E81007: @Test program has no assertions and no expected output files

What went wrong

A @Test program has neither assertions nor expected output files. The test validates nothing - it would always pass (false confidence).

Worked examples

Compilable examples demonstrating this error and the correct fix:

• ek9 -q 809 (How does EK9 enforce test quality at compile time?)
• ek9 -q 804 (Why does EK9 have a built-in test framework instead of us...)
• ek9 -q 806 (How do I group tests and control execution order in EK9?)

[EK9 TESTING APPROACHES]

1. Assert-based: use assert/assertThrows in code (unit tests)
2. Black-box: expected_output.txt or expected_case_*.txt (regression)
3. Hybrid: both assertions and expected output files

How to fix it

1. Add assertions: `assert result == 4`
2. Or add expected_output.txt with expected stdout
3. Or remove @Test if it's not actually a test

Rationale

Tests that validate nothing mask real bugs. EK9 catches this at compile time - other languages only discover it when bugs slip through.

Examples

Every example is compiled by the EK9 compiler: the first fails exactly as captioned, the others fix it.

Fails with E81007: @Test program has no assertions and no expected output files - reported by the test runner, not the compiler, when ek9 -t greeting.ek9 runs in this project.

bad/greeting.ek9

#!ek9
defines module error.e81007.bad

  defines function

    greeting() as pure
      -> name as String
      <- result as String: `Hello, ${name}`

bad/dev/tests.ek9

#!ek9
defines module error.e81007.bad.tests

  references
    error.e81007.bad::greeting

  defines program

    @Test
    GreetingOnce()
      stdout <- Stdout()
      stdout.println(greeting("EK9"))

$ ek9 -t greeting.ek9
ek9: compilation failed (exit 8)
EK9     : PRE_IR_CHECKS: Errors in ./dev/tests.ek9
EK9     : Error   : E81007: 'GreetingOnce' on line 10 position 4: 'error.e81007.bad.tests::GreetingOnce' has no assertions and no expected output files: @Test program has no assertions and no expected output files
             See: ek9 -h E81007
EK9     : Compilation failed

Fixed: expected_output.txt says what the test must print

good/greeting.ek9

#!ek9
defines module error.e81007.good

  defines function

    greeting() as pure
      -> name as String
      <- result as String: `Hello, ${name}`

good/dev/tests.ek9

#!ek9
defines module error.e81007.good.tests

  references
    error.e81007.good::greeting

  defines program

    @Test
    GreetingOnce()
      stdout <- Stdout()
      stdout.println(greeting("EK9"))

good/dev/expected_output.txt

Hello, EK9

$ ek9 -t greeting.ek9
ℹ️ Found 1 test:
  1 blackbox (output validated against expected_output.txt)

Executing 1 test...

✅ PASS error.e81007.good.tests::GreetingOnce [BlackBox] (nms)

Summary: 1 passed, 0 failed (1 total)
Types: 1 blackbox
Duration: nms

Questions and answers

These Q&A entries show E81007 and its fix:

• Q804: Why does EK9 have a built-in test framework instead of using JUnit or pytest?
• Q809: How does EK9 enforce test quality at compile time?