fix(csv-parse): disable quoting for an empty Buffer

packages/csv-parse/lib/api/normalize_options.js

@@ -496,7 +496,8 @@ const normalize_options = function (opts) {
   if (
     options.quote === null ||
     options.quote === false ||
-    options.quote === ""
+    options.quote === "" ||
+    (Buffer.isBuffer(options.quote) && options.quote.length === 0)
   ) {
     options.quote = null;
   } else {

packages/csv-parse/test/option.quote.empty_buffer.js

@@ -0,0 +1,42 @@
+import assert from "node:assert/strict";
+import { parse, normalize_options } from "../lib/index.js";
+import { parse as parseSync } from "../lib/sync.js";
+
+describe("Option `quote` with an empty Buffer", function () {
+  for (const [input, expected] of [
+    [",", [["", ""]]],
+    ["\n", [[""]]],
+    [",a", [["", "a"]]],
+    ['"a",b', [['"a"', "b"]]],
+    ["", []],
+  ]) {
+    it(`disables quoting for ${JSON.stringify(input)}`, function () {
+      const options = { quote: Buffer.alloc(0) };
+      // Assert normalization first so a regression cannot enter a zero-length
+      // quote loop while testing delimiter-only input.
+      assert.equal(normalize_options(options).quote, null);
+      assert.deepEqual(parseSync(input, options), expected);
+      assert.deepEqual(parseSync(input, { quote: "" }), expected);
+    });
+  }
+
+  it("disables quoting for byte-sized stream writes", async function () {
+    const options = { quote: Buffer.alloc(0) };
+    assert.equal(normalize_options(options).quote, null);
+    const input = Buffer.from(',"a"\n,b');
+    const records = await new Promise((resolve, reject) => {
+      const parser = parse(options, (err, records) => {
+        if (err) return reject(err);
+        resolve(records);
+      });
+      for (let i = 0; i < input.length; i++) {
+        parser.write(input.subarray(i, i + 1));
+      }
+      parser.end();
+    });
+    assert.deepEqual(records, [
+      ["", '"a"'],
+      ["", "b"],
+    ]);
+  });
+});