53 lines
1.8 KiB
TypeScript
53 lines
1.8 KiB
TypeScript
import csv from "csvtojson"
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export async function jsonFromCsvString(csvString: string) {
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const possibleDelimiters = [",", ";", ":", "|", "~", "\t", " "]
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for (let i = 0; i < possibleDelimiters.length; i++) {
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let headers: string[] | undefined = undefined
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let headerMismatch = false
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try {
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// By default the csvtojson library casts empty values as empty strings. This
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// is causing issues on conversion. ignoreEmpty will remove the key completly
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// if empty, so creating this empty object will ensure we return the values
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// with the keys but empty values
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const result = await csv({
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ignoreEmpty: false,
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delimiter: possibleDelimiters[i],
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}).fromString(csvString)
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for (const [, row] of result.entries()) {
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// The purpose of this is to find rows that have been split
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// into the wrong number of columns - Any valid .CSV file will have
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// the same number of colums in each row
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// If the number of columms in each row is different to
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// the number of headers, this isn't the right delimiter
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const columns = Object.keys(row)
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if (headers == null) {
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headers = columns
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}
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if (headers.length === 1 || headers.length !== columns.length) {
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headerMismatch = true
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break
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}
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for (const header of headers) {
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if (row[header] === undefined || row[header] === "") {
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row[header] = null
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}
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}
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}
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if (headerMismatch) {
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continue
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} else {
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return result
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}
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} catch (err) {
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// Splitting on the wrong delimiter sometimes throws CSV parsing error
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// (eg unterminated strings), which tells us we've picked the wrong delimiter
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continue
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}
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}
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throw new Error("Unable to determine delimiter")
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}
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