Sample

Define a NimbleCSV parser module and parse and dump CSV with it: header skipping, quoted fields holding separators and newlines, parse errors, and iodata output

sha256:5cc42ad8f6260280ff21c0786a675829539b5451403d0a85eaeda6db06e16e3a

Case

Goal

Define a NimbleCSV parser module and parse and dump CSV with it: header skipping, quoted fields holding separators and newlines, parse errors, and iodata output HOW

Packages

nimble_csv 1.3.0

Environment

elixir 1

Created

2026-08-14T20:10:34Z

Contract

• assert NimbleCSV.define/2 is an ordinary function and not a macro, so it can be called at runtime, and that calling it a second time emits a redefining module warning on stderr
• assert a bare alias passed to define/2 creates a top-level module rather than one nested under the enclosing module
• assert a parser defined with a separator list round-trips a table, accepts every separator when parsing but writes only the first when dumping, and treats all of them as reserved characters
• assert the RFC4180 parser keeps a separator and a newline that sit inside a quoted field, returns the inner newline bytes verbatim rather than normalising CRLF to LF, and reads a doubled quote as one literal quote
• assert parse_string discards the first line by default, so a headerless single-row CSV parses to an empty list, and that skip_headers: false keeps it
• assert broken escaping raises NimbleCSV.ParseError with either the end-of-file or the unexpected-escape-character message, while a ragged row of the wrong width raises nothing and is returned as-is
• assert eager parse_string and parse_enumerable raise before yielding any row, while lazy parse_stream returns the rows before the broken line when the stream is halted early
• assert dump_to_iodata returns a nested list holding binaries and raw single-byte integers rather than a binary, that RFC4180 dumps CRLF row terminators while a custom parser can dump LF, that reserved characters are quoted on the way out, and that entries are dumped through to_string while parsing always returns binaries

Files

• csx.json
• lib/csx_nimble_csv/parsers.ex
• mix.exs
• mix.lock
• test/contract_test.exs
• test/test_helper.exs

Download the verified artifact (tar.gz) — the exact bytes the contract ran against

Origin Seeder

anonymous

Verification receipts

• elixir 1 · CONTAINER_RUN · compile:PASS · contract:PASS · load:PASS · resolve:PASS · hex@1 · 2026-08-14 · ed25519:a2ec939a4c60e243