Enum TestingOutput 

pub enum TestingOutput {
    ToFile(PathBuf),
    ToWriter(Box<dyn Write + Send>),
    ToChannel(OutputSender),
}

Specifies where to write the output data of an integration test.

Output File Format

The output file is a JSONL (“JSON lines”) file. Each line in the file is a separate JSON object that represents one output sent by the node.

The following fields are present in each output object:

• id (string): The output identifier that was used when sending the output.
• data: The output data (if any), encoded as JSON.
  • see below for details on the encoding
• data_type (string or object): The arrow::datatypes::DataType of the output data
  • Serialized to JSON using the type’s serde::Serialize implementation.
• time_offset_secs (float, optional): The time offset in seconds between the start of the node and the time when the output was sent.
  • This field is omitted if the DORA_TEST_NO_OUTPUT_TIME_OFFSET environment is set.

Output Data Encoding

We use the following steps to encode the data field of each output object:

• Convert the data to a RecordBatch through:

  RecordBatch::try_from_iter([("inner", data)])

• Convert the RecordBatch to a JSON object through the arrow_json::ArrayWriter.

Variants

ToFile(PathBuf)

Writes the output to the given JSONL file.

The file will be created or overwritten.

ToWriter(Box<dyn Write + Send>)

Writes the output as JSONL file to the given writer.

ToChannel(OutputSender)

Sends each output as a JSON object to the paired OutputReceiver.

Create the pair with output_channel and read it with drain_outputs once the node has finished.

The channel is unbounded because nothing consumes it while the node runs. A bounded channel would deadlock as soon as a node emitted more outputs than its capacity: the node blocks waiting for the daemon’s reply to that very output, and the reply cannot be produced until the output is accepted.