feat: add config for inserting must_use in generate_enum_as_method

Author: feniljain

crates/ide-assists/src/assist_config.rs

@@ -14,4 +14,5 @@ pub struct AssistConfig {
     pub allowed: Option<Vec<AssistKind>>,
     pub insert_use: InsertUseConfig,
     pub prefer_no_std: bool,
+    pub assist_generate_enum_projection_method_insert_must_use_macro: bool,
 }

crates/ide-assists/src/handlers/generate_enum_projection_method.rs

@@ -150,26 +150,52 @@ fn generate_enum_projection_method(
         target,
         |builder| {
             let vis = parent_enum.visibility().map_or(String::new(), |v| format!("{} ", v));
-            let method = format!(
-                "    {0}fn {1}({2}) -> {3}{4}{5} {{
+
+            let method = if ctx.config.assist_generate_enum_projection_method_insert_must_use_macro
+            {
+                format!(
+                    "    #[must_use]
+    {0}fn {1}({2}) -> {3}{4}{5} {{
+        if let Self::{6}{7} = self {{
+            {8}({9})
+        }} else {{
+            {10}
+        }}
+    }}",
+                    vis,
+                    fn_name,
+                    props.self_param,
+                    props.return_prefix,
+                    field_type.syntax(),
+                    props.return_suffix,
+                    variant_name,
+                    pattern_suffix,
+                    props.happy_case,
+                    bound_name,
+                    props.sad_case,
+                )
+            } else {
+                format!(
+                    "    {0}fn {1}({2}) -> {3}{4}{5} {{
         if let Self::{6}{7} = self {{
             {8}({9})
         }} else {{
             {10}
         }}
     }}",
-                vis,
-                fn_name,
-                props.self_param,
-                props.return_prefix,
-                field_type.syntax(),
-                props.return_suffix,
-                variant_name,
-                pattern_suffix,
-                props.happy_case,
-                bound_name,
-                props.sad_case,
-            );
+                    vis,
+                    fn_name,
+                    props.self_param,
+                    props.return_prefix,
+                    field_type.syntax(),
+                    props.return_suffix,
+                    variant_name,
+                    pattern_suffix,
+                    props.happy_case,
+                    bound_name,
+                    props.sad_case,
+                )
+            };
 
             add_method_to_adt(builder, &parent_enum, impl_def, &method);
         },

crates/ide-assists/src/tests.rs

@@ -30,6 +30,7 @@ pub(crate) const TEST_CONFIG: AssistConfig = AssistConfig {
         skip_glob_imports: true,
     },
     prefer_no_std: false,
+    assist_generate_enum_projection_method_insert_must_use_macro: false,
 };
 
 pub(crate) fn with_single_file(text: &str) -> (RootDatabase, FileId) {

crates/rust-analyzer/src/config.rs

@@ -58,6 +58,9 @@ config_data! {
     struct ConfigData {
         /// Placeholder expression to use for missing expressions in assists.
         assist_expressionFillDefault: ExprFillDefaultDef              = "\"todo\"",
+        /// Whether to insert must_use derive macro while generating `as_` methods
+        /// for enum variants.
+        assist_generateEnumProjectionMethod_insert_must_use_macro: bool               = "false",
 
         /// Warm up caches on project load.
         cachePriming_enable: bool = "true",
@@ -1227,6 +1230,9 @@ impl Config {
             allowed: None,
             insert_use: self.insert_use_config(),
             prefer_no_std: self.data.imports_prefer_no_std,
+            assist_generate_enum_projection_method_insert_must_use_macro: self
+                .data
+                .assist_generateEnumProjectionMethod_insert_must_use_macro,
         }
     }
 

docs/user/generated_config.adoc

@@ -3,6 +3,12 @@
 --
 Placeholder expression to use for missing expressions in assists.
 --
+[[rust-analyzer.assist.generateEnumProjectionMethod.insert.must.use.macro]]rust-analyzer.assist.generateEnumProjectionMethod.insert.must.use.macro (default: `false`)::
++
+--
+Whether to insert must_use derive macro while generating `as_` methods
+for enum variants.
+--
 [[rust-analyzer.cachePriming.enable]]rust-analyzer.cachePriming.enable (default: `true`)::
 +
 --

editors/code/package.json

@@ -399,6 +399,11 @@
                         "Fill missing expressions with reasonable defaults, `new` or `default` constructors."
                     ]
                 },
+                "rust-analyzer.assist.generateEnumProjectionMethod.insert.must.use.macro": {
+                    "markdownDescription": "Whether to insert must_use derive macro while generating `as_` methods\nfor enum variants.",
+                    "default": false,
+                    "type": "boolean"
+                },
                 "rust-analyzer.cachePriming.enable": {
                     "markdownDescription": "Warm up caches on project load.",
                     "default": true,