Case-insensitive mapping

Author: ivansg44

lib/DataHarmonizer.js

@@ -1489,8 +1489,16 @@ class DataHarmonizer {
     // Map current column indices to their indices in matrix to map
     const headerMap = {};
     const unmappedHeaders = [];
-    for (const [i, expectedVal] of expectedSecondaryHeaders.entries()) {
+    for (let [i, expectedVal] of expectedSecondaryHeaders.entries()) {
       headerMap[i] = actualSecondaryHeaders.findIndex((actualVal) => {
+        // Case insensitivity
+        if (typeof actualVal === 'string' || actualVal instanceof String) {
+          actualVal = actualVal.toLowerCase()
+        }
+        if (typeof expectedVal === 'string' || expectedVal instanceof String) {
+          expectedVal = expectedVal.toLowerCase()
+        }
+
         return actualVal === expectedVal;
       });
       if (headerMap[i] === -1) {