Auto merge of rust-lang#12075 - jonas-schievink:less-aggressive-quickfixes, r=jonas-schievink

fix: Don't emit a quickfix for placeholder suggestions from rustc/clippy

Fixes rust-lang/rust-analyzer#12069

Author: bors

crates/rust-analyzer/src/diagnostics/test_data/clippy_pass_by_ref.txt

@@ -296,70 +296,6 @@
             tags: None,
             data: None,
         },
-        fix: Some(
-            Fix {
-                ranges: [
-                    Range {
-                        start: Position {
-                            line: 41,
-                            character: 23,
-                        },
-                        end: Position {
-                            line: 41,
-                            character: 28,
-                        },
-                    },
-                ],
-                action: CodeAction {
-                    title: "consider passing by value instead: `self`",
-                    group: None,
-                    kind: Some(
-                        CodeActionKind(
-                            "quickfix",
-                        ),
-                    ),
-                    command: None,
-                    edit: Some(
-                        SnippetWorkspaceEdit {
-                            changes: Some(
-                                {
-                                    Url {
-                                        scheme: "file",
-                                        cannot_be_a_base: false,
-                                        username: "",
-                                        password: None,
-                                        host: None,
-                                        port: None,
-                                        path: "/test/compiler/mir/tagset.rs",
-                                        query: None,
-                                        fragment: None,
-                                    }: [
-                                        TextEdit {
-                                            range: Range {
-                                                start: Position {
-                                                    line: 41,
-                                                    character: 23,
-                                                },
-                                                end: Position {
-                                                    line: 41,
-                                                    character: 28,
-                                                },
-                                            },
-                                            new_text: "self",
-                                        },
-                                    ],
-                                },
-                            ),
-                            document_changes: None,
-                            change_annotations: None,
-                        },
-                    ),
-                    is_preferred: Some(
-                        true,
-                    ),
-                    data: None,
-                },
-            },
-        ),
+        fix: None,
     },
 ]

crates/rust-analyzer/src/diagnostics/to_proto.rs

@@ -2,7 +2,7 @@
 //! `cargo check` json format to the LSP diagnostic format.
 use std::collections::HashMap;
 
-use flycheck::{DiagnosticLevel, DiagnosticSpan};
+use flycheck::{Applicability, DiagnosticLevel, DiagnosticSpan};
 use itertools::Itertools;
 use stdx::format_to;
 use vfs::{AbsPath, AbsPathBuf};
@@ -159,7 +159,17 @@ fn map_rust_child_diagnostic(
             }
             let location = location(config, workspace_root, span);
             let edit = lsp_types::TextEdit::new(location.range, suggested_replacement.clone());
-            edit_map.entry(location.uri).or_default().push(edit);
+
+            // Only actually emit a quickfix if the suggestion is "valid enough".
+            // We accept both "MaybeIncorrect" and "MachineApplicable". "MaybeIncorrect" means that
+            // the suggestion is *complete* (contains no placeholders where code needs to be
+            // inserted), but might not be what the user wants, or might need minor adjustments.
+            if matches!(
+                span.suggestion_applicability,
+                None | Some(Applicability::MaybeIncorrect | Applicability::MachineApplicable)
+            ) {
+                edit_map.entry(location.uri).or_default().push(edit);
+            }
         }
     }