From 1aace05a22c6fb2a4a5a24ebbdb9ac819ad9aabd Mon Sep 17 00:00:00 2001
From: Jian-Zhang08 <53095992+Jian-Zhang08@users.noreply.github.com>
Date: Fri, 26 Jun 2026 11:28:25 -0500
Subject: [PATCH] fix(csv-parse): preserve multi-byte record delimiter in raw
 output

With { raw: true }, only the first byte of the record delimiter was
appended to the raw buffer (in the per-char loop), and the parser then
advanced pos past the remaining delimiter bytes before emitting the
record. For multi-byte delimiters such as Windows "\r\n" this dropped
the trailing byte, so raw was 'a,b\r' instead of 'a,b\r\n'.

Append the remaining record-delimiter bytes to the raw buffer when a
delimiter is detected, so multi-byte delimiters are preserved in full.
Single-byte delimiters are unaffected (the loop body does not run).

Adds a regression test and rebuilds dist.

Fixes #332
---
 packages/csv-parse/dist/cjs/index.cjs  | 10 ++++++++++
 packages/csv-parse/dist/cjs/stream.cjs | 10 ++++++++++
 packages/csv-parse/dist/cjs/sync.cjs   | 10 ++++++++++
 packages/csv-parse/dist/esm/index.js   | 10 ++++++++++
 packages/csv-parse/dist/esm/sync.js    | 10 ++++++++++
 packages/csv-parse/dist/iife/index.js  | 10 ++++++++++
 packages/csv-parse/dist/iife/sync.js   | 10 ++++++++++
 packages/csv-parse/dist/umd/index.js   | 10 ++++++++++
 packages/csv-parse/dist/umd/sync.js    | 10 ++++++++++
 packages/csv-parse/lib/api/index.js    | 10 ++++++++++
 packages/csv-parse/test/option.raw.ts  | 13 +++++++++++++
 11 files changed, 113 insertions(+)

diff --git a/packages/csv-parse/dist/cjs/index.cjs b/packages/csv-parse/dist/cjs/index.cjs
index 4e029162..a74123f3 100644
--- a/packages/csv-parse/dist/cjs/index.cjs
+++ b/packages/csv-parse/dist/cjs/index.cjs
@@ -1360,6 +1360,16 @@ const transform = function (original_options = {}) {
               pos,
             );
             if (recordDelimiterLength !== 0) {
+              // Only the first byte of the record delimiter was appended to
+              // the raw buffer above; append the remaining bytes so that
+              // multi-byte delimiters such as "\r\n" are preserved in full in
+              // `raw` instead of being truncated when `pos` skips past them
+              // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+              if (raw === true) {
+                for (let i = 1; i < recordDelimiterLength; i++) {
+                  rawBuffer.append(buf[pos + i]);
+                }
+              }
               // Do not emit comments which take a full line
               const skipCommentLine =
                 this.state.commenting &&
diff --git a/packages/csv-parse/dist/cjs/stream.cjs b/packages/csv-parse/dist/cjs/stream.cjs
index 635049d6..a30286fc 100644
--- a/packages/csv-parse/dist/cjs/stream.cjs
+++ b/packages/csv-parse/dist/cjs/stream.cjs
@@ -1360,6 +1360,16 @@ const transform = function (original_options = {}) {
               pos,
             );
             if (recordDelimiterLength !== 0) {
+              // Only the first byte of the record delimiter was appended to
+              // the raw buffer above; append the remaining bytes so that
+              // multi-byte delimiters such as "\r\n" are preserved in full in
+              // `raw` instead of being truncated when `pos` skips past them
+              // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+              if (raw === true) {
+                for (let i = 1; i < recordDelimiterLength; i++) {
+                  rawBuffer.append(buf[pos + i]);
+                }
+              }
               // Do not emit comments which take a full line
               const skipCommentLine =
                 this.state.commenting &&
diff --git a/packages/csv-parse/dist/cjs/sync.cjs b/packages/csv-parse/dist/cjs/sync.cjs
index 835b51c5..b9d835e1 100644
--- a/packages/csv-parse/dist/cjs/sync.cjs
+++ b/packages/csv-parse/dist/cjs/sync.cjs
@@ -1358,6 +1358,16 @@ const transform = function (original_options = {}) {
               pos,
             );
             if (recordDelimiterLength !== 0) {
+              // Only the first byte of the record delimiter was appended to
+              // the raw buffer above; append the remaining bytes so that
+              // multi-byte delimiters such as "\r\n" are preserved in full in
+              // `raw` instead of being truncated when `pos` skips past them
+              // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+              if (raw === true) {
+                for (let i = 1; i < recordDelimiterLength; i++) {
+                  rawBuffer.append(buf[pos + i]);
+                }
+              }
               // Do not emit comments which take a full line
               const skipCommentLine =
                 this.state.commenting &&
diff --git a/packages/csv-parse/dist/esm/index.js b/packages/csv-parse/dist/esm/index.js
index b583dbc7..ac3b06b7 100644
--- a/packages/csv-parse/dist/esm/index.js
+++ b/packages/csv-parse/dist/esm/index.js
@@ -6409,6 +6409,16 @@ const transform = function (original_options = {}) {
               pos,
             );
             if (recordDelimiterLength !== 0) {
+              // Only the first byte of the record delimiter was appended to
+              // the raw buffer above; append the remaining bytes so that
+              // multi-byte delimiters such as "\r\n" are preserved in full in
+              // `raw` instead of being truncated when `pos` skips past them
+              // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+              if (raw === true) {
+                for (let i = 1; i < recordDelimiterLength; i++) {
+                  rawBuffer.append(buf[pos + i]);
+                }
+              }
               // Do not emit comments which take a full line
               const skipCommentLine =
                 this.state.commenting &&
diff --git a/packages/csv-parse/dist/esm/sync.js b/packages/csv-parse/dist/esm/sync.js
index 8865f324..c9021785 100644
--- a/packages/csv-parse/dist/esm/sync.js
+++ b/packages/csv-parse/dist/esm/sync.js
@@ -3328,6 +3328,16 @@ const transform = function (original_options = {}) {
               pos,
             );
             if (recordDelimiterLength !== 0) {
+              // Only the first byte of the record delimiter was appended to
+              // the raw buffer above; append the remaining bytes so that
+              // multi-byte delimiters such as "\r\n" are preserved in full in
+              // `raw` instead of being truncated when `pos` skips past them
+              // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+              if (raw === true) {
+                for (let i = 1; i < recordDelimiterLength; i++) {
+                  rawBuffer.append(buf[pos + i]);
+                }
+              }
               // Do not emit comments which take a full line
               const skipCommentLine =
                 this.state.commenting &&
diff --git a/packages/csv-parse/dist/iife/index.js b/packages/csv-parse/dist/iife/index.js
index 362b6137..d62fdeda 100644
--- a/packages/csv-parse/dist/iife/index.js
+++ b/packages/csv-parse/dist/iife/index.js
@@ -6412,6 +6412,16 @@ var csv_parse = (function (exports) {
                           pos,
                         );
                         if (recordDelimiterLength !== 0) {
+                          // Only the first byte of the record delimiter was appended to
+                          // the raw buffer above; append the remaining bytes so that
+                          // multi-byte delimiters such as "\r\n" are preserved in full in
+                          // `raw` instead of being truncated when `pos` skips past them
+                          // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+                          if (raw === true) {
+                            for (let i = 1; i < recordDelimiterLength; i++) {
+                              rawBuffer.append(buf[pos + i]);
+                            }
+                          }
                           // Do not emit comments which take a full line
                           const skipCommentLine =
                             this.state.commenting &&
diff --git a/packages/csv-parse/dist/iife/sync.js b/packages/csv-parse/dist/iife/sync.js
index d9f6b67c..2308b562 100644
--- a/packages/csv-parse/dist/iife/sync.js
+++ b/packages/csv-parse/dist/iife/sync.js
@@ -3331,6 +3331,16 @@ var csv_parse_sync = (function (exports) {
                           pos,
                         );
                         if (recordDelimiterLength !== 0) {
+                          // Only the first byte of the record delimiter was appended to
+                          // the raw buffer above; append the remaining bytes so that
+                          // multi-byte delimiters such as "\r\n" are preserved in full in
+                          // `raw` instead of being truncated when `pos` skips past them
+                          // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+                          if (raw === true) {
+                            for (let i = 1; i < recordDelimiterLength; i++) {
+                              rawBuffer.append(buf[pos + i]);
+                            }
+                          }
                           // Do not emit comments which take a full line
                           const skipCommentLine =
                             this.state.commenting &&
diff --git a/packages/csv-parse/dist/umd/index.js b/packages/csv-parse/dist/umd/index.js
index 4c5728e2..a856d867 100644
--- a/packages/csv-parse/dist/umd/index.js
+++ b/packages/csv-parse/dist/umd/index.js
@@ -6415,6 +6415,16 @@
                           pos,
                         );
                         if (recordDelimiterLength !== 0) {
+                          // Only the first byte of the record delimiter was appended to
+                          // the raw buffer above; append the remaining bytes so that
+                          // multi-byte delimiters such as "\r\n" are preserved in full in
+                          // `raw` instead of being truncated when `pos` skips past them
+                          // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+                          if (raw === true) {
+                            for (let i = 1; i < recordDelimiterLength; i++) {
+                              rawBuffer.append(buf[pos + i]);
+                            }
+                          }
                           // Do not emit comments which take a full line
                           const skipCommentLine =
                             this.state.commenting &&
diff --git a/packages/csv-parse/dist/umd/sync.js b/packages/csv-parse/dist/umd/sync.js
index e2218aae..babe6d0d 100644
--- a/packages/csv-parse/dist/umd/sync.js
+++ b/packages/csv-parse/dist/umd/sync.js
@@ -3334,6 +3334,16 @@
                           pos,
                         );
                         if (recordDelimiterLength !== 0) {
+                          // Only the first byte of the record delimiter was appended to
+                          // the raw buffer above; append the remaining bytes so that
+                          // multi-byte delimiters such as "\r\n" are preserved in full in
+                          // `raw` instead of being truncated when `pos` skips past them
+                          // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+                          if (raw === true) {
+                            for (let i = 1; i < recordDelimiterLength; i++) {
+                              rawBuffer.append(buf[pos + i]);
+                            }
+                          }
                           // Do not emit comments which take a full line
                           const skipCommentLine =
                             this.state.commenting &&
diff --git a/packages/csv-parse/lib/api/index.js b/packages/csv-parse/lib/api/index.js
index 6cd8e3fe..1d889e93 100644
--- a/packages/csv-parse/lib/api/index.js
+++ b/packages/csv-parse/lib/api/index.js
@@ -336,6 +336,16 @@ const transform = function (original_options = {}) {
               pos,
             );
             if (recordDelimiterLength !== 0) {
+              // Only the first byte of the record delimiter was appended to
+              // the raw buffer above; append the remaining bytes so that
+              // multi-byte delimiters such as "\r\n" are preserved in full in
+              // `raw` instead of being truncated when `pos` skips past them
+              // below (e.g. `raw: 'a,b\r'` instead of `raw: 'a,b\r\n'`). (#332)
+              if (raw === true) {
+                for (let i = 1; i < recordDelimiterLength; i++) {
+                  rawBuffer.append(buf[pos + i]);
+                }
+              }
               // Do not emit comments which take a full line
               const skipCommentLine =
                 this.state.commenting &&
diff --git a/packages/csv-parse/test/option.raw.ts b/packages/csv-parse/test/option.raw.ts
index a6fdccfc..d923e909 100644
--- a/packages/csv-parse/test/option.raw.ts
+++ b/packages/csv-parse/test/option.raw.ts
@@ -56,6 +56,19 @@ describe("Option `raw`", function () {
     });
   });
 
+  it("preserves windows (CRLF) record delimiters", function (next) {
+    // The `\n` of a `\r\n` record delimiter used to be dropped from `raw`,
+    // yielding `a,b\r` instead of `a,b\r\n`. (#332)
+    parse("a,b\r\nc,d\r\n", { raw: true }, (err, records) => {
+      if (err) return next(err);
+      const raws = (
+        records as unknown as { record: string[]; raw: string }[]
+      ).map((r) => r.raw);
+      raws.should.eql(["a,b\r\n", "c,d\r\n"]);
+      next();
+    });
+  });
+
   it("preserve columns", function (next) {
     parse(
       dedent`