Merge #167

167: Attempt to extract useful comments from function signatures r=matklad a=kjeremy

I'm trying to extract useful function comments for signature info. This will also be useful for hover.  This is a WIP (and actually works pretty well!) but I don't think it's the right approach long term so some guidance would be appreciated so that we could also get comments for say types and variable instances etc.

Currently `test_fn_signature_with_simple_doc` fails due to a bug in `extend` but we probably shouldn't use this approach anyway. Maybe comments should be attached to nodes somehow? I'm also thinking that maybe the markdown bits should live in the language server.

Thoughts?

Co-authored-by: Jeremy A. Kolb <[email protected]>

1 files changed, 147 insertions, 0 deletions

diff --git a/crates/ra_analysis/tests/tests.rs b/crates/ra_analysis/tests/tests.rs
index 94e025677..9e2478d9e 100644
--- a/crates/ra_analysis/tests/tests.rs
+++ b/crates/ra_analysis/tests/tests.rs
@@ -195,6 +195,153 @@ fn bar() {
     assert_eq!(param, Some(1));
 }
 
+#[test]
+fn test_fn_signature_with_docs_simple() {
+    let (desc, param) = get_signature(
+        r#"
+// test
+fn foo(j: u32) -> u32 {
+    j
+}
+
+fn bar() {
+    let _ = foo(<|>);
+}
+"#,
+    );
+
+    assert_eq!(desc.name, "foo".to_string());
+    assert_eq!(desc.params, vec!["j".to_string()]);
+    assert_eq!(desc.ret_type, Some("-> u32".to_string()));
+    assert_eq!(param, Some(0));
+    assert_eq!(desc.label, "fn foo(j: u32) -> u32".to_string());
+    assert_eq!(desc.doc, Some("test".into()));
+}
+
+#[test]
+fn test_fn_signature_with_docs() {
+    let (desc, param) = get_signature(
+        r#"
+/// Adds one to the number given.
+///
+/// # Examples
+///
+/// ```
+/// let five = 5;
+///
+/// assert_eq!(6, my_crate::add_one(5));
+/// ```
+pub fn add_one(x: i32) -> i32 {
+    x + 1
+}
+
+pub fn do() {
+    add_one(<|>
+}"#,
+    );
+
+    assert_eq!(desc.name, "add_one".to_string());
+    assert_eq!(desc.params, vec!["x".to_string()]);
+    assert_eq!(desc.ret_type, Some("-> i32".to_string()));
+    assert_eq!(param, Some(0));
+    assert_eq!(desc.label, "pub fn add_one(x: i32) -> i32".to_string());
+    assert_eq!(desc.doc, Some(
+r#"Adds one to the number given.
+
+# Examples
+
+```rust
+let five = 5;
+
+assert_eq!(6, my_crate::add_one(5));
+```"#.into()));
+}
+
+#[test]
+fn test_fn_signature_with_docs_impl() {
+    let (desc, param) = get_signature(
+        r#"
+struct addr;
+impl addr {
+    /// Adds one to the number given.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let five = 5;
+    ///
+    /// assert_eq!(6, my_crate::add_one(5));
+    /// ```
+    pub fn add_one(x: i32) -> i32 {
+        x + 1
+    }
+}
+
+pub fn do_it() {
+    addr {};
+    addr::add_one(<|>);
+}"#);
+
+    assert_eq!(desc.name, "add_one".to_string());
+    assert_eq!(desc.params, vec!["x".to_string()]);
+    assert_eq!(desc.ret_type, Some("-> i32".to_string()));
+    assert_eq!(param, Some(0));
+    assert_eq!(desc.label, "pub fn add_one(x: i32) -> i32".to_string());
+    assert_eq!(desc.doc, Some(
+r#"Adds one to the number given.
+
+# Examples
+
+```rust
+let five = 5;
+
+assert_eq!(6, my_crate::add_one(5));
+```"#.into()));
+}
+
+#[test]
+fn test_fn_signature_with_docs_from_actix() {
+    let (desc, param) = get_signature(
+        r#"
+pub trait WriteHandler<E>
+where
+    Self: Actor,
+    Self::Context: ActorContext,
+{
+    /// Method is called when writer emits error.
+    ///
+    /// If this method returns `ErrorAction::Continue` writer processing
+    /// continues otherwise stream processing stops.
+    fn error(&mut self, err: E, ctx: &mut Self::Context) -> Running {
+        Running::Stop
+    }
+
+    /// Method is called when writer finishes.
+    ///
+    /// By default this method stops actor's `Context`.
+    fn finished(&mut self, ctx: &mut Self::Context) {
+        ctx.stop()
+    }
+}
+
+pub fn foo() {
+    WriteHandler r;
+    r.finished(<|>);
+}
+
+"#);
+
+    assert_eq!(desc.name, "finished".to_string());
+    assert_eq!(desc.params, vec!["&mut self".to_string(), "ctx".to_string()]);
+    assert_eq!(desc.ret_type, None);
+    assert_eq!(param, Some(1));
+    assert_eq!(desc.doc, Some(
+r#"Method is called when writer finishes.
+
+By default this method stops actor's `Context`."#.into()));
+}
+
+
 fn get_all_refs(text: &str) -> Vec<(FileId, TextRange)> {
     let (analysis, position) = single_file_with_position(text);
     analysis.find_all_refs(position.file_id, position.offset).unwrap()