lambda/cmd/lambda/lambda_test.go

package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"git.maximhutz.com/max/lambda/pkg/convert"
	"git.maximhutz.com/max/lambda/pkg/debruijn"
	"git.maximhutz.com/max/lambda/pkg/lambda"
	"git.maximhutz.com/max/lambda/pkg/saccharine"
	"github.com/stretchr/testify/assert"
)

// Helper function to run a single sample through the lambda interpreter.
func runSample(samplePath string) (string, error) {
	// Read the sample file.
	input, err := os.ReadFile(samplePath)
	if err != nil {
		return "", err
	}

	// Parse code into syntax tree.
	ast, err := saccharine.Parse(string(input))
	if err != nil {
		return "", err
	}

	// Compile expression to lambda calculus.
	compiled := convert.SaccharineToLambda(ast)

	// Create and run the reducer.
	reducer := lambda.NewNormalOrderReducer(&compiled)
	reducer.Reduce()

	return reducer.Expression().String() + "\n", nil
}

// Helper function to run a single sample through the De Bruijn interpreter.
func runSampleDeBruijn(samplePath string) (string, error) {
	// Read the sample file.
	input, err := os.ReadFile(samplePath)
	if err != nil {
		return "", err
	}

	// Parse code into syntax tree.
	ast, err := saccharine.Parse(string(input))
	if err != nil {
		return "", err
	}

	// Compile expression to lambda calculus.
	compiled := convert.SaccharineToLambda(ast)

	// Convert to De Bruijn and run reducer.
	dbExpr := convert.LambdaToDeBruijn(compiled)
	reducer := debruijn.NewNormalOrderReducer(&dbExpr)
	reducer.Reduce()

	// Convert back to lambda for output.
	result := reducer.Expression().(debruijn.Expression)
	lambdaResult := convert.DeBruijnToLambda(result)

	return lambdaResult.String() + "\n", nil
}

// Test that all samples produce expected output with lambda interpreter.
func TestSamplesValidity(t *testing.T) {
	// Discover all .test files in the tests directory.
	testFiles, err := filepath.Glob("../../tests/*.test")
	assert.NoError(t, err, "Failed to read tests directory.")
	assert.NotEmpty(t, testFiles, "No '*.test' files found in directory.")

	for _, testPath := range testFiles {
		// Build expected file path.
		expectedPath := strings.TrimSuffix(testPath, filepath.Ext(testPath)) + ".expected"

		name := strings.TrimSuffix(filepath.Base(testPath), filepath.Ext(testPath))

		t.Run(name, func(t *testing.T) {
			// Run the sample and capture output.
			actual, err := runSample(testPath)
			assert.NoError(t, err, "Failed to run sample.")

			// Read expected output.
			expectedBytes, err := os.ReadFile(expectedPath)
			assert.NoError(t, err, "Failed to read expected output.")
			expected := string(expectedBytes)

			// Compare outputs.
			assert.Equal(t, expected, actual, "Output does not match expected.")
		})
	}
}

// Test that all samples produce expected output with De Bruijn interpreter.
func TestSamplesValidityDeBruijn(t *testing.T) {
	// Discover all .test files in the tests directory.
	testFiles, err := filepath.Glob("../../tests/*.test")
	assert.NoError(t, err, "Failed to read tests directory.")
	assert.NotEmpty(t, testFiles, "No '*.test' files found in directory.")

	for _, testPath := range testFiles {
		// Build expected file path.
		expectedPath := strings.TrimSuffix(testPath, filepath.Ext(testPath)) + ".expected"

		name := strings.TrimSuffix(filepath.Base(testPath), filepath.Ext(testPath))

		t.Run(name, func(t *testing.T) {
			// Run the sample and capture output.
			actual, err := runSampleDeBruijn(testPath)
			assert.NoError(t, err, "Failed to run sample.")

			// Read expected output.
			expectedBytes, err := os.ReadFile(expectedPath)
			assert.NoError(t, err, "Failed to read expected output.")
			expected := string(expectedBytes)

			// Compare outputs.
			assert.Equal(t, expected, actual, "Output does not match expected.")
		})
	}
}

// Benchmark all samples using sub-benchmarks.
func BenchmarkSamples(b *testing.B) {
	// Discover all .test files in the tests directory.
	testFiles, err := filepath.Glob("../../tests/*.test")
	assert.NoError(b, err, "Failed to read tests directory.")
	assert.NotEmpty(b, testFiles, "No '*.test' files found in directory.")

	for _, path := range testFiles {
		name := strings.TrimSuffix(filepath.Base(path), filepath.Ext(path))

		b.Run(name, func(b *testing.B) {
			for b.Loop() {
				_, err := runSample(path)
				assert.NoError(b, err, "Failed to run sample.")
			}
		})
	}
}

// Benchmark all samples using De Bruijn interpreter.
func BenchmarkSamplesDeBruijn(b *testing.B) {
	// Discover all .test files in the tests directory.
	testFiles, err := filepath.Glob("../../tests/*.test")
	assert.NoError(b, err, "Failed to read tests directory.")
	assert.NotEmpty(b, testFiles, "No '*.test' files found in directory.")

	for _, path := range testFiles {
		name := strings.TrimSuffix(filepath.Base(path), filepath.Ext(path))

		b.Run(name, func(b *testing.B) {
			for b.Loop() {
				_, err := runSampleDeBruijn(path)
				assert.NoError(b, err, "Failed to run sample.")
			}
		})
	}
}