From 1022672af0467edf480f50398989c3f8016ccd10 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Thu, 15 Oct 2020 17:03:52 +0200
Subject: Diagnose shorthand in patterns as well

---
 crates/ide/src/diagnostics.rs | 99 ++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 94 insertions(+), 5 deletions(-)

(limited to 'crates/ide')

diff --git a/crates/ide/src/diagnostics.rs b/crates/ide/src/diagnostics.rs
index d3d8c86b5..c36c321f2 100644
--- a/crates/ide/src/diagnostics.rs
+++ b/crates/ide/src/diagnostics.rs
@@ -192,7 +192,8 @@ fn check_field_shorthand(acc: &mut Vec<Diagnostic>, file_id: FileId, node: &Synt
     match_ast! {
         match node {
             ast::RecordExpr(it) => check_expr_field_shorthand(acc, file_id, it),
-            _ => None
+            ast::RecordPat(it) => check_pat_field_shorthand(acc, file_id, it),
+            _ => ()
         }
     };
 }
@@ -200,11 +201,11 @@ fn check_field_shorthand(acc: &mut Vec<Diagnostic>, file_id: FileId, node: &Synt
 fn check_expr_field_shorthand(
     acc: &mut Vec<Diagnostic>,
     file_id: FileId,
-    record_lit: ast::RecordExpr,
+    record_expr: ast::RecordExpr,
 ) {
-    let record_field_list = match record_lit.record_expr_field_list() {
+    let record_field_list = match record_expr.record_expr_field_list() {
         Some(it) => it,
-        None => (),
+        None => return,
     };
     for record_field in record_field_list.fields() {
         let (name_ref, expr) = match record_field.name_ref().zip(record_field.expr()) {
@@ -239,6 +240,48 @@ fn check_expr_field_shorthand(
     }
 }
 
+fn check_pat_field_shorthand(
+    acc: &mut Vec<Diagnostic>,
+    file_id: FileId,
+    record_pat: ast::RecordPat,
+) {
+    let record_pat_field_list = match record_pat.record_pat_field_list() {
+        Some(it) => it,
+        None => return,
+    };
+    for record_pat_field in record_pat_field_list.fields() {
+        let (name_ref, pat) = match record_pat_field.name_ref().zip(record_pat_field.pat()) {
+            Some(it) => it,
+            None => continue,
+        };
+
+        let field_name = name_ref.syntax().text().to_string();
+        let field_pat = pat.syntax().text().to_string();
+        let field_name_is_tup_index = name_ref.as_tuple_field().is_some();
+        if field_name != field_pat || field_name_is_tup_index {
+            continue;
+        }
+
+        let mut edit_builder = TextEdit::builder();
+        edit_builder.delete(record_pat_field.syntax().text_range());
+        edit_builder.insert(record_pat_field.syntax().text_range().start(), field_name);
+        let edit = edit_builder.finish();
+
+        let field_range = record_pat_field.syntax().text_range();
+        acc.push(Diagnostic {
+            // name: None,
+            range: field_range,
+            message: "Shorthand struct pattern".to_string(),
+            severity: Severity::WeakWarning,
+            fix: Some(Fix::new(
+                "Use struct field shorthand",
+                SourceFileEdit { file_id, edit }.into(),
+                field_range,
+            )),
+        });
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use expect_test::{expect, Expect};
@@ -735,7 +778,7 @@ mod a {
     }
 
     #[test]
-    fn test_check_struct_shorthand_initialization() {
+    fn test_check_expr_field_shorthand() {
         check_no_diagnostics(
             r#"
 struct A { a: &'static str }
@@ -786,6 +829,52 @@ fn main() {
         );
     }
 
+    #[test]
+    fn test_check_pat_field_shorthand() {
+        check_no_diagnostics(
+            r#"
+struct A { a: &'static str }
+fn f(a: A) { let A { a: hello } = a; }
+"#,
+        );
+        check_no_diagnostics(
+            r#"
+struct A(usize);
+fn f(a: A) { let A { 0: 0 } = a; }
+"#,
+        );
+
+        check_fix(
+            r#"
+struct A { a: &'static str }
+fn f(a: A) {
+    let A { a<|>: a } = a;
+}
+"#,
+            r#"
+struct A { a: &'static str }
+fn f(a: A) {
+    let A { a } = a;
+}
+"#,
+        );
+
+        check_fix(
+            r#"
+struct A { a: &'static str, b: &'static str }
+fn f(a: A) {
+    let A { a<|>: a, b } = a;
+}
+"#,
+            r#"
+struct A { a: &'static str, b: &'static str }
+fn f(a: A) {
+    let A { a, b } = a;
+}
+"#,
+        );
+    }
+
     #[test]
     fn test_add_field_from_usage() {
         check_fix(
-- 
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