feat: add parseWithComments with correct span serialization

Uses js_sys::Object to build the result directly instead of
double-serializing through serde_json::Value. Statements and
comments are both serialized via serde_wasm_bindgen separately.

Author: elliots

Cargo.lock

@@ -16,6 +16,7 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 serde-wasm-bindgen = "0.6"
 console_error_panic_hook = "0.1"
+js-sys = "0.3"
 
 [profile.release]
 opt-level = "s"

Cargo.toml

@@ -4,7 +4,7 @@
  */
 
 // Parser
-export { Parser, init, parse, validate, format } from './parser.js';
+export { Parser, init, parse, parseWithComments, validate, format } from './parser.js';
 export type { ParserOptions, DialectInput } from './parser.js';
 
 // Dialects

src/index.ts

@@ -4,6 +4,7 @@ use sqlparser::dialect::{
     GenericDialect, HiveDialect, MsSqlDialect, MySqlDialect, OracleDialect, PostgreSqlDialect,
     RedshiftSqlDialect, SQLiteDialect, SnowflakeDialect,
 };
+use sqlparser::ast::comments::{Comment as SqlComment, CommentWithSpan};
 use sqlparser::parser::Parser;
 use wasm_bindgen::prelude::*;
 
@@ -163,6 +164,69 @@ pub fn get_supported_dialects() -> JsValue {
     serde_wasm_bindgen::to_value(&dialects).unwrap()
 }
 
+/// A serializable source comment
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SerializedComment {
+    pub comment_type: String,
+    pub content: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub prefix: Option<String>,
+    pub start_line: u64,
+    pub start_column: u64,
+    pub end_line: u64,
+    pub end_column: u64,
+}
+
+impl From<&CommentWithSpan> for SerializedComment {
+    fn from(c: &CommentWithSpan) -> Self {
+        let (comment_type, content, prefix) = match &c.comment {
+            SqlComment::SingleLine { content, prefix } => {
+                ("singleLine".to_string(), content.clone(), Some(prefix.clone()))
+            }
+            SqlComment::MultiLine(content) => {
+                ("multiLine".to_string(), content.clone(), None)
+            }
+        };
+        SerializedComment {
+            comment_type, content, prefix,
+            start_line: c.span.start.line,
+            start_column: c.span.start.column,
+            end_line: c.span.end.line,
+            end_column: c.span.end.column,
+        }
+    }
+}
+
+/// Parse SQL and return both AST and source comments
+#[wasm_bindgen]
+pub fn parse_sql_with_comments(dialect: &str, sql: &str) -> Result<JsValue, JsValue> {
+    let dialect_impl = get_dialect(dialect);
+    let (statements, comments) =
+        Parser::parse_sql_with_comments(dialect_impl.as_ref(), sql).map_err(|e| {
+            let error = ParseError {
+                message: e.to_string(),
+                line: None,
+                column: None,
+            };
+            serde_wasm_bindgen::to_value(&error).unwrap_or(JsValue::from_str(&e.to_string()))
+        })?;
+
+    let comments_vec: Vec<CommentWithSpan> = comments.into();
+    let serialized_comments: Vec<SerializedComment> =
+        comments_vec.iter().map(SerializedComment::from).collect();
+
+    // Build JS object manually to avoid double-serialization
+    let obj = js_sys::Object::new();
+    let stmts_val = serde_wasm_bindgen::to_value(&statements)
+        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))?;
+    let comments_val = serde_wasm_bindgen::to_value(&serialized_comments)
+        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))?;
+    js_sys::Reflect::set(&obj, &"statements".into(), &stmts_val).unwrap();
+    js_sys::Reflect::set(&obj, &"comments".into(), &comments_val).unwrap();
+    Ok(obj.into())
+}
+
 /// Validate SQL syntax without returning the full AST
 #[wasm_bindgen]
 pub fn validate_sql(dialect: &str, sql: &str) -> Result<bool, JsValue> {

src/lib.rs

@@ -2,6 +2,7 @@ import type { Dialect, DialectName } from './dialects.js';
 import { dialectFromString, GenericDialect } from './dialects.js';
 import { ParserError } from './types/errors.js';
 import type { Statement } from './types/ast.js';
+import type { SourceComment, ParseWithCommentsResult } from './types/comments.js';
 import { getWasmModule } from './wasm.js';
 
 export { init } from './wasm.js';
@@ -80,13 +81,28 @@ export class Parser {
     }
   }
 
+  /** Parse SQL and return both AST and source comments */
+  parseWithComments(sql: string): ParseWithCommentsResult<Statement> {
+    const wasm = getWasmModule();
+    try {
+      return wasm.parse_sql_with_comments(this.dialect.name, sql) as ParseWithCommentsResult<Statement>;
+    } catch (error) {
+      throw ParserError.fromWasmError(error);
+    }
+  }
+
   // Static methods
 
   /** Parse SQL into AST */
   static parse(sql: string, dialect: DialectInput = 'generic'): Statement[] {
     return new Parser(resolveDialect(dialect)).parse(sql);
   }
 
+  /** Parse SQL and return both AST and source comments */
+  static parseWithComments(sql: string, dialect: DialectInput = 'generic'): ParseWithCommentsResult<Statement> {
+    return new Parser(resolveDialect(dialect)).parseWithComments(sql);
+  }
+
   /** Parse SQL and return AST as JSON string */
   static parseToJson(sql: string, dialect: DialectInput = 'generic'): string {
     const wasm = getWasmModule();
@@ -145,6 +161,13 @@ export function parse(sql: string, dialect: DialectInput = 'generic'): Statement
   return Parser.parse(sql, dialect);
 }
 
+/**
+ * Parse SQL and return both AST and source comments
+ */
+export function parseWithComments(sql: string, dialect: DialectInput = 'generic'): ParseWithCommentsResult<Statement> {
+  return Parser.parseWithComments(sql, dialect);
+}
+
 /**
  * Validate SQL syntax
  * @throws ParserError if SQL is invalid

src/parser.ts

@@ -0,0 +1,23 @@
+/** A source code comment extracted from parsed SQL */
+export interface SourceComment {
+  /** "singleLine" for -- comments, "multiLine" for block comments */
+  commentType: 'singleLine' | 'multiLine'
+  /** The comment text content (excluding markers) */
+  content: string
+  /** For single-line comments, the prefix (e.g. "--", "#") */
+  prefix?: string
+  /** Start line (1-based) */
+  startLine: number
+  /** Start column (1-based) */
+  startColumn: number
+  /** End line (1-based) */
+  endLine: number
+  /** End column (1-based) */
+  endColumn: number
+}
+
+/** Result of parsing SQL with comments */
+export interface ParseWithCommentsResult<T> {
+  statements: T[]
+  comments: SourceComment[]
+}

src/types/comments.ts

@@ -1,2 +1,3 @@
 export * from './ast.js';
 export * from './errors.js';
+export * from './comments.js';

src/types/index.ts

@@ -4,6 +4,7 @@ import { WasmInitError } from './types/errors.js';
 export interface WasmModule {
   parse_sql: (dialect: string, sql: string) => unknown;
   parse_sql_with_options: (dialect: string, sql: string, options: unknown) => unknown;
+  parse_sql_with_comments: (dialect: string, sql: string) => unknown;
   parse_sql_to_json_string: (dialect: string, sql: string) => string;
   parse_sql_to_string: (dialect: string, sql: string) => string;
   format_sql: (dialect: string, sql: string) => string;