Standardize syntax error construction (#20903)

Summary
--

This PR unifies the two different ways Ruff and ty construct syntax
errors. Ruff has been storing the primary message in the diagnostic
itself, while ty attached the message to the primary annotation:

```
> ruff check try.py
invalid-syntax: name capture `x` makes remaining patterns unreachable
 --> try.py:2:10
  |
1 | match 42:
2 |     case x: ...
  |          ^
3 |     case y: ...
  |

Found 1 error.
> uvx ty check try.py
WARN ty is pre-release software and not ready for production use. Expect to encounter bugs, missing features, and fatal errors.
Checking ------------------------------------------------------------ 1/1 files                                                                                                 
error[invalid-syntax]
 --> try.py:2:10
  |
1 | match 42:
2 |     case x: ...
  |          ^ name capture `x` makes remaining patterns unreachable
3 |     case y: ...
  |

Found 1 diagnostic
```

I think there are benefits to both approaches, and I do like ty's
version, but I feel like we should pick one (and it might help with
#20901 eventually). I slightly prefer Ruff's version, so I went with
that. Hopefully this isn't too controversial, but I'm happy to close
this if it is.

Note that this shouldn't change any other diagnostic formats in ty
because
[`Diagnostic::primary_message`](https://github.com/astral-sh/ruff/blob/98d27c412810e157f8a65ea75726d66676628225/crates/ruff_db/src/diagnostic/mod.rs#L177)
was already falling back to the primary annotation message if the
diagnostic message was empty. As a result, I think this change will
partially resolve the FIXME therein.

Test Plan
--

Existing tests with updated snapshots

Author: ntBre

crates/ruff/src/diagnostics.rs

@@ -13,7 +13,6 @@ use log::{debug, warn};
 use ruff_db::diagnostic::Diagnostic;
 use ruff_linter::codes::Rule;
 use ruff_linter::linter::{FixTable, FixerResult, LinterResult, ParseSource, lint_fix, lint_only};
-use ruff_linter::message::create_syntax_error_diagnostic;
 use ruff_linter::package::PackageRoot;
 use ruff_linter::pyproject_toml::lint_pyproject_toml;
 use ruff_linter::settings::types::UnsafeFixes;
@@ -103,11 +102,7 @@ impl Diagnostics {
                 let name = path.map_or_else(|| "-".into(), Path::to_string_lossy);
                 let dummy = SourceFileBuilder::new(name, "").finish();
                 Self::new(
-                    vec![create_syntax_error_diagnostic(
-                        dummy,
-                        err,
-                        TextRange::default(),
-                    )],
+                    vec![Diagnostic::invalid_syntax(dummy, err, TextRange::default())],
                     FxHashMap::default(),
                 )
             }

crates/ruff_db/src/diagnostic/mod.rs

@@ -84,17 +84,14 @@ impl Diagnostic {
     /// at time of writing, `ruff_db` depends on `ruff_python_parser` instead of
     /// the other way around. And since we want to do this conversion in a couple
     /// places, it makes sense to centralize it _somewhere_. So it's here for now.
-    ///
-    /// Note that `message` is stored in the primary annotation, _not_ in the primary diagnostic
-    /// message.
     pub fn invalid_syntax(
         span: impl Into<Span>,
         message: impl IntoDiagnosticMessage,
         range: impl Ranged,
     ) -> Diagnostic {
-        let mut diag = Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, "");
+        let mut diag = Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, message);
         let span = span.into().with_range(range.range());
-        diag.annotate(Annotation::primary(span).message(message));
+        diag.annotate(Annotation::primary(span));
         diag
     }
 

crates/ruff_linter/src/linter.rs

@@ -24,7 +24,6 @@ use crate::checkers::tokens::check_tokens;
 use crate::directives::Directives;
 use crate::doc_lines::{doc_lines_from_ast, doc_lines_from_tokens};
 use crate::fix::{FixResult, fix_file};
-use crate::message::create_syntax_error_diagnostic;
 use crate::noqa::add_noqa;
 use crate::package::PackageRoot;
 use crate::registry::Rule;
@@ -496,15 +495,15 @@ fn diagnostics_to_messages(
     parse_errors
         .iter()
         .map(|parse_error| {
-            create_syntax_error_diagnostic(source_file.clone(), &parse_error.error, parse_error)
+            Diagnostic::invalid_syntax(source_file.clone(), &parse_error.error, parse_error)
         })
         .chain(unsupported_syntax_errors.iter().map(|syntax_error| {
-            create_syntax_error_diagnostic(source_file.clone(), syntax_error, syntax_error)
+            Diagnostic::invalid_syntax(source_file.clone(), syntax_error, syntax_error)
         }))
         .chain(
             semantic_syntax_errors
                 .iter()
-                .map(|error| create_syntax_error_diagnostic(source_file.clone(), error, error)),
+                .map(|error| Diagnostic::invalid_syntax(source_file.clone(), error, error)),
         )
         .chain(diagnostics.into_iter().map(|mut diagnostic| {
             if let Some(range) = diagnostic.range() {

crates/ruff_linter/src/message/mod.rs

@@ -16,7 +16,7 @@ use ruff_db::files::File;
 pub use grouped::GroupedEmitter;
 use ruff_notebook::NotebookIndex;
 use ruff_source_file::{SourceFile, SourceFileBuilder};
-use ruff_text_size::{Ranged, TextRange, TextSize};
+use ruff_text_size::{TextRange, TextSize};
 pub use sarif::SarifEmitter;
 
 use crate::Fix;
@@ -26,24 +26,6 @@ use crate::settings::types::{OutputFormat, RuffOutputFormat};
 mod grouped;
 mod sarif;
 
-/// Creates a `Diagnostic` from a syntax error, with the format expected by Ruff.
-///
-/// This is almost identical to `ruff_db::diagnostic::create_syntax_error_diagnostic`, except the
-/// `message` is stored as the primary diagnostic message instead of on the primary annotation.
-///
-/// TODO(brent) These should be unified at some point, but we keep them separate for now to avoid a
-/// ton of snapshot changes while combining ruff's diagnostic type with `Diagnostic`.
-pub fn create_syntax_error_diagnostic(
-    span: impl Into<Span>,
-    message: impl std::fmt::Display,
-    range: impl Ranged,
-) -> Diagnostic {
-    let mut diag = Diagnostic::new(DiagnosticId::InvalidSyntax, Severity::Error, message);
-    let span = span.into().with_range(range.range());
-    diag.annotate(Annotation::primary(span));
-    diag
-}
-
 /// Create a `Diagnostic` from a panic.
 pub fn create_panic_diagnostic(error: &PanicError, path: Option<&Path>) -> Diagnostic {
     let mut diagnostic = Diagnostic::new(
@@ -260,8 +242,6 @@ mod tests {
     use crate::message::{Emitter, EmitterContext, create_lint_diagnostic};
     use crate::{Edit, Fix};
 
-    use super::create_syntax_error_diagnostic;
-
     pub(super) fn create_syntax_error_diagnostics() -> Vec<Diagnostic> {
         let source = r"from os import
 
@@ -274,7 +254,7 @@ if call(foo
             .errors()
             .iter()
             .map(|parse_error| {
-                create_syntax_error_diagnostic(source_file.clone(), &parse_error.error, parse_error)
+                Diagnostic::invalid_syntax(source_file.clone(), &parse_error.error, parse_error)
             })
             .collect()
     }

crates/ruff_linter/src/test.rs

@@ -26,7 +26,7 @@ use ruff_source_file::SourceFileBuilder;
 use crate::codes::Rule;
 use crate::fix::{FixResult, fix_file};
 use crate::linter::check_path;
-use crate::message::{EmitterContext, create_syntax_error_diagnostic};
+use crate::message::EmitterContext;
 use crate::package::PackageRoot;
 use crate::packaging::detect_package_root;
 use crate::settings::types::UnsafeFixes;
@@ -405,7 +405,7 @@ Either ensure you always emit a fix or change `Violation::FIX_AVAILABILITY` to e
             diagnostic
         })
         .chain(parsed.errors().iter().map(|parse_error| {
-            create_syntax_error_diagnostic(source_code.clone(), &parse_error.error, parse_error)
+            Diagnostic::invalid_syntax(source_code.clone(), &parse_error.error, parse_error)
         }))
         .sorted_by(Diagnostic::ruff_start_ordering)
         .collect();
@@ -419,7 +419,7 @@ fn print_syntax_errors(errors: &[ParseError], path: &Path, source: &SourceKind)
     let messages: Vec<_> = errors
         .iter()
         .map(|parse_error| {
-            create_syntax_error_diagnostic(source_file.clone(), &parse_error.error, parse_error)
+            Diagnostic::invalid_syntax(source_file.clone(), &parse_error.error, parse_error)
         })
         .collect();
 

crates/ty/tests/cli/main.rs

@@ -92,42 +92,42 @@ fn test_quiet_output() -> anyhow::Result<()> {
 #[test]
 fn test_run_in_sub_directory() -> anyhow::Result<()> {
     let case = CliTest::with_files([("test.py", "~"), ("subdir/nothing", "")])?;
-    assert_cmd_snapshot!(case.command().current_dir(case.root().join("subdir")).arg(".."), @r###"
+    assert_cmd_snapshot!(case.command().current_dir(case.root().join("subdir")).arg(".."), @r"
     success: false
     exit_code: 1
     ----- stdout -----
-    error[invalid-syntax]
+    error[invalid-syntax]: Expected an expression
      --> <temp_dir>/test.py:1:2
       |
     1 | ~
-      |  ^ Expected an expression
+      |  ^
       |
 
     Found 1 diagnostic
 
     ----- stderr -----
-    "###);
+    ");
     Ok(())
 }
 
 #[test]
 fn test_include_hidden_files_by_default() -> anyhow::Result<()> {
     let case = CliTest::with_files([(".test.py", "~")])?;
-    assert_cmd_snapshot!(case.command(), @r###"
+    assert_cmd_snapshot!(case.command(), @r"
     success: false
     exit_code: 1
     ----- stdout -----
-    error[invalid-syntax]
+    error[invalid-syntax]: Expected an expression
      --> .test.py:1:2
       |
     1 | ~
-      |  ^ Expected an expression
+      |  ^
       |
 
     Found 1 diagnostic
 
     ----- stderr -----
-    "###);
+    ");
     Ok(())
 }
 
@@ -146,57 +146,57 @@ fn test_respect_ignore_files() -> anyhow::Result<()> {
     "###);
 
     // Test that we can set to false via CLI
-    assert_cmd_snapshot!(case.command().arg("--no-respect-ignore-files"), @r###"
+    assert_cmd_snapshot!(case.command().arg("--no-respect-ignore-files"), @r"
     success: false
     exit_code: 1
     ----- stdout -----
-    error[invalid-syntax]
+    error[invalid-syntax]: Expected an expression
      --> test.py:1:2
       |
     1 | ~
-      |  ^ Expected an expression
+      |  ^
       |
 
     Found 1 diagnostic
 
     ----- stderr -----
-    "###);
+    ");
 
     // Test that we can set to false via config file
     case.write_file("ty.toml", "src.respect-ignore-files = false")?;
-    assert_cmd_snapshot!(case.command(), @r###"
+    assert_cmd_snapshot!(case.command(), @r"
     success: false
     exit_code: 1
     ----- stdout -----
-    error[invalid-syntax]
+    error[invalid-syntax]: Expected an expression
      --> test.py:1:2
       |
     1 | ~
-      |  ^ Expected an expression
+      |  ^
       |
 
     Found 1 diagnostic
 
     ----- stderr -----
-    "###);
+    ");
 
     // Ensure CLI takes precedence
     case.write_file("ty.toml", "src.respect-ignore-files = true")?;
-    assert_cmd_snapshot!(case.command().arg("--no-respect-ignore-files"), @r###"
+    assert_cmd_snapshot!(case.command().arg("--no-respect-ignore-files"), @r"
     success: false
     exit_code: 1
     ----- stdout -----
-    error[invalid-syntax]
+    error[invalid-syntax]: Expected an expression
      --> test.py:1:2
       |
     1 | ~
-      |  ^ Expected an expression
+      |  ^
       |
 
     Found 1 diagnostic
 
     ----- stderr -----
-    "###);
+    ");
     Ok(())
 }
 

crates/ty/tests/cli/python_environment.rs

@@ -655,15 +655,15 @@ fn config_file_annotation_showing_where_python_version_set_syntax_error() -> any
         ),
     ])?;
 
-    assert_cmd_snapshot!(case.command(), @r###"
+    assert_cmd_snapshot!(case.command(), @r#"
     success: false
     exit_code: 1
     ----- stdout -----
-    error[invalid-syntax]
+    error[invalid-syntax]: Cannot use `match` statement on Python 3.8 (syntax was added in Python 3.10)
      --> test.py:2:1
       |
     2 | match object():
-      | ^^^^^ Cannot use `match` statement on Python 3.8 (syntax was added in Python 3.10)
+      | ^^^^^
     3 |     case int():
     4 |         pass
       |
@@ -678,17 +678,17 @@ fn config_file_annotation_showing_where_python_version_set_syntax_error() -> any
     Found 1 diagnostic
 
     ----- stderr -----
-    "###);
+    "#);
 
-    assert_cmd_snapshot!(case.command().arg("--python-version=3.9"), @r###"
+    assert_cmd_snapshot!(case.command().arg("--python-version=3.9"), @r"
     success: false
     exit_code: 1
     ----- stdout -----
-    error[invalid-syntax]
+    error[invalid-syntax]: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
      --> test.py:2:1
       |
     2 | match object():
-      | ^^^^^ Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+      | ^^^^^
     3 |     case int():
     4 |         pass
       |
@@ -697,7 +697,7 @@ fn config_file_annotation_showing_where_python_version_set_syntax_error() -> any
     Found 1 diagnostic
 
     ----- stderr -----
-    "###);
+    ");
 
     Ok(())
 }

crates/ty_python_semantic/resources/mdtest/snapshots/semantic_syntax_erro…_-_Semantic_syntax_erro…_-_`async`_comprehensio…_-_Python_3.10_(96aa8ec77d46553d).snap

@@ -33,13 +33,13 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/semantic_syn
 # Diagnostics
 
 ```
-error[invalid-syntax]
+error[invalid-syntax]: cannot use an asynchronous comprehension inside of a synchronous comprehension on Python 3.10 (syntax was added in 3.11)
  --> src/mdtest_snippet.py:6:19
   |
 4 | async def f():
 5 |     # error: 19 [invalid-syntax] "cannot use an asynchronous comprehension inside of a synchronous comprehension on Python 3.10 (syntax…
 6 |     return {n: [x async for x in elements(n)] for n in range(3)}
-  |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot use an asynchronous comprehension inside of a synchronous comprehension on Python 3.10 (syntax was added in 3.11)
+  |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^
 7 | async def test():
 8 |     # error: [not-iterable] "Object of type `range` is not async-iterable"
   |

crates/ty_python_semantic/resources/mdtest/snapshots/version_related_synt…_-_Version-related_synt…_-_`match`_statement_-_Before_3.10_(2545eaa83b635b8b).snap

@@ -20,11 +20,11 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/version_rela
 # Diagnostics
 
 ```
-error[invalid-syntax]
+error[invalid-syntax]: Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
  --> src/mdtest_snippet.py:1:1
   |
 1 | match 2:  # error: 1 [invalid-syntax] "Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)"
-  | ^^^^^ Cannot use `match` statement on Python 3.9 (syntax was added in Python 3.10)
+  | ^^^^^
 2 |     case 1:
 3 |         print("it's one")
   |