provides more robust .csv handling with various delimiters

packages/builder/src/components/backend/TableNavigator/utils.js

@@ -58,7 +58,7 @@ export const parseFile = e => {
             resolveRows(rows)
           })
           .catch(() => {
-            reject("cannot parse csv.")
+            reject("cannot parse csv")
           })
       }
     })

packages/server/src/utilities/csv.ts

@@ -7,6 +7,7 @@ export async function jsonFromCsvString(csvString: string) {
     let numOfHeaders: number | undefined = undefined
     let headerMismatch = false
 
+    try {
       const castedWithEmptyValues = await csv({
         ignoreEmpty: true,
         delimiter: possibleDelimeters[i],
@@ -21,20 +22,25 @@ export async function jsonFromCsvString(csvString: string) {
         delimiter: possibleDelimeters[i],
       }).fromString(csvString)
       for (const [i, r] of result.entries()) {
+        // The purpose of this is to find rows that have been split
+        // into the wrong number of columns - Any valid .CSV file will have
+        // the same number of colums in each row
+        // If the number of columms in each row is different to
+        // the number of headers, this isn't the right delimiter
         const columns = Object.keys(r)
         if (numOfHeaders == null) {
           numOfHeaders = columns.length
         }
-      if (numOfHeaders !== columns.length) {
+        if (numOfHeaders === 1 || numOfHeaders !== columns.length) {
           headerMismatch = true
           break
         }
         for (const [key] of Object.entries(r).filter(
           ([, value]) => value === ""
         )) {
-        // if (castedWithEmptyValues[i][key] === undefined) {
+          if (castedWithEmptyValues[i][key] === undefined) {
-        //   r[key] = null
+            r[key] = null
-        // }
+          }
         }
       }
       if (headerMismatch) {
@@ -42,6 +48,11 @@ export async function jsonFromCsvString(csvString: string) {
       } else {
         return result
       }
+    } catch (err) {
+      // Splitting on the wrong delimiter sometimes throws CSV parsing error
+      // (eg unterminated strings), which tells us we've picked the wrong delimiter
+      continue
+    }
   }
   throw new Error("Unable to determine delimiter")
 }