feat(linter): add DiagnosticResult to the Reporters for receiving a sub part result (#8666)

We are currently outputting only for the default-outputter some extra
information:


3be03926e8/apps/oxlint/src/result.rs (L61-L87)

My goal is that all information will be passed to our new
DiagnosticReporter / OutputFormatter.
This will break the output format in the next PR. **Merging this PR is
the OK for me to make this change** ⚠️
The only breaking point:
`"Found {number_of_warnings} warning{} and {number_of_errors} error{}."`
will still be outputted when `max_warnings_exceeded` is true.

Because this is something the `DiagnosticReporter` should do and not the
`OutputFormatter`.

The end goal is:
- no `println!`, our `OutputFormatter` and his `DiagnosticReporter` will
return `Option<String>` and we output it the our `stdout`
- `LintResult` will only handle `ExitCode` result and nothing more
- `stdout` can be changed from outside (for the next part)
- add snapshots with a custom `stdout`

I do not know if all goals can be done easily. Last two parts should be
a bit tricky for me, never did test setups in rust.
But we do never stop to learn ;)

apps/oxlint/src/lint.rs

@@ -208,15 +208,16 @@ impl Runner for LintRunner {
                 lint_service.run(&tx_error);
             }
         });
-        diagnostic_service.run(&mut stdout);
+
+        let diagnostic_result = diagnostic_service.run(&mut stdout);
 
         CliRunResult::LintResult(LintResult {
             duration: now.elapsed(),
             number_of_rules: lint_service.linter().number_of_rules(),
             number_of_files,
-            number_of_warnings: diagnostic_service.warnings_count(),
-            number_of_errors: diagnostic_service.errors_count(),
-            max_warnings_exceeded: diagnostic_service.max_warnings_exceeded(),
+            number_of_warnings: diagnostic_result.warnings_count(),
+            number_of_errors: diagnostic_result.errors_count(),
+            max_warnings_exceeded: diagnostic_result.max_warnings_exceeded(),
             deny_warnings: warning_options.deny_warnings,
             print_summary: matches!(output_options.format, OutputFormat::Default),
         })

apps/oxlint/src/output_formatter/checkstyle.rs

@@ -3,7 +3,7 @@ use std::{borrow::Cow, io::Write};
 use rustc_hash::FxHashMap;
 
 use oxc_diagnostics::{
-    reporter::{DiagnosticReporter, Info},
+    reporter::{DiagnosticReporter, DiagnosticResult, Info},
     Error, Severity,
 };
 
@@ -31,7 +31,7 @@ struct CheckstyleReporter {
 }
 
 impl DiagnosticReporter for CheckstyleReporter {
-    fn finish(&mut self) -> Option<String> {
+    fn finish(&mut self, _: &DiagnosticResult) -> Option<String> {
         Some(format_checkstyle(&self.diagnostics))
     }
 
@@ -123,7 +123,10 @@ fn xml_escape_impl<F: Fn(u8) -> bool>(raw: &str, escape_chars: F) -> Cow<str> {
 
 #[cfg(test)]
 mod test {
-    use oxc_diagnostics::{reporter::DiagnosticReporter, NamedSource, OxcDiagnostic};
+    use oxc_diagnostics::{
+        reporter::{DiagnosticReporter, DiagnosticResult},
+        NamedSource, OxcDiagnostic,
+    };
     use oxc_span::Span;
 
     use super::CheckstyleReporter;
@@ -142,7 +145,7 @@ mod test {
         assert!(first_result.is_none());
 
         // report not gives us all diagnostics at ones
-        let second_result = reporter.finish();
+        let second_result = reporter.finish(&DiagnosticResult::default());
 
         assert!(second_result.is_some());
         assert_eq!(second_result.unwrap(), "<?xml version=\"1.0\" encoding=\"utf-8\"?><checkstyle version=\"4.3\"><file name=\"file://test.ts\"><error line=\"1\" column=\"1\" severity=\"warning\" message=\"error message\" source=\"\" /></file></checkstyle>");

apps/oxlint/src/output_formatter/default.rs

@@ -1,6 +1,9 @@
 use std::io::Write;
 
-use oxc_diagnostics::{reporter::DiagnosticReporter, Error, GraphicalReportHandler};
+use oxc_diagnostics::{
+    reporter::{DiagnosticReporter, DiagnosticResult},
+    Error, GraphicalReportHandler,
+};
 use oxc_linter::table::RuleTable;
 
 use crate::output_formatter::InternalFormatter;
@@ -37,7 +40,7 @@ impl Default for GraphicalReporter {
 }
 
 impl DiagnosticReporter for GraphicalReporter {
-    fn finish(&mut self) -> Option<String> {
+    fn finish(&mut self, _: &DiagnosticResult) -> Option<String> {
         None
     }
 
@@ -62,7 +65,10 @@ mod test {
         InternalFormatter,
     };
     use miette::{GraphicalReportHandler, GraphicalTheme, NamedSource};
-    use oxc_diagnostics::{reporter::DiagnosticReporter, OxcDiagnostic};
+    use oxc_diagnostics::{
+        reporter::{DiagnosticReporter, DiagnosticResult},
+        OxcDiagnostic,
+    };
     use oxc_span::Span;
 
     #[test]
@@ -78,7 +84,7 @@ mod test {
     fn reporter_finish() {
         let mut reporter = GraphicalReporter::default();
 
-        let result = reporter.finish();
+        let result = reporter.finish(&DiagnosticResult::default());
 
         assert!(result.is_none());
     }

apps/oxlint/src/output_formatter/github.rs

@@ -1,7 +1,7 @@
 use std::{borrow::Cow, io::Write};
 
 use oxc_diagnostics::{
-    reporter::{DiagnosticReporter, Info},
+    reporter::{DiagnosticReporter, DiagnosticResult, Info},
     Error, Severity,
 };
 
@@ -25,7 +25,7 @@ impl InternalFormatter for GithubOutputFormatter {
 struct GithubReporter;
 
 impl DiagnosticReporter for GithubReporter {
-    fn finish(&mut self) -> Option<String> {
+    fn finish(&mut self, _: &DiagnosticResult) -> Option<String> {
         None
     }
 
@@ -88,7 +88,10 @@ fn escape_property(value: &str) -> String {
 
 #[cfg(test)]
 mod test {
-    use oxc_diagnostics::{reporter::DiagnosticReporter, NamedSource, OxcDiagnostic};
+    use oxc_diagnostics::{
+        reporter::{DiagnosticReporter, DiagnosticResult},
+        NamedSource, OxcDiagnostic,
+    };
     use oxc_span::Span;
 
     use super::GithubReporter;
@@ -97,7 +100,7 @@ mod test {
     fn reporter_finish() {
         let mut reporter = GithubReporter;
 
-        let result = reporter.finish();
+        let result = reporter.finish(&DiagnosticResult::default());
 
         assert!(result.is_none());
     }

apps/oxlint/src/output_formatter/json.rs

@@ -1,5 +1,6 @@
 use std::io::Write;
 
+use oxc_diagnostics::reporter::DiagnosticResult;
 use oxc_diagnostics::{reporter::DiagnosticReporter, Error};
 use oxc_linter::rules::RULES;
 use oxc_linter::RuleCategory;
@@ -52,7 +53,7 @@ struct JsonReporter {
 impl DiagnosticReporter for JsonReporter {
     // NOTE: this output does not conform to eslint json format yet
     // https://eslint.org/docs/latest/use/formatters/#json
-    fn finish(&mut self) -> Option<String> {
+    fn finish(&mut self, _: &DiagnosticResult) -> Option<String> {
         Some(format_json(&mut self.diagnostics))
     }
 
@@ -80,7 +81,10 @@ fn format_json(diagnostics: &mut Vec<Error>) -> String {
 
 #[cfg(test)]
 mod test {
-    use oxc_diagnostics::{reporter::DiagnosticReporter, NamedSource, OxcDiagnostic};
+    use oxc_diagnostics::{
+        reporter::{DiagnosticReporter, DiagnosticResult},
+        NamedSource, OxcDiagnostic,
+    };
     use oxc_span::Span;
 
     use super::JsonReporter;
@@ -99,7 +103,7 @@ mod test {
         assert!(first_result.is_none());
 
         // report not gives us all diagnostics at ones
-        let second_result = reporter.finish();
+        let second_result = reporter.finish(&DiagnosticResult::default());
 
         assert!(second_result.is_some());
         assert_eq!(

apps/oxlint/src/output_formatter/stylish.rs

@@ -1,7 +1,7 @@
 use std::io::Write;
 
 use oxc_diagnostics::{
-    reporter::{DiagnosticReporter, Info},
+    reporter::{DiagnosticReporter, DiagnosticResult, Info},
     Error, Severity,
 };
 use rustc_hash::FxHashMap;
@@ -27,7 +27,7 @@ struct StylishReporter {
 }
 
 impl DiagnosticReporter for StylishReporter {
-    fn finish(&mut self) -> Option<String> {
+    fn finish(&mut self, _: &DiagnosticResult) -> Option<String> {
         Some(format_stylish(&self.diagnostics))
     }
 
@@ -116,7 +116,7 @@ fn format_stylish(diagnostics: &[Error]) -> String {
 #[cfg(test)]
 mod test {
     use super::*;
-    use oxc_diagnostics::{NamedSource, OxcDiagnostic};
+    use oxc_diagnostics::{reporter::DiagnosticResult, NamedSource, OxcDiagnostic};
     use oxc_span::Span;
 
     #[test]
@@ -134,7 +134,7 @@ mod test {
         reporter.render_error(error);
         reporter.render_error(warning);
 
-        let output = reporter.finish().unwrap();
+        let output = reporter.finish(&DiagnosticResult::default()).unwrap();
 
         assert!(output.contains("error message"), "Output should contain 'error message'");
         assert!(output.contains("warning message"), "Output should contain 'warning message'");

apps/oxlint/src/output_formatter/unix.rs

@@ -1,7 +1,7 @@
 use std::{borrow::Cow, io::Write};
 
 use oxc_diagnostics::{
-    reporter::{DiagnosticReporter, Info},
+    reporter::{DiagnosticReporter, DiagnosticResult, Info},
     Error, Severity,
 };
 
@@ -28,7 +28,7 @@ struct UnixReporter {
 }
 
 impl DiagnosticReporter for UnixReporter {
-    fn finish(&mut self) -> Option<String> {
+    fn finish(&mut self, _: &DiagnosticResult) -> Option<String> {
         let total = self.total;
         if total > 0 {
             return Some(format!("\n{total} problem{}\n", if total > 1 { "s" } else { "" }));
@@ -57,7 +57,10 @@ fn format_unix(diagnostic: &Error) -> String {
 
 #[cfg(test)]
 mod test {
-    use oxc_diagnostics::{reporter::DiagnosticReporter, NamedSource, OxcDiagnostic};
+    use oxc_diagnostics::{
+        reporter::{DiagnosticReporter, DiagnosticResult},
+        NamedSource, OxcDiagnostic,
+    };
     use oxc_span::Span;
 
     use super::UnixReporter;
@@ -66,7 +69,7 @@ mod test {
     fn reporter_finish_empty() {
         let mut reporter = UnixReporter::default();
 
-        let result = reporter.finish();
+        let result = reporter.finish(&DiagnosticResult::default());
 
         assert!(result.is_none());
     }
@@ -80,7 +83,7 @@ mod test {
             .with_source_code(NamedSource::new("file://test.ts", "debugger;"));
 
         let _ = reporter.render_error(error);
-        let result = reporter.finish();
+        let result = reporter.finish(&DiagnosticResult::default());
 
         assert!(result.is_some());
         assert_eq!(result.unwrap(), "\n1 problem\n");

crates/oxc_diagnostics/src/reporter.rs

@@ -45,7 +45,7 @@ pub trait DiagnosticReporter {
     ///
     /// While this method _should_ only ever be called a single time, this is not a guarantee
     /// upheld in Oxc's API. Do not rely on this behavior.
-    fn finish(&mut self) -> Option<String>;
+    fn finish(&mut self, result: &DiagnosticResult) -> Option<String>;
 
     /// Render a diagnostic into this reporter's desired format. For example, a JSONLinesReporter
     /// might return a stringified JSON object on a single line. Returns [`None`] to skip reporting
@@ -55,6 +55,42 @@ pub trait DiagnosticReporter {
     fn render_error(&mut self, error: Error) -> Option<String>;
 }
 
+/// DiagnosticResult will be submitted to the Reporter when the [`DiagnosticService`](crate::service::DiagnosticService)
+/// is finished receiving all files
+#[derive(Default)]
+pub struct DiagnosticResult {
+    /// Total number of warnings received
+    warnings_count: usize,
+
+    /// Total number of errors received
+    errors_count: usize,
+
+    /// Did the threshold for warnings exceeded the max_warnings?
+    /// ToDo: We giving the input from outside, let the owner calculate the result
+    max_warnings_exceeded: bool,
+}
+
+impl DiagnosticResult {
+    pub fn new(warnings_count: usize, errors_count: usize, max_warnings_exceeded: bool) -> Self {
+        Self { warnings_count, errors_count, max_warnings_exceeded }
+    }
+
+    /// Get the number of warning-level diagnostics received.
+    pub fn warnings_count(&self) -> usize {
+        self.warnings_count
+    }
+
+    /// Get the number of error-level diagnostics received.
+    pub fn errors_count(&self) -> usize {
+        self.errors_count
+    }
+
+    /// Did the threshold for warnings exceeded the max_warnings?
+    pub fn max_warnings_exceeded(&self) -> bool {
+        self.max_warnings_exceeded
+    }
+}
+
 pub struct Info {
     pub start: InfoPosition,
     pub end: InfoPosition,

crates/oxc_diagnostics/src/service.rs

@@ -1,11 +1,13 @@
 use std::{
-    cell::Cell,
     io::{ErrorKind, Write},
     path::{Path, PathBuf},
     sync::{mpsc, Arc},
 };
 
-use crate::{reporter::DiagnosticReporter, Error, NamedSource, OxcDiagnostic, Severity};
+use crate::{
+    reporter::{DiagnosticReporter, DiagnosticResult},
+    Error, NamedSource, OxcDiagnostic, Severity,
+};
 
 pub type DiagnosticTuple = (PathBuf, Vec<Error>);
 pub type DiagnosticSender = mpsc::Sender<Option<DiagnosticTuple>>;
@@ -56,12 +58,6 @@ pub struct DiagnosticService {
     /// which can be used to force exit with an error status if there are too many warning-level rule violations in your project
     max_warnings: Option<usize>,
 
-    /// Total number of warnings received
-    warnings_count: Cell<usize>,
-
-    /// Total number of errors received
-    errors_count: Cell<usize>,
-
     sender: DiagnosticSender,
     receiver: DiagnosticReceiver,
 }
@@ -71,16 +67,7 @@ impl DiagnosticService {
     /// provided [`DiagnosticReporter`].
     pub fn new(reporter: Box<dyn DiagnosticReporter>) -> Self {
         let (sender, receiver) = mpsc::channel();
-        Self {
-            reporter,
-            quiet: false,
-            silent: false,
-            max_warnings: None,
-            warnings_count: Cell::new(0),
-            errors_count: Cell::new(0),
-            sender,
-            receiver,
-        }
+        Self { reporter, quiet: false, silent: false, max_warnings: None, sender, receiver }
     }
 
     /// Set to `true` to only report errors and ignore warnings.
@@ -109,7 +96,7 @@ impl DiagnosticService {
     /// are too many warning-level rule violations in your project. Errors do not count towards the
     /// warning limit.
     ///
-    /// Use [`max_warnings_exceeded`](DiagnosticService::max_warnings_exceeded) to check if too
+    /// Use [`DiagnosticResult`](DiagnosticResult::max_warnings_exceeded) to check if too
     /// many warnings have been received.
     ///
     /// Default: [`None`]
@@ -129,20 +116,10 @@ impl DiagnosticService {
         &self.sender
     }
 
-    /// Get the number of warning-level diagnostics received.
-    pub fn warnings_count(&self) -> usize {
-        self.warnings_count.get()
-    }
-
-    /// Get the number of error-level diagnostics received.
-    pub fn errors_count(&self) -> usize {
-        self.errors_count.get()
-    }
-
     /// Check if the max warning threshold, as set by
     /// [`with_max_warnings`](DiagnosticService::with_max_warnings), has been exceeded.
-    pub fn max_warnings_exceeded(&self) -> bool {
-        self.max_warnings.is_some_and(|max_warnings| self.warnings_count.get() > max_warnings)
+    fn max_warnings_exceeded(&self, warnings_count: usize) -> bool {
+        self.max_warnings.is_some_and(|max_warnings| warnings_count > max_warnings)
     }
 
     /// Wrap [diagnostics] with the source code and path, converting them into [Error]s.
@@ -165,7 +142,16 @@ impl DiagnosticService {
     /// # Panics
     ///
     /// * When the writer fails to write
-    pub fn run(&mut self, writer: &mut dyn Write) {
+    ///
+    /// ToDo:
+    /// We are passing [`DiagnosticResult`] to the [`DiagnosticReporter`] already
+    /// currently for the GraphicalReporter there is another extra output,
+    /// which does some more things. This is the reason why we are returning it.
+    /// Let's check at first it we can easily change for the default output before removing this return.
+    pub fn run(&mut self, writer: &mut dyn Write) -> DiagnosticResult {
+        let mut warnings_count: usize = 0;
+        let mut errors_count: usize = 0;
+
         while let Ok(Some((path, diagnostics))) = self.receiver.recv() {
             for diagnostic in diagnostics {
                 let severity = diagnostic.severity();
@@ -173,12 +159,10 @@ impl DiagnosticService {
                 let is_error = severity == Some(Severity::Error) || severity.is_none();
                 if is_warning || is_error {
                     if is_warning {
-                        let warnings_count = self.warnings_count() + 1;
-                        self.warnings_count.set(warnings_count);
+                        warnings_count += 1;
                     }
                     if is_error {
-                        let errors_count = self.errors_count() + 1;
-                        self.errors_count.set(errors_count);
+                        errors_count += 1;
                     }
                     // The --quiet flag follows ESLint's --quiet behavior as documented here: https://eslint.org/docs/latest/use/command-line-interface#--quiet
                     // Note that it does not disable ALL diagnostics, only Warning diagnostics
@@ -217,7 +201,13 @@ impl DiagnosticService {
             }
         }
 
-        if let Some(finish_output) = self.reporter.finish() {
+        let result = DiagnosticResult::new(
+            warnings_count,
+            errors_count,
+            self.max_warnings_exceeded(warnings_count),
+        );
+
+        if let Some(finish_output) = self.reporter.finish(&result) {
             writer
                 .write_all(finish_output.as_bytes())
                 .or_else(Self::check_for_writer_error)
@@ -225,6 +215,8 @@ impl DiagnosticService {
         }
 
         writer.flush().or_else(Self::check_for_writer_error).unwrap();
+
+        result
     }
 
     fn check_for_writer_error(error: std::io::Error) -> Result<(), std::io::Error> {