Merge #1572

1572: Provide completion in struct patterns r=matklad a=viorina



Co-authored-by: Ekaterina Babshukova <[email protected]>

1 files changed, 94 insertions, 0 deletions

diff --git a/crates/ra_ide_api/src/completion/complete_struct_pattern.rs b/crates/ra_ide_api/src/completion/complete_struct_pattern.rs
new file mode 100644
index 000000000..d0dde5930
--- /dev/null
+++ b/crates/ra_ide_api/src/completion/complete_struct_pattern.rs
@@ -0,0 +1,94 @@
+use hir::Substs;
+
+use crate::completion::{CompletionContext, Completions};
+
+pub(super) fn complete_struct_pattern(acc: &mut Completions, ctx: &CompletionContext) {
+    let (ty, variant) = match ctx.struct_lit_pat.as_ref().and_then(|it| {
+        Some((
+            ctx.analyzer.type_of_pat(ctx.db, &it.clone().into())?,
+            ctx.analyzer.resolve_struct_pattern(it)?,
+        ))
+    }) {
+        Some(it) => it,
+        _ => return,
+    };
+    let substs = &ty.substs().unwrap_or_else(Substs::empty);
+
+    for field in variant.fields(ctx.db) {
+        acc.add_field(ctx, field, substs);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::completion::{do_completion, CompletionItem, CompletionKind};
+    use insta::assert_debug_snapshot_matches;
+
+    fn complete(code: &str) -> Vec<CompletionItem> {
+        do_completion(code, CompletionKind::Reference)
+    }
+
+    #[test]
+    fn test_struct_pattern_field() {
+        let completions = complete(
+            r"
+            struct S { foo: u32 }
+
+            fn process(f: S) {
+                match f {
+                    S { f<|>: 92 } => (),
+                }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "foo",
+       ⋮        source_range: [117; 118),
+       ⋮        delete: [117; 118),
+       ⋮        insert: "foo",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
+
+    #[test]
+    fn test_struct_pattern_enum_variant() {
+        let completions = complete(
+            r"
+            enum E {
+                S { foo: u32, bar: () }
+            }
+
+            fn process(e: E) {
+                match e {
+                    E::S { <|> } => (),
+                }
+            }
+            ",
+        );
+        assert_debug_snapshot_matches!(completions, @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "bar",
+       ⋮        source_range: [161; 161),
+       ⋮        delete: [161; 161),
+       ⋮        insert: "bar",
+       ⋮        kind: Field,
+       ⋮        detail: "()",
+       ⋮    },
+       ⋮    CompletionItem {
+       ⋮        label: "foo",
+       ⋮        source_range: [161; 161),
+       ⋮        delete: [161; 161),
+       ⋮        insert: "foo",
+       ⋮        kind: Field,
+       ⋮        detail: "u32",
+       ⋮    },
+       ⋮]
+        "###);
+    }
+}