CSV parse - setting cast_date to true is converting unparsable strings to dates

[katherinea]

Describe the bug
Using csv-parse: 5.0.4

When cast_date is set to true, if you parse a string that ends with a number, the string is cast to a date.
According to the docs https://csv.js.org/parse/options/cast_date/, "The implementation relies on Date.parse. The CSV value is left untouched if the function returns NaN."

Date.parse("Test 2") => NaN, however the parsed field is returned as 2001-02-01T00:00:00.000Z

To Reproduce

with file test.csv

title
test 2

and implementation

  async parseCsv<T>(filePath: string): Promise<T[]> {
    const content: Buffer = await fs.readFile(filePath)
    const parsed: T[] = parse(content, {
      cast: true,
      cast_date: true,
      columns: true,
    })

    return parsed
  }

returned data is:

{
  title: 2001-02-01T00:00:00.000Z,
}

[wdavidw]

Hum, as a matter of fact, node -e 'console.info(Date.parse("Test 2"))' return 980982000000 (using Node.js v16.13.0). This comes as a surprise, but it explains the behavior. You can always write you own cast_date function.

[katherinea]

Hiya! Right sorry you're correct on that parsing.
Strange behaviour as

Date.parse("Test 2")
=> 980985600000
Date.parse("Test 2 v 2")
=> NaN

I've tried to pass a function to cast_date but am getting an error message. With the following parsing options:

const parsed: T[] = parse(content, {
      cast: true,
      cast_date: (value: string, context: CastingContext) => {
        const date = Date.parse(value)
        // test function, not correctly handling non-date strings
        return new Date(date)
      },
      columns: true,
    })

I'm getting the error:

{
   "type": "CsvError",
   "message": "Invalid option cast_date: cast_date must be true or a function, got undefined",
   "stack":
       Error: Invalid option cast_date: cast_date must be true or a function, got undefined
           at Parser.__normalizeOptions (/Users/katherine/RAcode/powertools/bulk-events-upload/node_modules/csv-parse/dist/cjs/sync.cjs:206:13)
           at new Parser (/Users/katherine/RAcode/powertools/bulk-events-upload/node_modules/csv-parse/dist/cjs/sync.cjs:153:10)
           at parse (/Users/katherine/RAcode/powertools/bulk-events-upload/node_modules/csv-parse/dist/cjs/sync.cjs:1281:18)
           at _callee$ (/Users/katherine/RAcode/powertools/bulk-events-upload/src/services/csv-service/csv-service.ts:15:25)
           at tryCatch (/Users/katherine/RAcode/powertools/bulk-events-upload/node_modules/regenerator-runtime/runtime.js:63:40)
           at Generator.invoke [as _invoke] (/Users/katherine/RAcode/powertools/bulk-events-upload/node_modules/regenerator-runtime/runtime.js:294:22)
           at Generator.next (/Users/katherine/RAcode/powertools/bulk-events-upload/node_modules/regenerator-runtime/runtime.js:119:21)
           at asyncGeneratorStep (/Users/katherine/RAcode/powertools/bulk-events-upload/node_modules/@babel/runtime/helpers/asyncToGenerator.js:3:24)
           at _next (/Users/katherine/RAcode/powertools/bulk-events-upload/node_modules/@babel/runtime/helpers/asyncToGenerator.js:25:9)
   "code": "CSV_INVALID_OPTION_CAST_DATE"
 }

Also had a question about the types - cast_date takes a CastingDateFunction

CastingDateFunction = (value: string, context: CastingContext) => Date;

Shouldn't the return type be Date | string to allow for strings to be returned if they're not able to be parsed as a date?
Thank you :)

[wdavidw]

Strange, option cast_date was defined in sync.t.ts but not implemented nowhere.