From c47721674cb256e09a23cdcf4b0c6c7ca25a10b3 Mon Sep 17 00:00:00 2001
From: Micha Reiser <micha@reiser.io>
Date: Mon, 17 Apr 2023 07:57:35 +0200
Subject: [PATCH] Show line/column numbers for syntax errors

---
 crates/ruff/src/linter.rs          |  8 ++------
 crates/ruff/src/logging.rs         | 33 ++++++++++++++++++++++++++++++
 crates/ruff_cli/src/diagnostics.rs | 14 ++++++-------
 3 files changed, 42 insertions(+), 13 deletions(-)

diff --git a/crates/ruff/src/linter.rs b/crates/ruff/src/linter.rs
index 31bb9d2d3eeb53..82df045e535bd0 100644
--- a/crates/ruff/src/linter.rs
+++ b/crates/ruff/src/linter.rs
@@ -23,6 +23,7 @@ use crate::checkers::physical_lines::check_physical_lines;
 use crate::checkers::tokens::check_tokens;
 use crate::directives::Directives;
 use crate::doc_lines::{doc_lines_from_ast, doc_lines_from_tokens};
+use crate::logging::DisplayParseError;
 use crate::message::Message;
 use crate::noqa::add_noqa;
 use crate::registry::{AsRule, Rule};
@@ -296,12 +297,7 @@ pub fn add_noqa_to_path(path: &Path, package: Option<&Path>, settings: &Settings
 
     // Log any parse errors.
     if let Some(err) = error {
-        error!(
-            "{}{}{} {err:?}",
-            "Failed to parse ".bold(),
-            fs::relativize_path(path).bold(),
-            ":".bold()
-        );
+        error!("{}", DisplayParseError::new(err, locator.to_source_code()));
     }
 
     // Add any missing `# noqa` pragmas.
diff --git a/crates/ruff/src/logging.rs b/crates/ruff/src/logging.rs
index 49ee5a4ed59fe7..1607508ead2039 100644
--- a/crates/ruff/src/logging.rs
+++ b/crates/ruff/src/logging.rs
@@ -1,10 +1,15 @@
+use std::fmt::{Display, Formatter};
+use std::path::Path;
 use std::sync::Mutex;
 
+use crate::fs;
 use anyhow::Result;
 use colored::Colorize;
 use fern;
 use log::Level;
 use once_cell::sync::Lazy;
+use ruff_python_ast::source_code::SourceCode;
+use rustpython_parser::ParseError;
 
 pub(crate) static WARNINGS: Lazy<Mutex<Vec<&'static str>>> = Lazy::new(Mutex::default);
 
@@ -127,6 +132,34 @@ pub fn set_up_logging(level: &LogLevel) -> Result<()> {
     Ok(())
 }
 
+pub struct DisplayParseError<'a> {
+    error: ParseError,
+    source_code: SourceCode<'a, 'a>,
+}
+
+impl<'a> DisplayParseError<'a> {
+    pub fn new(error: ParseError, source_code: SourceCode<'a, 'a>) -> Self {
+        Self { error, source_code }
+    }
+}
+
+impl Display for DisplayParseError<'_> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let source_location = self.source_code.source_location(self.error.location);
+
+        write!(
+            f,
+            "{header} {path}{colon}{row}{colon}{column}{colon} {inner}",
+            header = "Failed to parse ".bold(),
+            path = fs::relativize_path(Path::new(&self.error.source_path)).bold(),
+            row = source_location.row,
+            column = source_location.column,
+            colon = ":".cyan(),
+            inner = &self.error.error
+        )
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::logging::LogLevel;
diff --git a/crates/ruff_cli/src/diagnostics.rs b/crates/ruff_cli/src/diagnostics.rs
index 1aba61f8267be2..b77a8431457c89 100644
--- a/crates/ruff_cli/src/diagnostics.rs
+++ b/crates/ruff_cli/src/diagnostics.rs
@@ -16,10 +16,11 @@ use similar::TextDiff;
 use ruff::fs;
 use ruff::jupyter::{is_jupyter_notebook, JupyterIndex, JupyterNotebook};
 use ruff::linter::{lint_fix, lint_only, FixTable, FixerResult, LinterResult};
+use ruff::logging::DisplayParseError;
 use ruff::message::Message;
 use ruff::settings::{flags, AllSettings, Settings};
 use ruff_python_ast::imports::ImportMap;
-use ruff_python_ast::source_code::SourceFileBuilder;
+use ruff_python_ast::source_code::{LineIndex, SourceCode, SourceFileBuilder};
 
 use crate::cache;
 
@@ -200,13 +201,12 @@ pub fn lint_path(
     let imports = imports.unwrap_or_default();
 
     if let Some(err) = parse_error {
-        // FIXME micha manually print parse errors to get line and column numbers
-        // Notify the user of any parse errors.
         error!(
-            "{}{}{} {err}",
-            "Failed to parse ".bold(),
-            fs::relativize_path(path).bold(),
-            ":".bold()
+            "{}",
+            DisplayParseError::new(
+                err,
+                SourceCode::new(&contents, &LineIndex::from_source_text(&contents))
+            )
         );
 
         // Purge the cache.