Set the diagnostic URL for lint errors (#21514)

Summary
--

This PR wires up the `Diagnostic::set_documentation_url` method from
#21502 to Ruff's lint diagnostics. This enables the links for the full
and concise output formats without any other changes.

I considered also including the URLs for the grouped and pylint output
formats, but the grouped format is still in `ruff_linter` instead of
`ruff_db`, so we'd have to export some additional functionality to wire
it up with `fmt_with_hyperlink`; and the pylint format doesn't currently
render with color, so I think it might actually be machine readable
rather than human readable?

The other ouput formats (json, json-lines, junit, github, gitlab,
rdjson, azure, sarif) seem more clearly not to need the links.

Test Plan
--

I guess you can't see my cursor or the browser opening, but it works for
lint rules, which have links, and doesn't include a link for syntax
errors, which don't have valid links.


![out](https://github.com/user-attachments/assets/a520c7f9-6d7b-4e5f-a1a9-3c5e21a51d3c)

crates/ruff_db/src/diagnostic/mod.rs

@@ -452,28 +452,6 @@ impl Diagnostic {
             .map(|sub| sub.inner.message.as_str())
     }
 
-    /// Returns the URL for the rule documentation, if it exists.
-    pub fn to_ruff_url(&self) -> Option<String> {
-        match self.id() {
-            DiagnosticId::Panic
-            | DiagnosticId::Io
-            | DiagnosticId::InvalidSyntax
-            | DiagnosticId::RevealedType
-            | DiagnosticId::UnknownRule
-            | DiagnosticId::InvalidGlob
-            | DiagnosticId::EmptyInclude
-            | DiagnosticId::UnnecessaryOverridesSection
-            | DiagnosticId::UselessOverridesSection
-            | DiagnosticId::DeprecatedSetting
-            | DiagnosticId::Unformatted
-            | DiagnosticId::InvalidCliOption
-            | DiagnosticId::InternalError => None,
-            DiagnosticId::Lint(lint_name) => {
-                Some(format!("{}/rules/{lint_name}", env!("CARGO_PKG_HOMEPAGE")))
-            }
-        }
-    }
-
     /// Returns the filename for the message.
     ///
     /// Panics if the diagnostic has no primary span, or if its file is not a `SourceFile`.

crates/ruff_db/src/diagnostic/render.rs

@@ -2881,6 +2881,12 @@ watermelon
             self.diag.help(message);
             self
         }
+
+        /// Set the documentation URL for the diagnostic.
+        pub(super) fn documentation_url(mut self, url: impl Into<String>) -> DiagnosticBuilder<'e> {
+            self.diag.set_documentation_url(Some(url.into()));
+            self
+        }
     }
 
     /// A helper builder for tersely populating a `SubDiagnostic`.
@@ -2995,6 +3001,7 @@ def fibonacci(n):
                     TextSize::from(10),
                 ))))
                 .noqa_offset(TextSize::from(7))
+                .documentation_url("https://docs.astral.sh/ruff/rules/unused-import")
                 .build(),
             env.builder(
                 "unused-variable",
@@ -3009,11 +3016,13 @@ def fibonacci(n):
                 TextSize::from(99),
             )))
             .noqa_offset(TextSize::from(94))
+            .documentation_url("https://docs.astral.sh/ruff/rules/unused-variable")
             .build(),
             env.builder("undefined-name", Severity::Error, "Undefined name `a`")
                 .primary("undef.py", "1:3", "1:4", "")
                 .secondary_code("F821")
                 .noqa_offset(TextSize::from(3))
+                .documentation_url("https://docs.astral.sh/ruff/rules/undefined-name")
                 .build(),
         ];
 
@@ -3128,6 +3137,7 @@ if call(foo
                     TextSize::from(19),
                 ))))
                 .noqa_offset(TextSize::from(16))
+                .documentation_url("https://docs.astral.sh/ruff/rules/unused-import")
                 .build(),
             env.builder(
                 "unused-import",
@@ -3142,6 +3152,7 @@ if call(foo
                 TextSize::from(40),
             ))))
             .noqa_offset(TextSize::from(35))
+            .documentation_url("https://docs.astral.sh/ruff/rules/unused-import")
             .build(),
             env.builder(
                 "unused-variable",
@@ -3156,6 +3167,7 @@ if call(foo
                 TextSize::from(104),
             ))))
             .noqa_offset(TextSize::from(98))
+            .documentation_url("https://docs.astral.sh/ruff/rules/unused-variable")
             .build(),
         ];
 

crates/ruff_db/src/diagnostic/render/json.rs

@@ -100,7 +100,7 @@ pub(super) fn diagnostic_to_json<'a>(
     if config.preview {
         JsonDiagnostic {
             code: diagnostic.secondary_code_or_id(),
-            url: diagnostic.to_ruff_url(),
+            url: diagnostic.documentation_url(),
             message: diagnostic.body(),
             fix,
             cell: notebook_cell_index,
@@ -112,7 +112,7 @@ pub(super) fn diagnostic_to_json<'a>(
     } else {
         JsonDiagnostic {
             code: diagnostic.secondary_code_or_id(),
-            url: diagnostic.to_ruff_url(),
+            url: diagnostic.documentation_url(),
             message: diagnostic.body(),
             fix,
             cell: notebook_cell_index,
@@ -228,7 +228,7 @@ pub(crate) struct JsonDiagnostic<'a> {
     location: Option<JsonLocation>,
     message: &'a str,
     noqa_row: Option<OneIndexed>,
-    url: Option<String>,
+    url: Option<&'a str>,
 }
 
 #[derive(Serialize)]
@@ -294,7 +294,10 @@ mod tests {
         env.format(DiagnosticFormat::Json);
         env.preview(false);
 
-        let diag = env.err().build();
+        let diag = env
+            .err()
+            .documentation_url("https://docs.astral.sh/ruff/rules/test-diagnostic")
+            .build();
 
         insta::assert_snapshot!(
             env.render(&diag),
@@ -328,7 +331,10 @@ mod tests {
         env.format(DiagnosticFormat::Json);
         env.preview(true);
 
-        let diag = env.err().build();
+        let diag = env
+            .err()
+            .documentation_url("https://docs.astral.sh/ruff/rules/test-diagnostic")
+            .build();
 
         insta::assert_snapshot!(
             env.render(&diag),

crates/ruff_db/src/diagnostic/render/rdjson.rs

@@ -82,7 +82,7 @@ fn diagnostic_to_rdjson<'a>(
             value: diagnostic
                 .secondary_code()
                 .map_or_else(|| diagnostic.name(), |code| code.as_str()),
-            url: diagnostic.to_ruff_url(),
+            url: diagnostic.documentation_url(),
         },
         suggestions: rdjson_suggestions(
             edits,
@@ -182,7 +182,7 @@ impl RdjsonRange {
 #[derive(Serialize)]
 struct RdjsonCode<'a> {
     #[serde(skip_serializing_if = "Option::is_none")]
-    url: Option<String>,
+    url: Option<&'a str>,
     value: &'a str,
 }
 
@@ -217,7 +217,10 @@ mod tests {
         env.format(DiagnosticFormat::Rdjson);
         env.preview(false);
 
-        let diag = env.err().build();
+        let diag = env
+            .err()
+            .documentation_url("https://docs.astral.sh/ruff/rules/test-diagnostic")
+            .build();
 
         insta::assert_snapshot!(env.render(&diag));
     }
@@ -228,7 +231,10 @@ mod tests {
         env.format(DiagnosticFormat::Rdjson);
         env.preview(true);
 
-        let diag = env.err().build();
+        let diag = env
+            .err()
+            .documentation_url("https://docs.astral.sh/ruff/rules/test-diagnostic")
+            .build();
 
         insta::assert_snapshot!(env.render(&diag));
     }

crates/ruff_linter/src/message/mod.rs

@@ -125,6 +125,7 @@ where
     }
 
     diagnostic.set_secondary_code(SecondaryCode::new(rule.noqa_code().to_string()));
+    diagnostic.set_documentation_url(rule.url());
 
     diagnostic
 }

crates/ruff_server/src/lint.rs

@@ -301,9 +301,9 @@ fn to_lsp_diagnostic(
             severity,
             tags,
             code,
-            code_description: diagnostic.to_ruff_url().and_then(|url| {
+            code_description: diagnostic.documentation_url().and_then(|url| {
                 Some(lsp_types::CodeDescription {
-                    href: lsp_types::Url::parse(&url).ok()?,
+                    href: lsp_types::Url::parse(url).ok()?,
                 })
             }),
             source: Some(DIAGNOSTIC_NAME.into()),