feat: inlay hints on try-expr

crates/ide/src/inlay_hints.rs

@@ -44,6 +44,7 @@ mod param_name;
 mod placeholders;
 mod ra_fixture;
 mod range_exclusive;
+mod try_expr;
 
 // Feature: Inlay Hints
 //
@@ -252,6 +253,7 @@ fn hints(
                         file_id.edition(sema.db),
                     ),
                     ast::Expr::RangeExpr(it) => range_exclusive::hints(hints, famous_defs, config, it),
+                    ast::Expr::TryExpr(it) => try_expr::hints(hints, famous_defs, config, it),
                     ast::Expr::Literal(it) => ra_fixture::hints(hints, famous_defs.0, file_id, config, it),
                     _ => Some(()),
                 }
@@ -339,6 +341,7 @@ pub struct InlayHintsConfig<'a> {
     pub hide_closure_initialization_hints: bool,
     pub hide_closure_parameter_hints: bool,
     pub range_exclusive_hints: bool,
+    pub try_expr_hints: bool,
     pub closure_style: ClosureStyle,
     pub max_length: Option<usize>,
     pub closing_brace_hints_min_lines: Option<usize>,
@@ -966,6 +969,7 @@ mod tests {
         implicit_drop_hints: false,
         implied_dyn_trait_hints: false,
         range_exclusive_hints: false,
+        try_expr_hints: false,
         ra_fixture: RaFixtureConfig::default(),
     };
     pub(super) const TEST_CONFIG: InlayHintsConfig<'_> = InlayHintsConfig {

crates/ide/src/inlay_hints/try_expr.rs

@@ -0,0 +1,62 @@
+//! Implementation of "try expr" inlay hints:
+//! ```ignore
+//! val.foo()/* .try */?.bar()/* .try */?
+//! ```
+//! This can avoid try-expr not being obvious enough
+use ide_db::famous_defs::FamousDefs;
+use syntax::{SyntaxToken, ast};
+
+use crate::{InlayHint, InlayHintsConfig};
+
+pub(super) fn hints(
+    acc: &mut Vec<InlayHint>,
+    FamousDefs(_sema, _): &FamousDefs<'_, '_>,
+    config: &InlayHintsConfig<'_>,
+    expr: ast::TryExpr,
+) -> Option<()> {
+    config
+        .try_expr_hints
+        .then(|| {
+            expr.question_mark_token().map(|token| {
+                acc.push(inlay_hint(token));
+            })
+        })
+        .flatten()
+}
+
+fn inlay_hint(token: SyntaxToken) -> InlayHint {
+    InlayHint {
+        range: token.text_range(),
+        position: crate::InlayHintPosition::Before,
+        pad_left: false,
+        pad_right: false,
+        kind: crate::InlayKind::RangeExclusive,
+        label: crate::InlayHintLabel::from(".try"),
+        text_edit: None,
+        resolve_parent: None,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::{
+        InlayHintsConfig,
+        inlay_hints::tests::{DISABLED_CONFIG, check_with_config},
+    };
+
+    #[test]
+    fn basic_works() {
+        check_with_config(
+            InlayHintsConfig { try_expr_hints: true, ..DISABLED_CONFIG },
+            r#"
+fn main() {
+    foo.x()?
+         //^ .try
+        .bar()?
+            //^ .try
+        .await?;
+            //^ .try
+}"#,
+        );
+    }
+}

crates/rust-analyzer/src/cli/analysis_stats.rs

@@ -1416,6 +1416,7 @@ impl flags::AnalysisStats {
                     closing_brace_hints_min_lines: Some(20),
                     fields_to_resolve: InlayFieldsToResolve::empty(),
                     range_exclusive_hints: true,
+                    try_expr_hints: true,
                     ra_fixture: RaFixtureConfig::default(),
                 },
                 analysis.editioned_file_id_to_vfs(file_id),

crates/rust-analyzer/src/config.rs

@@ -296,6 +296,9 @@ config_data! {
         /// Whether to render leading colons for type hints, and trailing colons for parameter hints.
         inlayHints_renderColons: bool = true,
 
+        /// Show try-expr inlay hints (e.g `foo()?;` -> `foo().try?;`).
+        inlayHints_tryExpressionHints_enable: bool = false,
+
         /// Show inlay type hints for variables.
         inlayHints_typeHints_enable: bool = true,
 
@@ -2173,6 +2176,7 @@ impl Config {
             implicit_drop_hints: self.inlayHints_implicitDrops_enable().to_owned(),
             implied_dyn_trait_hints: self.inlayHints_impliedDynTraitHints_enable().to_owned(),
             range_exclusive_hints: self.inlayHints_rangeExclusiveHints_enable().to_owned(),
+            try_expr_hints: self.inlayHints_tryExpressionHints_enable().to_owned(),
             ra_fixture: self.ra_fixture(minicore),
         }
     }

docs/book/src/configuration_generated.md

@@ -1150,6 +1150,13 @@ Default: `true`
 Whether to render leading colons for type hints, and trailing colons for parameter hints.
 
 
+## rust-analyzer.inlayHints.tryExpressionHints.enable {#inlayHints.tryExpressionHints.enable}
+
+Default: `false`
+
+Show try-expr inlay hints (e.g `foo()?;` -> `foo().try?;`).
+
+
 ## rust-analyzer.inlayHints.typeHints.enable {#inlayHints.typeHints.enable}
 
 Default: `true`

editors/code/package.json

@@ -2531,6 +2531,16 @@
                     }
                 }
             },
+            {
+                "title": "Inlay Hints",
+                "properties": {
+                    "rust-analyzer.inlayHints.tryExpressionHints.enable": {
+                        "markdownDescription": "Show try-expr inlay hints (e.g `foo()?;` -> `foo().try?;`).",
+                        "default": false,
+                        "type": "boolean"
+                    }
+                }
+            },
             {
                 "title": "Inlay Hints",
                 "properties": {