feat(lsp): show hints from deno_lint in addition to messages (#10739)

cli/lsp/analysis.rs

@@ -60,6 +60,7 @@ lazy_static::lazy_static! {
 
 /// Category of self-generated diagnostic messages (those not coming from)
 /// TypeScript.
+#[derive(Debug, PartialEq, Eq)]
 pub enum Category {
   /// A lint diagnostic, where the first element is the message.
   Lint {
@@ -70,6 +71,7 @@ pub enum Category {
 }
 
 /// A structure to hold a reference to a diagnostic message.
+#[derive(Debug, PartialEq, Eq)]
 pub struct Reference {
   category: Category,
   range: Range,
@@ -78,13 +80,24 @@ pub struct Reference {
 impl Reference {
   pub fn to_diagnostic(&self) -> lsp::Diagnostic {
     match &self.category {
-      Category::Lint { message, code, .. } => lsp::Diagnostic {
+      Category::Lint {
+        message,
+        code,
+        hint,
+      } => lsp::Diagnostic {
         range: self.range,
         severity: Some(lsp::DiagnosticSeverity::Warning),
         code: Some(lsp::NumberOrString::String(code.to_string())),
         code_description: None,
         source: Some("deno-lint".to_string()),
-        message: message.to_string(),
+        message: {
+          let mut msg = message.to_string();
+          if let Some(hint) = hint {
+            msg.push('\n');
+            msg.push_str(hint);
+          }
+          msg
+        },
         related_information: None,
         tags: None, // we should tag unused code
         data: None,
@@ -702,6 +715,64 @@ mod tests {
   use super::*;
   use deno_core::resolve_url;
 
+  #[test]
+  fn test_reference_to_diagnostic() {
+    let range = Range {
+      start: Position {
+        line: 1,
+        character: 1,
+      },
+      end: Position {
+        line: 2,
+        character: 2,
+      },
+    };
+
+    let test_cases = [
+      (
+        Reference {
+          category: Category::Lint {
+            message: "message1".to_string(),
+            code: "code1".to_string(),
+            hint: None,
+          },
+          range,
+        },
+        lsp::Diagnostic {
+          range,
+          severity: Some(lsp::DiagnosticSeverity::Warning),
+          code: Some(lsp::NumberOrString::String("code1".to_string())),
+          source: Some("deno-lint".to_string()),
+          message: "message1".to_string(),
+          ..Default::default()
+        },
+      ),
+      (
+        Reference {
+          category: Category::Lint {
+            message: "message2".to_string(),
+            code: "code2".to_string(),
+            hint: Some("hint2".to_string()),
+          },
+          range,
+        },
+        lsp::Diagnostic {
+          range,
+          severity: Some(lsp::DiagnosticSeverity::Warning),
+          code: Some(lsp::NumberOrString::String("code2".to_string())),
+          source: Some("deno-lint".to_string()),
+          message: "message2\nhint2".to_string(),
+          ..Default::default()
+        },
+      ),
+    ];
+
+    for (input, expected) in test_cases.iter() {
+      let actual = input.to_diagnostic();
+      assert_eq!(&actual, expected);
+    }
+  }
+
   #[test]
   fn test_as_lsp_range() {
     let fixture = deno_lint::diagnostic::Range {
@@ -732,6 +803,38 @@ mod tests {
     );
   }
 
+  #[test]
+  fn test_get_lint_references() {
+    let specifier = resolve_url("file:///a.ts").expect("bad specifier");
+    let source = "const foo = 42;";
+    let actual =
+      get_lint_references(&specifier, &MediaType::TypeScript, source).unwrap();
+
+    assert_eq!(
+      actual,
+      vec![Reference {
+        category: Category::Lint {
+          message: "`foo` is never used".to_string(),
+          code: "no-unused-vars".to_string(),
+          hint: Some(
+            "If this is intentional, prefix it with an underscore like `_foo`"
+              .to_string()
+          ),
+        },
+        range: Range {
+          start: Position {
+            line: 0,
+            character: 6,
+          },
+          end: Position {
+            line: 0,
+            character: 9,
+          }
+        }
+      }]
+    );
+  }
+
   #[test]
   fn test_analyze_dependencies() {
     let specifier = resolve_url("file:///a.ts").expect("bad specifier");