pat(RenderContext::new(ctx), strukt, local_name));
+        let item = render_variant(RenderContext::new(ctx), None, local_name, variant, None);
+        self.add(item);
     }
 
-    pub(crate) fn add_const(&mut self, ctx: &CompletionContext, constant: hir::Const) {
-        self.add_opt(render_const(RenderContext::new(ctx), constant));
+    pub(crate) fn add_field(
+        &mut self,
+        ctx: &CompletionContext,
+        receiver: Option<hir::Name>,
+        field: hir::Field,
+        ty: &hir::Type,
+    ) {
+        let item = render_field(RenderContext::new(ctx), receiver, field, ty);
+        self.add(item);
     }
 
-    pub(crate) fn add_type_alias(&mut self, ctx: &CompletionContext, type_alias: hir::TypeAlias) {
-        self.add_opt(render_type_alias(RenderContext::new(ctx), type_alias));
+    pub(crate) fn add_tuple_field(
+        &mut self,
+        ctx: &CompletionContext,
+        receiver: Option<hir::Name>,
+        field: usize,
+        ty: &hir::Type,
+    ) {
+        let item = render_tuple_field(RenderContext::new(ctx), receiver, field, ty);
+        self.add(item);
     }
 
-    pub(crate) fn add_type_alias_with_eq(
+    pub(crate) fn add_static_lifetime(&mut self, ctx: &CompletionContext) {
+        let mut item =
+            CompletionItem::new(CompletionKind::Reference, ctx.source_range(), "'static");
+        item.kind(CompletionItemKind::SymbolKind(SymbolKind::LifetimeParam));
+        self.add(item.build());
+    }
+
+    pub(crate) fn add_variant_pat(
         &mut self,
         ctx: &CompletionContext,
-        type_alias: hir::TypeAlias,
+        variant: hir::Variant,
+        local_name: Option<hir::Name>,
     ) {
-        self.add_opt(render_type_alias_with_eq(RenderContext::new(ctx), type_alias));
+        self.add_opt(render_variant_pat(RenderContext::new(ctx), variant, local_name, None));
     }
 
-    pub(crate) fn add_qualified_enum_variant(
+    pub(crate) fn add_qualified_variant_pat(
         &mut self,
         ctx: &CompletionContext,
         variant: hir::Variant,
         path: hir::ModPath,
     ) {
-        let item = render_variant(RenderContext::new(ctx), None, None, variant, Some(path));
-        self.add(item);
+        self.add_opt(render_variant_pat(RenderContext::new(ctx), variant, None, Some(path)));
     }
 
-    pub(crate) fn add_enum_variant(
+    pub(crate) fn add_struct_pat(
         &mut self,
         ctx: &CompletionContext,
-        variant: hir::Variant,
+        strukt: hir::Struct,
         local_name: Option<hir::Name>,
     ) {
-        let item = render_variant(RenderContext::new(ctx), None, local_name, variant, None);
-        self.add(item);
+        self.add_opt(render_struct_pat(RenderContext::new(ctx), strukt, local_name));
     }
 }
 
 /// Calls the callback for each variant of the provided enum with the path to the variant.
-fn complete_enum_variants(
+/// Skips variants that are visible with single segment paths.
+fn enum_variants_with_paths(
     acc: &mut Completions,
     ctx: &CompletionContext,
     enum_: hir::Enum,
diff --git a/crates/ide_completion/src/completions/keyword.rs b/crates/ide_completion/src/completions/keyword.rs
index 0fccbeccf..2c42438d6 100644
--- a/crates/ide_completion/src/completions/keyword.rs
+++ b/crates/ide_completion/src/completions/keyword.rs
@@ -231,30 +231,6 @@ mod tests {
     }
 
     #[test]
-    fn test_keywords_at_source_file_level() {
-        check(
-            r"m$0",
-            expect![[r#"
-                kw pub(crate)
-                kw pub
-                kw unsafe
-                kw fn
-                kw const
-                kw type
-                kw use
-                kw impl
-                kw trait
-                kw static
-                kw extern
-                kw mod
-                kw enum
-                kw struct
-                kw union
-            "#]],
-        );
-    }
-
-    #[test]
     fn test_keywords_in_function() {
         check(
             r"fn quux() { $0 }",
@@ -443,18 +419,6 @@ fn quux() -> i32 {
     }
 
     #[test]
-    fn test_keywords_after_unsafe_in_item_list() {
-        check(
-            r"unsafe $0",
-            expect![[r#"
-                kw fn
-                kw trait
-                kw impl
-            "#]],
-        );
-    }
-
-    #[test]
     fn test_keywords_after_unsafe_in_block_expr() {
         check(
             r"fn my_fn() { unsafe $0 }",
diff --git a/crates/ide_completion/src/completions/pattern.rs b/crates/ide_completion/src/completions/pattern.rs
index 1daa8595a..e45b2a1ea 100644
--- a/crates/ide_completion/src/completions/pattern.rs
+++ b/crates/ide_completion/src/completions/pattern.rs
@@ -13,7 +13,7 @@ pub(crate) fn complete_pattern(acc: &mut Completions, ctx: &CompletionContext) {
         if let Some(hir::Adt::Enum(e)) =
             ctx.expected_type.as_ref().and_then(|ty| ty.strip_references().as_adt())
         {
-            super::complete_enum_variants(acc, ctx, e, |acc, ctx, variant, path| {
+            super::enum_variants_with_paths(acc, ctx, e, |acc, ctx, variant, path| {
                 acc.add_qualified_variant_pat(ctx, variant, path.clone());
                 acc.add_qualified_enum_variant(ctx, variant, path);
             });
diff --git a/crates/ide_completion/src/completions/qualified_path.rs b/crates/ide_completion/src/completions/qualified_path.rs
index 1643eeed4..165b9e6a5 100644
--- a/crates/ide_completion/src/completions/qualified_path.rs
+++ b/crates/ide_completion/src/completions/qualified_path.rs
@@ -714,24 +714,6 @@ impl MyStruct {
     }
 
     #[test]
-    fn completes_in_item_list() {
-        check(
-            r#"
-struct MyStruct {}
-#[macro_export]
-macro_rules! foo {}
-mod bar {}
-
-crate::$0
-"#,
-            expect![[r#"
-                md bar
-                ma foo!(…) #[macro_export] macro_rules! foo
-            "#]],
-        )
-    }
-
-    #[test]
     fn test_super_super_completion() {
         check(
             r#"
diff --git a/crates/ide_completion/src/completions/snippet.rs b/crates/ide_completion/src/completions/snippet.rs
index b9862de67..5560f1acf 100644
--- a/crates/ide_completion/src/completions/snippet.rs
+++ b/crates/ide_completion/src/completions/snippet.rs
@@ -105,21 +105,4 @@ mod tests {
         check(r#"fn foo(x: i32) { ::foo$0 }"#, expect![[""]]);
         check(r#"fn foo(x: i32) { ::$0 }"#, expect![[""]]);
     }
-
-    #[test]
-    fn completes_snippets_in_items() {
-        check(
-            r#"
-#[cfg(test)]
-mod tests {
-    $0
-}
-"#,
-            expect![[r#"
-                sn tmod (Test module)
-                sn tfn (Test function)
-                sn macro_rules
-            "#]],
-        )
-    }
 }
diff --git a/crates/ide_completion/src/completions/unqualified_path.rs b/crates/ide_completion/src/completions/unqualified_path.rs
index b5af1c810..2c623bf7a 100644
--- a/crates/ide_completion/src/completions/unqualified_path.rs
+++ b/crates/ide_completion/src/completions/unqualified_path.rs
@@ -40,7 +40,7 @@ pub(crate) fn complete_unqualified_path(acc: &mut Completions, ctx: &CompletionC
         if let Some(hir::Adt::Enum(e)) =
             ctx.expected_type.as_ref().and_then(|ty| ty.strip_references().as_adt())
         {
-            super::complete_enum_variants(acc, ctx, e, |acc, ctx, variant, path| {
+            super::enum_variants_with_paths(acc, ctx, e, |acc, ctx, variant, path| {
                 acc.add_qualified_enum_variant(ctx, variant, path)
             });
         }
diff --git a/crates/ide_completion/src/lib.rs b/crates/ide_completion/src/lib.rs
index 18983aa01..be6442426 100644
--- a/crates/ide_completion/src/lib.rs
+++ b/crates/ide_completion/src/lib.rs
@@ -1,14 +1,16 @@
 //! `completions` crate provides utilities for generating completions of user input.
 
+mod completions;
 mod config;
-mod item;
 mod context;
+mod item;
 mod patterns;
-#[cfg(test)]
-mod test_utils;
 mod render;
 
-mod completions;
+#[cfg(test)]
+mod tests;
+#[cfg(test)]
+mod test_utils;
 
 use completions::flyimport::position_for_import;
 use ide_db::{
@@ -141,6 +143,7 @@ pub fn completions(
     let ctx = CompletionContext::new(db, position, config)?;
 
     if ctx.no_completion_required() {
+        cov_mark::hit!(no_completion_required);
         // No work required here.
         return None;
     }
@@ -200,117 +203,3 @@ pub fn resolve_completion_edits(
 
     ImportEdit { import, scope }.to_text_edit(config.insert_use).map(|edit| vec![edit])
 }
-
-#[cfg(test)]
-mod tests {
-    use crate::test_utils::{self, TEST_CONFIG};
-
-    struct DetailAndDocumentation<'a> {
-        detail: &'a str,
-        documentation: &'a str,
-    }
-
-    fn check_detail_and_documentation(ra_fixture: &str, expected: DetailAndDocumentation) {
-        let (db, position) = test_utils::position(ra_fixture);
-        let config = TEST_CONFIG;
-        let completions: Vec<_> = crate::completions(&db, &config, position).unwrap().into();
-        for item in completions {
-            if item.detail() == Some(expected.detail) {
-                let opt = item.documentation();
-                let doc = opt.as_ref().map(|it| it.as_str());
-                assert_eq!(doc, Some(expected.documentation));
-                return;
-            }
-        }
-        panic!("completion detail not found: {}", expected.detail)
-    }
-
-    fn check_no_completion(ra_fixture: &str) {
-        let (db, position) = test_utils::position(ra_fixture);
-        let config = TEST_CONFIG;
-
-        let completions: Option<Vec<String>> = crate::completions(&db, &config, position)
-            .and_then(|completions| {
-                let completions: Vec<_> = completions.into();
-                if completions.is_empty() {
-                    None
-                } else {
-                    Some(completions)
-                }
-            })
-            .map(|completions| {
-                completions.into_iter().map(|completion| format!("{:?}", completion)).collect()
-            });
-
-        // `assert_eq` instead of `assert!(completions.is_none())` to get the list of completions if test will panic.
-        assert_eq!(completions, None, "Completions were generated, but weren't expected");
-    }
-
-    #[test]
-    fn test_completion_detail_from_macro_generated_struct_fn_doc_attr() {
-        check_detail_and_documentation(
-            r#"
-macro_rules! bar {
-    () => {
-        struct Bar;
-        impl Bar {
-            #[doc = "Do the foo"]
-            fn foo(&self) {}
-        }
-    }
-}
-
-bar!();
-
-fn foo() {
-    let bar = Bar;
-    bar.fo$0;
-}
-"#,
-            DetailAndDocumentation { detail: "fn(&self)", documentation: "Do the foo" },
-        );
-    }
-
-    #[test]
-    fn test_completion_detail_from_macro_generated_struct_fn_doc_comment() {
-        check_detail_and_documentation(
-            r#"
-macro_rules! bar {
-    () => {
-        struct Bar;
-        impl Bar {
-            /// Do the foo
-            fn foo(&self) {}
-        }
-    }
-}
-
-bar!();
-
-fn foo() {
-    let bar = Bar;
-    bar.fo$0;
-}
-"#,
-            DetailAndDocumentation { detail: "fn(&self)", documentation: "Do the foo" },
-        );
-    }
-
-    #[test]
-    fn test_no_completions_required() {
-        // There must be no hint for 'in' keyword.
-        check_no_completion(r#"fn foo() { for i i$0 }"#);
-        // After 'in' keyword hints may be spawned.
-        check_detail_and_documentation(
-            r#"
-/// Do the foo
-fn foo() -> &'static str { "foo" }
-
-fn bar() {
-    for c in fo$0
-}
-"#,
-            DetailAndDocumentation { detail: "fn() -> &str", documentation: "Do the foo" },
-        );
-    }
-}
diff --git a/crates/ide_completion/src/tests.rs b/crates/ide_completion/src/tests.rs
new file mode 100644
index 000000000..4485a908e
--- /dev/null
+++ b/crates/ide_completion/src/tests.rs
@@ -0,0 +1,64 @@
+mod item_list;
+
+use expect_test::Expect;
+use stdx::format_to;
+
+use crate::{
+    test_utils::{self, get_all_items, TEST_CONFIG},
+    CompletionConfig, CompletionItem,
+};
+
+fn completion_list(code: &str) -> String {
+    completion_list_with_config(TEST_CONFIG, code)
+}
+
+fn completion_list_with_config(config: CompletionConfig, code: &str) -> String {
+    fn monospace_width(s: &str) -> usize {
+        s.chars().count()
+    }
+
+    let kind_completions: Vec<CompletionItem> = get_all_items(config, code).into_iter().collect();
+    let label_width = kind_completions
+        .iter()
+        .map(|it| monospace_width(it.label()))
+        .max()
+        .unwrap_or_default()
+        .min(16);
+    kind_completions
+        .into_iter()
+        .map(|it| {
+            let tag = it.kind().unwrap().tag();
+            let var_name = format!("{} {}", tag, it.label());
+            let mut buf = var_name;
+            if let Some(detail) = it.detail() {
+                let width = label_width.saturating_sub(monospace_width(it.label()));
+                format_to!(buf, "{:width$} {}", "", detail, width = width);
+            }
+            if it.deprecated() {
+                format_to!(buf, " DEPRECATED");
+            }
+            format_to!(buf, "\n");
+            buf
+        })
+        .collect()
+}
+
+fn check(ra_fixture: &str, expect: Expect) {
+    let actual = completion_list(ra_fixture);
+    expect.assert_eq(&actual)
+}
+
+fn check_no_completion(ra_fixture: &str) {
+    let (db, position) = test_utils::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 }"#);
+}
diff --git a/crates/ide_completion/src/tests/item_list.rs b/crates/ide_completion/src/tests/item_list.rs
new file mode 100644
index 000000000..bd060a632
--- /dev/null
+++ b/crates/ide_completion/src/tests/item_list.rs
@@ -0,0 +1,172 @@
+use expect_test::expect;
+
+use crate::tests::check;
+
+#[test]
+fn in_mod_item_list() {
+    check(
+        r#"mod tests {
+    $0
+}
+"#,
+        expect![[r#"
+            kw pub(crate)
+            kw pub
+            kw unsafe
+            kw fn
+            kw const
+            kw type
+            kw use
+            kw impl
+            kw trait
+            kw static
+            kw extern
+            kw mod
+            kw enum
+            kw struct
+            kw union
+            sn tmod (Test module)
+            sn tfn (Test function)
+            sn macro_rules
+        "#]],
+    )
+}
+
+#[test]
+fn in_source_file_item_list() {
+    check(
+        r#"
+enum Enum { Variant }
+struct MyStruct {}
+#[macro_export]
+macro_rules! foo {}
+mod bar {}
+const CONST: () = ();
+
+$0"#,
+        expect![[r##"
+            kw pub(crate)
+            kw pub
+            kw unsafe
+            kw fn
+            kw const
+            kw type
+            kw use
+            kw impl
+            kw trait
+            kw static
+            kw extern
+            kw mod
+            kw enum
+            kw struct
+            kw union
+            sn tmod (Test module)
+            sn tfn (Test function)
+            sn macro_rules
+            md bar
+            ma foo!(…)          #[macro_export] macro_rules! foo
+            ma foo!(…)          #[macro_export] macro_rules! foo
+        "##]],
+    )
+}
+
+#[test]
+fn in_qualified_path() {
+    check(
+        r#"
+enum Enum { Variant }
+struct MyStruct {}
+#[macro_export]
+macro_rules! foo {}
+mod bar {}
+const CONST: () = ();
+
+crate::$0"#,
+        expect![[r##"
+            kw pub(crate)
+            kw pub
+            kw unsafe
+            kw fn
+            kw const
+            kw type
+            kw use
+            kw impl
+            kw trait
+            kw static
+            kw extern
+            kw mod
+            kw enum
+            kw struct
+            kw union
+            sn tmod (Test module)
+            sn tfn (Test function)
+            sn macro_rules
+            md bar
+            ma foo!(…)          #[macro_export] macro_rules! foo
+        "##]],
+    )
+}
+
+#[test]
+fn after_unsafe_token() {
+    check(
+        r#"
+enum Enum { Variant }
+struct MyStruct {}
+#[macro_export]
+macro_rules! foo {}
+mod bar {}
+const CONST: () = ();
+
+unsafe $0"#,
+        expect![[r##"
+            kw fn
+            kw trait
+            kw impl
+            sn tmod (Test module)
+            sn tfn (Test function)
+            sn macro_rules
+            md bar
+            ma foo!(…)          #[macro_export] macro_rules! foo
+            ma foo!(…)          #[macro_export] macro_rules! foo
+        "##]],
+    );
+}
+
+#[test]
+fn after_visibility() {
+    check(
+        r#"
+enum Enum { Variant }
+struct MyStruct {}
+#[macro_export]
+macro_rules! foo {}
+mod bar {}
+const CONST: () = ();
+
+pub $0"#,
+        expect![[r##"
+            kw pub(crate)
+            kw pub
+            kw unsafe
+            kw fn
+            kw const
+            kw type
+            kw use
+            kw impl
+            kw trait
+            kw static
+            kw extern
+            kw mod
+            kw enum
+            kw struct
+            kw union
+            sn tmod (Test module)
+            sn tfn (Test function)
+            sn macro_rules
+            md bar
+            ma foo!(…)          #[macro_export] macro_rules! foo
+            ma foo!(…)          #[macro_export] macro_rules! foo
+        "##]],
+    );
+}