Improvement error message (#33)

Author: ppputtyo

Cargo.lock

@@ -11,6 +11,7 @@ repository.workspace = true
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+annotate-snippets = "0.9.1"
 indexmap = "1.9.3"
 itertools = "0.10.3"
 once_cell = "1.17.0"

crates/uroborosql-fmt/Cargo.toml

@@ -31,7 +31,7 @@ use tree_sitter::{Node, Point, Range};
 
 use crate::{config::CONFIG, error::UroboroSQLFmtError};
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub(crate) struct Position {
     pub(crate) row: usize,
     pub(crate) col: usize,
@@ -46,7 +46,7 @@ impl Position {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 pub(crate) struct Location {
     pub(crate) start_position: Position,
     pub(crate) end_position: Position,

crates/uroborosql-fmt/src/cst.rs

@@ -1,4 +1,10 @@
-use crate::config::CONFIG;
+use annotate_snippets::{
+    display_list::{DisplayList, FormatOptions},
+    snippet::{AnnotationType, Slice, Snippet, SourceAnnotation},
+};
+use itertools::Itertools;
+
+use crate::{config::CONFIG, cst::Location, error::UroboroSQLFmtError};
 
 /// 設定ファイルに合わせて予約後の大文字・小文字を変換する
 pub(crate) fn convert_keyword_case(keyword: &str) -> String {
@@ -72,3 +78,91 @@ pub(crate) fn is_line_overflow(char_len: usize) -> bool {
         char_len >= max_char_per_line as usize
     }
 }
+
+/// xバイト目が何文字目かを返す
+fn byte_to_char_index(input: &str, target_byte_index: usize) -> Result<usize, UroboroSQLFmtError> {
+    let mut char_index = 0;
+    let mut byte_index = 0;
+
+    for c in input.chars() {
+        if byte_index == target_byte_index {
+            return Ok(char_index);
+        }
+        char_index += 1;
+        byte_index += c.len_utf8();
+    }
+
+    if byte_index == target_byte_index {
+        Ok(char_index)
+    } else {
+        Err(UroboroSQLFmtError::Runtime(format!(
+            "byte_to_char_index: byte_index({}) is out of range",
+            target_byte_index
+        )))
+    }
+}
+
+/// エラー注釈を作成する関数
+/// 以下の形のエラー注釈を生成
+///
+/// ```sh
+///   |
+/// 2 | using tbl_b b
+///   | ^^^^^^^^^^^^^ {label}
+///   |
+/// ```
+pub(crate) fn create_error_annotation(
+    location: &Location,
+    label: &str,
+    src: &str,
+) -> Result<String, UroboroSQLFmtError> {
+    // 元のSQLのエラーが発生した行を取得
+    let source = src
+        .lines()
+        .enumerate()
+        .filter(|(i, _)| (location.start_position.row..=location.end_position.row).contains(i))
+        .map(|(_, x)| x)
+        .join("\n");
+
+    // エラー発生箇所の開始位置
+    // locaton.start_position.colはバイト数を指しているので文字数に変換する
+    let start_point = byte_to_char_index(
+        src.lines().collect_vec()[location.start_position.row],
+        location.start_position.col,
+    )?;
+
+    // エラー発生箇所の終了位置
+    // = (終了位置までの行の文字数合計) + (終了位置の行の終了位置までの文字数)
+    let end_point = src
+        .lines()
+        .enumerate()
+        .filter(|(i, _)| (location.start_position.row..location.end_position.row).contains(i))
+        .map(|(_, x)| x.chars().count() + 1) // 改行コードの分1プラスする
+        .sum::<usize>()
+        + byte_to_char_index(
+            src.lines().collect_vec()[location.end_position.row],
+            location.end_position.col,
+        )?; // エラー発生行の終了位置までの文字数 (locaton.end_position.colはバイト数を指しているので文字数に変換する)
+
+    let snippet = Snippet {
+        title: None,
+        footer: vec![],
+        slices: vec![Slice {
+            source: &source,
+            line_start: location.start_position.row + 1,
+            origin: None,
+            fold: true,
+            annotations: vec![SourceAnnotation {
+                label,
+                annotation_type: AnnotationType::Error,
+                range: (start_point, end_point),
+            }],
+        }],
+        opt: FormatOptions {
+            color: true,
+            ..Default::default()
+        },
+    };
+
+    Ok(DisplayList::from(snippet).to_string())
+}