Add comprehensive test system for Go-to-Zig compiler

- Implement end-to-end test runner for compilation and behavior tests
- Add test cases for basic print functionality
- Refactor translator to use proper AST generation
- Remove redundant programs directory in favor of tests

cmd/testrunner/main.go

@@ -0,0 +1,228 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+)
+
+type TestResult struct {
+	Name    string
+	Passed  bool
+	Output  string
+	Error   string
+	Elapsed time.Duration
+}
+
+type TestCase struct {
+	GoFile       string
+	ExpectedFile string
+	ErrorFile    string
+	StdinFile    string
+	ArgsFile     string
+}
+
+func main() {
+	// Find all test cases
+	testCases, err := findTestCases("tests")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error finding tests: %v\n", err)
+		os.Exit(1)
+	}
+
+	if len(testCases) == 0 {
+		fmt.Println("No tests found")
+		os.Exit(0)
+	}
+
+	fmt.Printf("Running %d tests...\n\n", len(testCases))
+
+	// Run tests in parallel
+	results := runTests(testCases)
+
+	// Print results
+	passed := 0
+	failed := 0
+	for _, result := range results {
+		if result.Passed {
+			fmt.Printf("✓ %s (%v)\n", result.Name, result.Elapsed)
+			passed++
+		} else {
+			fmt.Printf("✗ %s (%v)\n", result.Name, result.Elapsed)
+			fmt.Printf("  Error: %s\n", result.Error)
+			if result.Output != "" {
+				fmt.Printf("  Output:\n%s\n", indent(result.Output, "    "))
+			}
+			failed++
+		}
+	}
+
+	fmt.Printf("\n%d passed, %d failed\n", passed, failed)
+
+	if failed > 0 {
+		os.Exit(1)
+	}
+}
+
+func findTestCases(dir string) ([]TestCase, error) {
+	var testCases []TestCase
+
+	err := filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if strings.HasSuffix(path, ".go") {
+			base := strings.TrimSuffix(path, ".go")
+			testCase := TestCase{
+				GoFile:       path,
+				ExpectedFile: base + ".expected",
+				ErrorFile:    base + ".error",
+				StdinFile:    base + ".stdin",
+				ArgsFile:     base + ".args",
+			}
+
+			// Check if either .expected or .error exists
+			if fileExists(testCase.ExpectedFile) || fileExists(testCase.ErrorFile) {
+				testCases = append(testCases, testCase)
+			}
+		}
+
+		return nil
+	})
+
+	return testCases, err
+}
+
+func runTests(testCases []TestCase) []TestResult {
+	results := make([]TestResult, len(testCases))
+	var wg sync.WaitGroup
+
+	for i, tc := range testCases {
+		wg.Add(1)
+		go func(idx int, testCase TestCase) {
+			defer wg.Done()
+			results[idx] = runTest(testCase)
+		}(i, tc)
+	}
+
+	wg.Wait()
+	return results
+}
+
+func runTest(tc TestCase) TestResult {
+	start := time.Now()
+	testName := filepath.Base(strings.TrimSuffix(tc.GoFile, ".go"))
+	
+	result := TestResult{
+		Name:    testName,
+		Elapsed: time.Since(start),
+	}
+
+	// Create temporary directory for test outputs
+	tempDir, err := os.MkdirTemp("", "go-zig-test-*")
+	if err != nil {
+		result.Error = fmt.Sprintf("Failed to create temp dir: %v", err)
+		return result
+	}
+	defer os.RemoveAll(tempDir)
+
+	zigFile := filepath.Join(tempDir, testName+".zig")
+
+	// Compile Go to Zig
+	compileCmd := exec.Command("go", "run", "./internal/main.go", "-o", zigFile, tc.GoFile)
+	var compileOut bytes.Buffer
+	compileCmd.Stderr = &compileOut
+	compileCmd.Stdout = &compileOut
+
+	if err := compileCmd.Run(); err != nil {
+		// Check if this is an expected compilation error
+		if fileExists(tc.ErrorFile) {
+			expectedError, _ := os.ReadFile(tc.ErrorFile)
+			actualError := strings.TrimSpace(compileOut.String())
+			expectedErrorStr := strings.TrimSpace(string(expectedError))
+			
+			if actualError == expectedErrorStr {
+				result.Passed = true
+			} else {
+				result.Error = fmt.Sprintf("Expected error:\n%s\n\nActual error:\n%s", expectedErrorStr, actualError)
+			}
+		} else {
+			result.Error = fmt.Sprintf("Compilation failed: %v\nOutput: %s", err, compileOut.String())
+		}
+		result.Elapsed = time.Since(start)
+		return result
+	}
+
+	// If we expected a compilation error but didn't get one
+	if fileExists(tc.ErrorFile) {
+		result.Error = "Expected compilation to fail, but it succeeded"
+		result.Elapsed = time.Since(start)
+		return result
+	}
+
+	// Run the Zig program
+	runCmd := exec.Command("zig", "run", zigFile)
+	
+	// Set up stdin if provided
+	if fileExists(tc.StdinFile) {
+		stdinData, _ := os.ReadFile(tc.StdinFile)
+		runCmd.Stdin = bytes.NewReader(stdinData)
+	}
+
+	// Set up args if provided
+	if fileExists(tc.ArgsFile) {
+		argsData, _ := os.ReadFile(tc.ArgsFile)
+		args := strings.Fields(string(argsData))
+		runCmd.Args = append(runCmd.Args, args...)
+	}
+
+	// Capture both stdout and stderr (Zig's debug.print goes to stderr)
+	output, err := runCmd.CombinedOutput()
+	if err != nil {
+		result.Error = fmt.Sprintf("Execution failed: %v\nOutput: %s", err, string(output))
+		result.Output = string(output)
+		result.Elapsed = time.Since(start)
+		return result
+	}
+
+	// Compare output with expected
+	if fileExists(tc.ExpectedFile) {
+		expectedOutput, _ := os.ReadFile(tc.ExpectedFile)
+		actualOutput := string(output)
+		
+		if actualOutput == string(expectedOutput) {
+			result.Passed = true
+		} else {
+			result.Error = fmt.Sprintf("Output mismatch.\nExpected:\n%s\nActual:\n%s", 
+				string(expectedOutput), actualOutput)
+			result.Output = actualOutput
+		}
+	} else {
+		// No expected file, just check it runs without error
+		result.Passed = true
+	}
+
+	result.Elapsed = time.Since(start)
+	return result
+}
+
+func fileExists(path string) bool {
+	_, err := os.Stat(path)
+	return err == nil
+}
+
+func indent(s string, prefix string) string {
+	lines := strings.Split(s, "\n")
+	for i, line := range lines {
+		if line != "" {
+			lines[i] = prefix + line
+		}
+	}
+	return strings.Join(lines, "\n")
+}