json

JSON test reporter for dream_test.

This reporter outputs test results as JSON for CI/CD integration, test aggregation, and tooling.

Example Output

{
  "version": "1.0",
  "timestamp_ms": 1733151045123,
  "duration_ms": 315,
  "system": {
    "os": "darwin",
    "otp_version": "27",
    "gleam_version": "0.67.0"
  },
  "summary": {
    "total": 3,
    "passed": 2,
    "failed": 1,
    "skipped": 0,
    "pending": 0,
    "timed_out": 0,
    "setup_failed": 0
  },
  "tests": [
    {
      "name": "adds numbers",
      "full_name": ["Calculator", "add", "adds numbers"],
      "status": "passed",
      "duration_ms": 2,
      "tags": [],
      "kind": "unit",
      "failures": []
    }
  ]
}

Usage

import dream_test/reporter/json
import gleam/io

pub fn main() {
  to_test_cases("my_test", tests())
  |> run_all()
  |> json.report(io.print)
  |> exit_on_failure()
}

Combining with BDD Reporter

results
|> bdd.report(io.print)           // Human-readable to stdout
|> json.report(write_to_file)     // JSON to file
|> exit_on_failure()

Values

format

</>

pub fn format(results: List(types.TestResult)) -> String

Format test results as a compact JSON string.

Returns a single-line JSON string suitable for machine parsing.

Example

let json_string = format(results)
file.write("test-results.json", json_string)

format_pretty

</>

pub fn format_pretty(results: List(types.TestResult)) -> String

Format test results as pretty-printed JSON.

Returns an indented, human-readable JSON string with 2-space indentation.

Example

let json_string = format_pretty(results)
io.println(json_string)

report

</>

pub fn report(
  results: List(types.TestResult),
  write: fn(String) -> Nil,
) -> List(types.TestResult)

Print test results as JSON using a provided writer function.

This is the main entry point for JSON reporting. The writer function receives the JSON string and can print it, log it, or write it to a file.

Example

// Print to stdout
results |> json.report(io.print)

// Write to file
results |> json.report(fn(s) { file.write("results.json", s) })

Returns

Returns the input results unchanged, enabling pipeline composition:

to_test_cases("my_test", tests())
|> run_all()
|> bdd.report(io.print)
|> json.report(write_to_file)
|> exit_on_failure()

report_pretty

</>

pub fn report_pretty(
  results: List(types.TestResult),
  write: fn(String) -> Nil,
) -> List(types.TestResult)

Print test results as pretty-printed JSON using a provided writer function.

Same as report but with indented, human-readable output.

Example

results |> json.report_pretty(io.print)