No tests were found that can be run. Please add tests and…

Error message

No tests were found that can be run. Please add tests and try again.

What it means

`baml-cli optimize` optimizes BAML functions by evaluating their test cases. Before the first optimization cycle it checks orchestrator.num_tests(); if zero tests exist there is nothing to evaluate, so it bails with this message. The first cycle needs at least 2 * num_tests evaluations, hence the guard.

Solutions

Add at least one `test { ... }` block to the BAML function you want to optimize.
Check your --from / baml_src path points at the directory containing the tests.
Remove any test-name filters/selectors that exclude all tests.
Run `baml-cli test` first to confirm tests are discoverable and passing.

Example fix

// before (no tests)
function ExtractResume(text: string) -> Resume { ... }
// after
test ExtractResumeTest {
  functions: [ExtractResume]
  args: { text: "John Doe, Software Engineer" }
}

Defensive patterns

Strategy: validation

Validate before calling

# ensure tests exist before optimizing
grep -r '^test ' baml_src/ >/dev/null || { echo 'add test blocks first'; exit 1; }

Try / catch

catch (e) {
  if (String(e.message).includes('No tests were found')) {
    // surface guidance: add test blocks to your BAML functions
  }
}

Prevention

Write test blocks for every function you plan to optimize.
Run `baml-cli test` first to confirm tests resolve.
Double-check --from and any test filters before optimize.

When it happens

Trigger: Running `baml-cli optimize` when the optimization run resolves to zero runnable tests — empty or missing test blocks in the targeted baml files, or a --from/selection that filters out all tests.

Common situations: Optimizing a project whose .baml files have functions but no `test` blocks, wrong baml_src path, tests filtered by name/pattern that matched nothing, using optimize before writing any tests.

Understand the failure class

Background: EmptyResultError / "no results found": when an API or scraper succeeds but returns zero rows — this error's family across 9 libraries.

Related errors

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/e697192b910f01a8. Report an issue: GitHub.

Appendix: source

Thrown at engine/baml-runtime/src/cli/optimize.rs:389

                function_filter: self.function.clone(),
                test_filter,
                trials,
                max_evals: self.max_evals,
                parallel: self.parallel,
                objectives,
                verbose: self.verbose,
                quiet: !self.no_ui, // Suppress output when TUI is active
                env_vars,
                baml_src_path: from.clone(),
                feature_flags,
            },
        )?;

        // Getting through the first optimization cycle requires at least `2 * num_tests` evaluations:
        // one pass for the initial candidate and another for the first improved candidate.
        let num_tests = orchestrator.num_tests();
        if num_tests == 0 {
            anyhow::bail!(
                "\n{} No tests were found that can be run. Please add tests and try again.",
                "error:".red().bold()
            );
        }

        let min_evals_for_one_cycle = 2 * num_tests;
        if self.max_evals < min_evals_for_one_cycle {
            eprintln!(
                "\n{} --max-evals ({}) is insufficient to run even a single optimization cycle.",
                "error:".red().bold(),
                self.max_evals.to_string().bold()
            );
            eprintln!(
                "  Increase {} to at least {} and try again {}",
                "--max-evals".bold(),
                min_evals_for_one_cycle.to_string().bold(),
                format!(
                    "(Initial evaluation ({num_tests}) + first trial ({num_tests}) = {})",

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