From 4b3541b6eba878bb4e8a8b818abe53b1efb471a1 Mon Sep 17 00:00:00 2001
From: Wade Bourne <wade@wbourne.dev>
Date: Tue, 29 Nov 2022 12:46:04 -0800
Subject: [PATCH] v1.1.0

- Add support for retrieving parsed headers directly.
---
 package.json                |  2 +-
 src/__tests__/index.test.ts | 52 ++++++++++++++++++++++++++++++-------
 src/index.ts                | 10 ++++++-
 3 files changed, 53 insertions(+), 11 deletions(-)

diff --git a/package.json b/package.json
index 6271c61..db3a0ba 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "incremental-csv-parser",
-  "version": "1.0.2",
+  "version": "1.1.0",
   "description": "A simple, browser compatible, incremental CSV parser.",
   "main": "dist/cjs/index.js",
   "repository": "https://github.com/AllAwesome497/incremental-csv-parser",
diff --git a/src/__tests__/index.test.ts b/src/__tests__/index.test.ts
index 66bece5..8cf78f7 100644
--- a/src/__tests__/index.test.ts
+++ b/src/__tests__/index.test.ts
@@ -7,6 +7,7 @@ interface CSVParserTest {
   headers?: Array<string>;
   chunks: Array<string>;
   expected: Array<Record<string, string>>;
+  expectedHeaders?: Array<string>;
 }
 
 describe('SimpleCSVParser', () => {
@@ -105,17 +106,50 @@ describe('SimpleCSVParser', () => {
         { a: '5', b: '6', c: '7', d: '8' },
       ],
     },
-  ])('$name', ({ chunks, expected, headers }) => {
-    const results: Array<Record<string, string>> = [];
+    {
+      name: 'headers no data',
+      chunks: ['a,b,c,d\n'],
+      expected: [],
+      expectedHeaders: ['a', 'b', 'c', 'd'],
+    },
+    {
+      name: 'headers no data (no newline)',
+      chunks: ['a,b,c,d'],
+      expected: [],
+      expectedHeaders: ['a', 'b', 'c', 'd'],
+    },
+    {
+      name: 'manually defined headers',
+      chunks: [],
+      expected: [],
+      expectedHeaders: ['a', 'b', 'c'],
+      headers: ['a', 'b', 'c'],
+    }
+  ])(
+    '$name',
+    ({
+      chunks,
+      expected,
+      expectedHeaders = expected.length > 0
+        ? Object.keys(expected[0])
+        : undefined,
+      headers,
+    }) => {
+      const results: Array<Record<string, string>> = [];
 
-    const parser = new CSVParser((data) => results.push(data), headers);
+      const parser = new CSVParser((data) => results.push(data), headers);
 
-    for (const chunk of chunks) {
-      parser.process(chunk);
-    }
+      for (const chunk of chunks) {
+        parser.process(chunk);
+      }
 
-    parser.flush();
+      parser.flush();
 
-    expect(results).toEqual(expected);
-  });
+      expect(results).toEqual(expected);
+
+      if (expectedHeaders) {
+        expect(parser.headers()).toEqual(expectedHeaders);
+      }
+    },
+  );
 });
diff --git a/src/index.ts b/src/index.ts
index 40c20ec..ed7f525 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -118,7 +118,7 @@ export class CSVParser<K extends string> {
    * @throws Error if the stream did not end in a valid row.
    */
   flush() {
-    if ((!this._value && this._row.length === 0) || !this._headers) {
+    if (!this._value && this._row.length === 0) {
       // clean exit
       return;
     }
@@ -130,6 +130,14 @@ export class CSVParser<K extends string> {
     }
   }
 
+  /**
+   * Gets headers parsed for the csv.
+   * @returns Headers for the csv (or undefined if they haven't been parsed yet)
+   */
+  headers() {
+    return this._headers;
+  }
+
   protected _finalizeValue(rowEnd?: boolean) {
     // empty line
     if (!this._row.length && rowEnd && !this._value) {