Move RDJSON rendering to ruff_db (#19293)

## Summary

Another output format like #19133. This is the
[reviewdog](https://github.com/reviewdog/reviewdog) output format, which
is somewhat similar to regular JSON. Like #19270, in the first commit I
converted from using `json!` to `Serialize` structs, then in the second
commit I moved the module to `ruff_db`.

The reviewdog
[schema](https://github.com/reviewdog/reviewdog/blob/320a8e73a94a09248044314d8ca326a6cd710692/proto/rdf/jsonschema/DiagnosticResult.json)
seems a bit more flexible than our JSON schema, so I'm not sure if we
need any preview checks here. I'll flag the places I wasn't sure about
as review comments.

## Test Plan

New tests in `rdjson.rs`, ported from the old `rjdson.rs` module, as
well as the new CLI output tests.

---------

Co-authored-by: Micha Reiser <micha@reiser.io>

Author: ntBre

crates/ruff/src/printer.rs

@@ -16,7 +16,7 @@ use ruff_linter::fs::relativize_path;
 use ruff_linter::logging::LogLevel;
 use ruff_linter::message::{
     Emitter, EmitterContext, GithubEmitter, GitlabEmitter, GroupedEmitter, JunitEmitter,
-    PylintEmitter, RdjsonEmitter, SarifEmitter, TextEmitter,
+    PylintEmitter, SarifEmitter, TextEmitter,
 };
 use ruff_linter::notify_user;
 use ruff_linter::settings::flags::{self};
@@ -238,7 +238,11 @@ impl Printer {
                 write!(writer, "{value}")?;
             }
             OutputFormat::Rdjson => {
-                RdjsonEmitter.emit(writer, &diagnostics.inner, &context)?;
+                let config = DisplayDiagnosticConfig::default()
+                    .format(DiagnosticFormat::Rdjson)
+                    .preview(preview);
+                let value = DisplayDiagnostics::new(&context, &config, &diagnostics.inner);
+                write!(writer, "{value}")?;
             }
             OutputFormat::JsonLines => {
                 let config = DisplayDiagnosticConfig::default()

crates/ruff/tests/snapshots/lint__output_format_rdjson.snap

@@ -75,8 +75,7 @@ exit_code: 1
     },
     {
       "code": {
-        "url": null,
-        "value": null
+        "value": "invalid-syntax"
       },
       "location": {
         "path": "[TMP]/input.py",
@@ -94,7 +93,7 @@ exit_code: 1
       "message": "SyntaxError: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)"
     }
   ],
-  "severity": "warning",
+  "severity": "WARNING",
   "source": {
     "name": "ruff",
     "url": "https://docs.astral.sh/ruff"

crates/ruff_db/src/diagnostic/mod.rs

@@ -308,6 +308,10 @@ impl Diagnostic {
 
     /// Set the fix for this diagnostic.
     pub fn set_fix(&mut self, fix: Fix) {
+        debug_assert!(
+            self.primary_span().is_some(),
+            "Expected a source file for a diagnostic with a fix"
+        );
         Arc::make_mut(&mut self.inner).fix = Some(fix);
     }
 
@@ -1259,6 +1263,11 @@ pub enum DiagnosticFormat {
     /// format for an array of all diagnostics. See <https://jsonlines.org/> for more details.
     #[cfg(feature = "serde")]
     JsonLines,
+    /// Print diagnostics in the JSON format expected by [reviewdog].
+    ///
+    /// [reviewdog]: https://github.com/reviewdog/reviewdog
+    #[cfg(feature = "serde")]
+    Rdjson,
 }
 
 /// A representation of the kinds of messages inside a diagnostic.

crates/ruff_db/src/diagnostic/render.rs

@@ -28,6 +28,8 @@ mod azure;
 mod json;
 #[cfg(feature = "serde")]
 mod json_lines;
+#[cfg(feature = "serde")]
+mod rdjson;
 
 /// A type that implements `std::fmt::Display` for diagnostic rendering.
 ///
@@ -184,6 +186,10 @@ impl std::fmt::Display for DisplayDiagnostics<'_> {
                 json_lines::JsonLinesRenderer::new(self.resolver, self.config)
                     .render(f, self.diagnostics)?;
             }
+            #[cfg(feature = "serde")]
+            DiagnosticFormat::Rdjson => {
+                rdjson::RdjsonRenderer::new(self.resolver).render(f, self.diagnostics)?;
+            }
         }
 
         Ok(())

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

@@ -262,9 +262,6 @@ struct JsonEdit<'a> {
 
 #[cfg(test)]
 mod tests {
-    use ruff_diagnostics::{Edit, Fix};
-    use ruff_text_size::TextSize;
-
     use crate::diagnostic::{
         DiagnosticFormat,
         render::tests::{
@@ -297,13 +294,7 @@ mod tests {
         env.format(DiagnosticFormat::Json);
         env.preview(false);
 
-        let diag = env
-            .err()
-            .fix(Fix::safe_edit(Edit::insertion(
-                "edit".to_string(),
-                TextSize::from(0),
-            )))
-            .build();
+        let diag = env.err().build();
 
         insta::assert_snapshot!(
             env.render(&diag),
@@ -317,23 +308,7 @@ mod tests {
               "row": 1
             },
             "filename": "",
-            "fix": {
-              "applicability": "safe",
-              "edits": [
-                {
-                  "content": "edit",
-                  "end_location": {
-                    "column": 1,
-                    "row": 1
-                  },
-                  "location": {
-                    "column": 1,
-                    "row": 1
-                  }
-                }
-              ],
-              "message": null
-            },
+            "fix": null,
             "location": {
               "column": 1,
               "row": 1
@@ -353,13 +328,7 @@ mod tests {
         env.format(DiagnosticFormat::Json);
         env.preview(true);
 
-        let diag = env
-            .err()
-            .fix(Fix::safe_edit(Edit::insertion(
-                "edit".to_string(),
-                TextSize::from(0),
-            )))
-            .build();
+        let diag = env.err().build();
 
         insta::assert_snapshot!(
             env.render(&diag),
@@ -370,17 +339,7 @@ mod tests {
             "code": null,
             "end_location": null,
             "filename": null,
-            "fix": {
-              "applicability": "safe",
-              "edits": [
-                {
-                  "content": "edit",
-                  "end_location": null,
-                  "location": null
-                }
-              ],
-              "message": null
-            },
+            "fix": null,
             "location": null,
             "message": "main diagnostic message",
             "noqa_row": null,