A specialized test runner for predictive functions, focusing on scenarios where 100% accuracy isn't expected or practical. Similar to Jest, vitest, or ava, but designed specifically for testing search, auto-complete, ML models, and statistical functions.
✅ Perfect for:
- Large test suites comparing input/output pairs
- Statistical/ML model testing where perfect accuracy isn't possible
- Testing flaky legacy systems
❌ Not recommended for:
- Small, example-based test suites (use Jest/vitest instead)
- Tests requiring advanced mocking or spy functionality
- Library-based: Unlike Jest/vitest, tots is imported as a library rather than used as a standalone runtime
- Effect-based: Requires effect as a dependency - your tested functions must return an Effect
⚠️ Note: This library is in alpha. Expect frequent breaking changes without warning. A beta phase with migration guidance is planned.
Install the required packages with your preferred package manager:
@creative-introvert/tons-of-tests
@creative-introvert/tons-of-tests-cli
effectDefine your test suite:
// my-test-suite.ts
import * as CLI from '@creative-introvert/tons-of-tests-cli';
import {Effect} from 'effect';
const myFunction = (input: number) => Promise.resolve(input * 1.7);
void CLI.run({
testSuite: {
name: 'with-cli-simple',
testCases: [
{input: 0, expected: 0},
{input: 1, expected: 2},
{input: 2, expected: 3},
{input: 3, expected: 4},
{input: 4, expected: 5},
],
program: (input: number) => Effect.promise(() => myFunction(input)),
},
dbPath: 'with-cli-simple.db',
concurrency: 10,
});pnpx tsx my-test-suite.ts summarize
┌───────────────────────────────────────────────────────────────────────────┐
│ SUMMARY │
├─────┬──────────┬────────┬──────┬───────┬──────────┬────────┬──────────────┤
│ #/∑ │ hash │ ms │ tags │ input │ expected │ label₀ │ diff result₀ │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┤
│ 1/5 │ bd04cb2c │ 0.69ms │ │ 0 │ 0 │ TP │ │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┤
│ 2/5 │ 562e2cca │ 0.36ms │ │ 1 │ 2 │ FP │ 2 => 1.7 │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┤
│ 3/5 │ a5afd52f │ 3.30ms │ │ 2 │ 3 │ FP │ 3 => 3.4 │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┤
│ 4/5 │ 5f7f8725 │ 1.19ms │ │ 3 │ 4 │ FP │ 4 => 5.1 │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┤
│ 5/5 │ 6cc26923 │ 1.22ms │ │ 4 │ 5 │ FP │ 5 => 6.8 │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┤
│ #/∑ │ hash │ ms │ tags │ input │ expected │ label₀ │ diff result₀ │
└─────┴──────────┴────────┴──────┴───────┴──────────┴────────┴──────────────┘
┌────────────────────────────────────────────────────────────────────┐
│ STATS │
├───┬────┬────┬────┬────┬───────────┬────────┬──────────┬────────────┤
│ ∑ │ TP │ TN │ FP │ FN │ precision │ recall │ timeMean │ timeMedian │
├───┼────┼────┼────┼────┼───────────┼────────┼──────────┼────────────┤
│ 5 │ 1 │ 0 │ 4 │ 0 │ 0.20 │ 1.00 │ 1.35ms │ 1.19ms │
├───┼────┼────┼────┼────┼───────────┼────────┼──────────┼────────────┤
│ ∑ │ TP │ TN │ FP │ FN │ precision │ recall │ timeMean │ timeMedian │
└───┴────┴────┴────┴────┴───────────┴────────┴──────────┴────────────┘
pnpx tsx my-test-suite.ts summarize --labels TP
┌───────────────────────────────────────────────────────────────────────────┐
│ SUMMARY │
├─────┬──────────┬────────┬──────┬───────┬──────────┬────────┬──────────────┤
│ #/∑ │ hash │ ms │ tags │ input │ expected │ label₀ │ diff result₀ │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┤
│ 1/1 │ bd04cb2c │ 0.52ms │ │ 0 │ 0 │ TP │ │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┤
│ #/∑ │ hash │ ms │ tags │ input │ expected │ label₀ │ diff result₀ │
└─────┴──────────┴────────┴──────┴───────┴──────────┴────────┴──────────────┘
┌────────────────────────────────────────────────────────────────────┐
│ STATS │
├───┬────┬────┬────┬────┬───────────┬────────┬──────────┬────────────┤
│ ∑ │ TP │ TN │ FP │ FN │ precision │ recall │ timeMean │ timeMedian │
├───┼────┼────┼────┼────┼───────────┼────────┼──────────┼────────────┤
│ 5 │ 1 │ 0 │ 4 │ 0 │ 0.20 │ 1.00 │ 1.23ms │ 1.28ms │
├───┼────┼────┼────┼────┼───────────┼────────┼──────────┼────────────┤
│ ∑ │ TP │ TN │ FP │ FN │ precision │ recall │ timeMean │ timeMedian │
└───┴────┴────┴────┴────┴───────────┴────────┴──────────┴────────────┘
pnpx tsx my-test-suite.ts commitThe diff command compares your current test results with previously committed results. This is useful when you've made changes to either:
- Your test suite's inputs or expected values
- The implementation of the function being tested
diff --git a/my-test-suite.ts b/my-test-suite.ts
index 21cd713..ab1b6dc 100644
--- a/my-test-suite.ts
+++ b/my-test-suite.ts
@@ -1,7 +1,7 @@
import * as CLI from '@creative-introvert/tots-cli';
import {Effect} from 'effect';
-const myFunction = (input: number) => Promise.resolve(input * 1.7);
+const myFunction = (input: number) => Promise.resolve(input * 2);
void CLI.run({
testSuite: {pnpx tsx my-test-suite.ts diff
# or, if you want it to process.exit(1) on diff
pnpx tsx my-test-suite.ts diff --exit-on-diff
┌─────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ SUMMARY │
├─────┬──────────┬────────┬──────┬───────┬──────────┬────────┬──────────────┬─────────┬───────────────┤
│ #/∑ │ hash │ ms │ tags │ input │ expected │ label₀ │ diff result₀ │ label₋₁ │ diff result₋₁ │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┼─────────┼───────────────┤
│ 1/4 │ 562e2cca │ 0.23ms │ │ 1 │ 2 │ TP │ │ FP │ 2 => 1.7 │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┼─────────┼───────────────┤
│ 2/4 │ a5afd52f │ 3.66ms │ │ 2 │ 3 │ FP │ 3 => 4 │ FP │ 3 => 3.4 │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┼─────────┼───────────────┤
│ 3/4 │ 5f7f8725 │ 1.19ms │ │ 3 │ 4 │ FP │ 4 => 6 │ FP │ 4 => 5.1 │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┼─────────┼───────────────┤
│ 4/4 │ 6cc26923 │ 0.98ms │ │ 4 │ 5 │ FP │ 5 => 8 │ FP │ 5 => 6.8 │
├─────┼──────────┼────────┼──────┼───────┼──────────┼────────┼──────────────┼─────────┼───────────────┤
│ #/∑ │ hash │ ms │ tags │ input │ expected │ label₀ │ diff result₀ │ label₋₁ │ diff result₋₁ │
└─────┴──────────┴────────┴──────┴───────┴──────────┴────────┴──────────────┴─────────┴───────────────┘
┌────────────────────────────────────────────────────────────────────┐
│ STATS │
├───┬────┬────┬────┬────┬───────────┬────────┬──────────┬────────────┤
│ ∑ │ TP │ TN │ FP │ FN │ precision │ recall │ timeMean │ timeMedian │
├───┼────┼────┼────┼────┼───────────┼────────┼──────────┼────────────┤
│ 5 │ 2 │ 0 │ 3 │ 0 │ 0.40 │ 1.00 │ 1.30ms │ 0.98ms │
├───┼────┼────┼────┼────┼───────────┼────────┼──────────┼────────────┤
│ ∑ │ TP │ TN │ FP │ FN │ precision │ recall │ timeMean │ timeMedian │
└───┴────┴────┴────┴────┴───────────┴────────┴──────────┴────────────┘
┌────────────────────────────────────────┐
│ DIFF │
├────┬────┬────┬────┬───────────┬────────┤
│ TP │ TN │ FP │ FN │ precision │ recall │
├────┼────┼────┼────┼───────────┼────────┤
│ 1 │ 0 │ -1 │ 0 │ 0.20 │ 0.00 │
├────┼────┼────┼────┼───────────┼────────┤
│ TP │ TN │ FP │ FN │ precision │ recall │
└────┴────┴────┴────┴───────────┴────────┘
Checkout workspace/examples/src/with-cli for more examples.
pnpx tsx <file-path>
# e.g.
pnpx tsx ./workspace/examples/src/with-cli/simple.ts
Checkout workspace/examples for more examples.
pnpx tsx <file-path>
# e.g.
pnpx tsx ./workspace/examples/src/with-cli/simple.tsMost test runners like Jest and Vitest come with their own command-line interface (CLI). When you run jest or vitest, these tools automatically find your test files, execute them, and report results.
While convenient, this approach introduces significant complexity:
-
Build System Complexity: Modern JavaScript/TypeScript projects use various build tools and configurations. A test runner needs complex logic to handle:
- TypeScript compilation with different configurations
- Module systems (ESM vs CommonJS)
- Framework-specific code (React, Svelte, etc.)
- Custom babel/esbuild/swc configurations
-
Framework vs Library Trade-offs: Test runners like Jest are frameworks - they control the execution flow and call your code. This means:
- The framework needs to provide many configuration options
- Customization requires understanding framework internals
- Extensions must fit within the framework's constraints
While we could integrate with existing test runners like Vitest, this would still impose their limitations and complexity.
Instead, tots is designed as a library that you import and use directly in your code. While this means writing a bit more boilerplate, it offers:
- Simpler implementation with fewer moving parts
- Full control over test execution
- Easy integration with your existing build tools
- Unlimited extensibility through normal JavaScript/TypeScript code