Respect header row order when resolving conflicts

Author: visnup

src/xlsx.js

@@ -16,9 +16,9 @@ export class ExcelWorkbook {
 
 function extract(sheet, {range, headers}) {
   let [[c0, r0], [c1, r1]] = parseRange(range, sheet);
-  const headerRow = headers && sheet._rows[r0++];
   const seen = new Set();
   const names = [];
+  const headerRow = headers && sheet._rows[r0++];
   function name(n) {
     if (!names[n]) {
       let name = (headerRow ? valueOf(headerRow._cells[n]) : AA(n)) || AA(n);
@@ -27,6 +27,7 @@ function extract(sheet, {range, headers}) {
     }
     return names[n];
   }
+  if (headerRow) for (let c = c0; c <= c1; c++) name(c);
 
   const output = new Array(r1 - r0 + 1).fill({});
   for (let r = r0; r <= r1; r++) {

test/xlsx-test.js

@@ -64,15 +64,15 @@ test("FileAttachment.xlsx reads sheets with headers", (t) => {
   const workbook = new ExcelWorkbook(
     mockWorkbook({
       Sheet1: [
-        ["one", "one", "one", "two"],
-        [1, null, 3, 4],
-        [5, 6, 7, 8],
+        [null, "one", "one", "two", "A"],
+        [   1,  null,     3,     4,   5],
+        [   6,     7,     8,     9,  10],
       ],
     })
   );
   t.same(workbook.sheet(0, {headers: true}), [
-    {one: 1, one_: 3, two: 4},
-    {one: 5, one__: 6, one_: 7, two: 8},
+    {A: 1, one_: 3, two: 4, A_: 5},
+    {A: 6, one: 7, one_: 8, two: 9, A_: 10},
   ]);
   t.end();
 });