Merge pull request #40 from DATA-DOG/build-tools

Revisit godog suite compilation and build tools to support vendoring

.travis.yml

@@ -1,6 +1,5 @@
 language: go
 go:
-  - 1.4
   - 1.5
   - 1.6
   - tip

README.md

@@ -24,13 +24,9 @@ behavior. You can leverage both frameworks to functionally test your
 application while maintaining all test related source code in **_test.go**
 files.
 
-**Godog** acts similar compared to **go test** command. It uses
+**Godog** acts similar compared to **go test** command. It uses go
-a **TestMain** hook introduced in `go1.4` and clones the package sources
+compiler and linker tool in order to produce test executable. Godog
-to a temporary build directory. The only change it does is adding a runner
+contexts needs to be exported same as Test functions for go test.
-test.go file additionally and ensures to cleanup TestMain func if it was
-used in tests. **Godog** uses standard **go** ast and build utils to
-generate test suite package and even builds it with **go test -c**
-command. It even passes all your environment exported vars.
 
 **Godog** ships gherkin parser dependency as a subpackage. This will
 ensure that it is always compatible with the installed version of godog.
@@ -111,7 +107,7 @@ Since we need a working implementation, we may start by implementing only what i
 
 #### Step 3
 
-We only need a number of **godogs** for now. Let's define steps.
+We only need a number of **godogs** for now. Lets keep it simple.
 
 ``` go
 /* file: examples/godogs/godog.go */
@@ -125,7 +121,8 @@ func main() { /* usual main func */ }
 
 #### Step 4
 
-Now let's finish our step implementations in order to test our feature requirements:
+Now lets implement our step definitions, which we can copy from generated
+console output snippets in order to test our feature requirements:
 
 ``` go
 /* file: examples/godogs/godog_test.go */
@@ -157,7 +154,7 @@ func thereShouldBeRemaining(remaining int) error {
 	return nil
 }
 
-func featureContext(s *godog.Suite) {
+func FeatureContext(s *godog.Suite) {
 	s.Step(`^there are (\d+) godogs$`, thereAreGodogs)
 	s.Step(`^I eat (\d+)$`, iEat)
 	s.Step(`^there should be (\d+) remaining$`, thereShouldBeRemaining)
@@ -193,6 +190,12 @@ See implementation examples:
 
 ### Changes
 
+**2016-06-14**
+- godog now uses **go tool compile** and **go tool link** to support
+  vendor directory dependencies. It also compiles test executable the same
+  way as standard **go test** utility. With this change, only go
+  versions from **1.5** are now supported.
+
 **2016-06-01**
 - parse flags in main command, to show version and help without needing
   to compile test package and buildable go sources.

ast.go

@@ -1,12 +1,6 @@
 package godog
 
-import (
+import "go/ast"
-	"go/ast"
-	"go/build"
-	"go/token"
-	"path"
-	"strings"
-)
 
 func astContexts(f *ast.File) []string {
 	var contexts []string
@@ -35,103 +29,3 @@ func astContexts(f *ast.File) []string {
 	}
 	return contexts
 }
-
-func astRemoveUnusedImports(f *ast.File) {
-	used := astUsedPackages(f)
-	isUsed := func(p string) bool {
-		for _, ref := range used {
-			if p == ref {
-				return true
-			}
-		}
-		return p == "_"
-	}
-	var decls []ast.Decl
-	for _, d := range f.Decls {
-		gen, ok := d.(*ast.GenDecl)
-		if ok && gen.Tok == token.IMPORT {
-			var specs []ast.Spec
-			for _, spec := range gen.Specs {
-				impspec := spec.(*ast.ImportSpec)
-				ipath := strings.Trim(impspec.Path.Value, `\"`)
-				check := astImportPathToName(ipath)
-				if impspec.Name != nil {
-					check = impspec.Name.Name
-				}
-
-				if isUsed(check) {
-					specs = append(specs, spec)
-				}
-			}
-
-			if len(specs) == 0 {
-				continue
-			}
-			gen.Specs = specs
-		}
-		decls = append(decls, d)
-	}
-	f.Decls = decls
-}
-
-func astDeleteTestMainFunc(f *ast.File) {
-	var decls []ast.Decl
-	var hadTestMain bool
-	for _, d := range f.Decls {
-		fun, ok := d.(*ast.FuncDecl)
-		if !ok {
-			decls = append(decls, d)
-			continue
-		}
-		if fun.Name.Name != "TestMain" {
-			decls = append(decls, fun)
-		} else {
-			hadTestMain = true
-		}
-	}
-	f.Decls = decls
-
-	if hadTestMain {
-		astRemoveUnusedImports(f)
-	}
-}
-
-type visitFn func(node ast.Node) ast.Visitor
-
-func (fn visitFn) Visit(node ast.Node) ast.Visitor {
-	return fn(node)
-}
-
-func astUsedPackages(f *ast.File) []string {
-	var refs []string
-	var visitor visitFn
-	visitor = visitFn(func(node ast.Node) ast.Visitor {
-		if node == nil {
-			return visitor
-		}
-		switch v := node.(type) {
-		case *ast.SelectorExpr:
-			xident, ok := v.X.(*ast.Ident)
-			if !ok {
-				break
-			}
-			if xident.Obj != nil {
-				// if the parser can resolve it, it's not a package ref
-				break
-			}
-			refs = append(refs, xident.Name)
-		}
-		return visitor
-	})
-	ast.Walk(visitor, f)
-	return refs
-}
-
-// importPathToName finds out the actual package name, as declared in its .go files.
-// If there's a problem, it falls back to using importPathToNameBasic.
-func astImportPathToName(importPath string) (packageName string) {
-	if buildPkg, err := build.Import(importPath, "", 0); err == nil {
-		return buildPkg.Name
-	}
-	return path.Base(importPath)
-}

ast_context_test.go

@@ -1,76 +0,0 @@
-package godog
-
-import (
-	"go/parser"
-	"go/token"
-	"testing"
-)
-
-var astContextSrc = `package main
-
-import (
-	"github.com/DATA-DOG/godog"
-)
-
-func myContext(s *godog.Suite) {
-}`
-
-var astTwoContextSrc = `package lib
-
-import (
-	"github.com/DATA-DOG/godog"
-)
-
-func apiContext(s *godog.Suite) {
-}
-
-func dbContext(s *godog.Suite) {
-}`
-
-func astContextParse(src string, t *testing.T) []string {
-	fset := token.NewFileSet()
-	f, err := parser.ParseFile(fset, "", []byte(src), 0)
-	if err != nil {
-		t.Fatalf("unexpected error while parsing ast: %v", err)
-	}
-
-	return astContexts(f)
-}
-
-func TestShouldGetSingleContextFromSource(t *testing.T) {
-	actual := astContextParse(astContextSrc, t)
-	expect := []string{"myContext"}
-
-	if len(actual) != len(expect) {
-		t.Fatalf("number of found contexts do not match, expected %d, but got %d", len(expect), len(actual))
-	}
-
-	for i, c := range expect {
-		if c != actual[i] {
-			t.Fatalf("expected context '%s' at pos %d, but got: '%s'", c, i, actual[i])
-		}
-	}
-}
-
-func TestShouldGetTwoContextsFromSource(t *testing.T) {
-	actual := astContextParse(astTwoContextSrc, t)
-	expect := []string{"apiContext", "dbContext"}
-
-	if len(actual) != len(expect) {
-		t.Fatalf("number of found contexts do not match, expected %d, but got %d", len(expect), len(actual))
-	}
-
-	for i, c := range expect {
-		if c != actual[i] {
-			t.Fatalf("expected context '%s' at pos %d, but got: '%s'", c, i, actual[i])
-		}
-	}
-}
-
-func TestShouldNotFindAnyContextsInEmptyFile(t *testing.T) {
-	actual := astContextParse(`package main`, t)
-
-	if len(actual) != 0 {
-		t.Fatalf("expected no contexts to be found, but there was some: %v", actual)
-	}
-}

ast_test.go

@@ -1,162 +1,76 @@
 package godog
 
 import (
-	"bytes"
-	"go/format"
 	"go/parser"
 	"go/token"
-	"strings"
 	"testing"
 )
 
-var astMainFile = `package main
+var astContextSrc = `package main
-
-import "fmt"
-
-func main() {
-	fmt.Println("hello")
-}`
-
-var astNormalFile = `package main
-
-import "fmt"
-
-func hello() {
-	fmt.Println("hello")
-}`
-
-var astTestMainFile = `package main
 
 import (
-	"fmt"
+	"github.com/DATA-DOG/godog"
-	"testing"
-	"os"
 )
 
-func TestMain(m *testing.M) {
+func MyContext(s *godog.Suite) {
-	fmt.Println("hello")
-	os.Exit(0)
 }`
 
-var astPackAliases = `package main
+var astTwoContextSrc = `package lib
 
 import (
-	"testing"
+	"github.com/DATA-DOG/godog"
-	a "fmt"
-	b "fmt"
 )
 
-func TestMain(m *testing.M) {
+func ApiContext(s *godog.Suite) {
-	a.Println("a")
+}
-	b.Println("b")
+
+func DBContext(s *godog.Suite) {
 }`
 
-var astAnonymousImport = `package main
+func astContextParse(src string, t *testing.T) []string {
-
-import (
-	"testing"
-	_ "github.com/go-sql-driver/mysql"
-)
-
-func TestMain(m *testing.M) {
-}`
-
-var astLibrarySrc = `package lib
-
-import "fmt"
-
-func test() {
-	fmt.Println("hello")
-}`
-
-var astInternalPackageSrc = `package godog
-
-import "fmt"
-
-func test() {
-	fmt.Println("hello")
-}`
-
-func astProcess(src string, t *testing.T) string {
 	fset := token.NewFileSet()
 	f, err := parser.ParseFile(fset, "", []byte(src), 0)
 	if err != nil {
 		t.Fatalf("unexpected error while parsing ast: %v", err)
 	}
 
-	astDeleteTestMainFunc(f)
+	return astContexts(f)
-
-	var buf bytes.Buffer
-	if err := format.Node(&buf, fset, f); err != nil {
-		t.Fatalf("failed to build source file: %v", err)
-	}
-
-	return buf.String()
 }
 
-func TestShouldCleanTestMainFromSimpleTestFile(t *testing.T) {
+func TestShouldGetSingleContextFromSource(t *testing.T) {
-	actual := strings.TrimSpace(astProcess(astTestMainFile, t))
+	actual := astContextParse(astContextSrc, t)
-	expect := `package main`
+	expect := []string{"MyContext"}
 
-	if actual != expect {
+	if len(actual) != len(expect) {
-		t.Fatalf("expected output does not match: %s", actual)
+		t.Fatalf("number of found contexts do not match, expected %d, but got %d", len(expect), len(actual))
+	}
+
+	for i, c := range expect {
+		if c != actual[i] {
+			t.Fatalf("expected context '%s' at pos %d, but got: '%s'", c, i, actual[i])
+		}
 	}
 }
 
-func TestShouldCleanTestMainFromFileWithPackageAliases(t *testing.T) {
+func TestShouldGetTwoContextsFromSource(t *testing.T) {
-	actual := strings.TrimSpace(astProcess(astPackAliases, t))
+	actual := astContextParse(astTwoContextSrc, t)
-	expect := `package main`
+	expect := []string{"ApiContext", "DBContext"}
 
-	if actual != expect {
+	if len(actual) != len(expect) {
-		t.Fatalf("expected output does not match: %s", actual)
+		t.Fatalf("number of found contexts do not match, expected %d, but got %d", len(expect), len(actual))
+	}
+
+	for i, c := range expect {
+		if c != actual[i] {
+			t.Fatalf("expected context '%s' at pos %d, but got: '%s'", c, i, actual[i])
+		}
 	}
 }
 
-func TestShouldNotModifyNormalFile(t *testing.T) {
+func TestShouldNotFindAnyContextsInEmptyFile(t *testing.T) {
-	actual := strings.TrimSpace(astProcess(astNormalFile, t))
+	actual := astContextParse(`package main`, t)
-	expect := astNormalFile
 
-	if actual != expect {
+	if len(actual) != 0 {
-		t.Fatalf("expected output does not match: %s", actual)
+		t.Fatalf("expected no contexts to be found, but there was some: %v", actual)
-	}
-}
-
-func TestShouldNotModifyMainFile(t *testing.T) {
-	actual := strings.TrimSpace(astProcess(astMainFile, t))
-	expect := astMainFile
-
-	if actual != expect {
-		t.Fatalf("expected output does not match: %s", actual)
-	}
-}
-
-func TestShouldMaintainAnonymousImport(t *testing.T) {
-	actual := strings.TrimSpace(astProcess(astAnonymousImport, t))
-	expect := `package main
-
-import (
-	_ "github.com/go-sql-driver/mysql"
-)`
-
-	if actual != expect {
-		t.Fatalf("expected output does not match: %s", actual)
-	}
-}
-
-func TestShouldNotModifyLibraryPackageSource(t *testing.T) {
-	actual := strings.TrimSpace(astProcess(astLibrarySrc, t))
-	expect := astLibrarySrc
-
-	if actual != expect {
-		t.Fatalf("expected output does not match: %s", actual)
-	}
-}
-
-func TestShouldNotModifyGodogPackageSource(t *testing.T) {
-	actual := strings.TrimSpace(astProcess(astInternalPackageSrc, t))
-	expect := astInternalPackageSrc
-
-	if actual != expect {
-		t.Fatalf("expected output does not match: %s", actual)
 	}
 }

builder.go

@@ -1,118 +1,268 @@
 package godog
 
 import (
+	"bytes"
+	"fmt"
 	"go/build"
-	"go/format"
 	"go/parser"
 	"go/token"
-	"io"
+	"io/ioutil"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"strings"
 	"text/template"
+	"time"
+	"unicode"
 )
 
-var runnerTemplate = template.Must(template.New("main").Parse(`package {{ .Name }}
+var compiler = filepath.Join(build.ToolDir, "compile")
+var linker = filepath.Join(build.ToolDir, "link")
+var gopaths = filepath.SplitList(build.Default.GOPATH)
+var goarch = build.Default.GOARCH
+var goos = build.Default.GOOS
+
+var godogImportPath = "github.com/DATA-DOG/godog"
+var runnerTemplate = template.Must(template.New("testmain").Parse(`package main
 
 import (
-	{{ if ne .Name "godog" }}"github.com/DATA-DOG/godog"{{ end }}
+	"github.com/DATA-DOG/godog"
+	{{if .Contexts}}_test "{{.ImportPath}}"{{end}}
 	"os"
-	"testing"
 )
 
-const GodogSuiteName = "{{ .Name }}"
+func main() {
-
+	status := godog.Run(func (suite *godog.Suite) {
-func TestMain(m *testing.M) {
-	status := {{ if ne .Name "godog" }}godog.{{ end }}Run(func (suite *{{ if ne .Name "godog" }}godog.{{ end }}Suite) {
 		{{range .Contexts}}
-			{{ . }}(suite)
+			_test.{{ . }}(suite)
 		{{end}}
 	})
 	os.Exit(status)
 }`))
 
-// Build scans clones current package into a temporary
+// Build creates a test package like go test command.
-// godog suite test package.
+// If there are no go files in tested directory, then
+// it simply builds a godog executable to scan features.
 //
-// If there is a TestMain func in any of test.go files
+// If there are go test files, it first builds a test
-// it removes it and all necessary unused imports related
+// package with standard go test command.
-// to this function.
 //
-// It also looks for any godog suite contexts and registers
+// Finally it generates godog suite executable which
-// them in order to call them on execution.
+// registers exported godog contexts from the test files
+// of tested package.
 //
-// The test entry point which uses go1.4 TestMain func
+// Returns the path to generated executable
-// is generated from the template above.
+func Build() (string, error) {
-func Build(dir string) error {
+	abs, err := filepath.Abs(".")
-	pkg, err := build.ImportDir(".", 0)
 	if err != nil {
-		return err
+		return "", err
 	}
 
-	return buildTestPackage(pkg, dir)
+	bin := filepath.Join(abs, "godog.test")
-}
+	// suffix with .exe for windows
-
+	if goos == "windows" {
-// buildTestPackage clones a package and adds a godog
+		bin += ".exe"
-// entry point with TestMain func in order to
-// run the test suite. If TestMain func is found in tested
-// source, it will be removed so it can be replaced
-func buildTestPackage(pkg *build.Package, dir string) error {
-	// these file packs may be adjusted in the future, if there are complaints
-	// in general, most important aspect is to replicate go test behavior
-	err := copyNonTestPackageFiles(
-		dir,
-		pkg.CFiles,
-		pkg.CgoFiles,
-		pkg.CXXFiles,
-		pkg.HFiles,
-		pkg.GoFiles,
-		pkg.IgnoredGoFiles,
-	)
-
-	if err != nil {
-		return err
 	}
 
-	contexts, err := processPackageTestFiles(
+	// we allow package to be nil, if godog is run only when
-		dir,
+	// there is a feature file in empty directory
-		pkg.TestGoFiles,
+	pkg, _ := build.ImportDir(abs, 0)
-		pkg.XTestGoFiles,
+	src, anyContexts, err := buildTestMain(pkg)
-	)
 	if err != nil {
-		return err
+		return bin, err
 	}
 
-	// build godog runner test file
+	workdir := fmt.Sprintf(filepath.Join("%s", "godog-%d"), os.TempDir(), time.Now().UnixNano())
-	out, err := os.Create(filepath.Join(dir, "godog_runner_test.go"))
+	testdir := workdir
-	if err != nil {
-		return err
-	}
-	defer out.Close()
 
-	data := struct {
+	// if none of test files exist, or there are no contexts found
-		Name     string
+	// we will skip test package compilation, since it is useless
-		Contexts []string
+	if anyContexts {
-	}{pkg.Name, contexts}
+		// first of all compile test package dependencies
+		// that will save was many compilations for dependencies
+		// go does it better
+		out, err := exec.Command("go", "test", "-i").CombinedOutput()
+		if err != nil {
+			return bin, fmt.Errorf("failed to compile package %s:\n%s", pkg.Name, string(out))
+		}
 
-	return runnerTemplate.Execute(out, data)
+		// let go do the dirty work and compile test
-}
+		// package with it's dependencies. Older go
+		// versions does not accept existing file output
+		// so we create a temporary executable which will
+		// removed.
+		temp := fmt.Sprintf(filepath.Join("%s", "temp-%d.test"), os.TempDir(), time.Now().UnixNano())
 
-// copyNonTestPackageFiles simply copies all given file packs
+		// builds and compile the tested package.
-// to the destDir.
+		// generated test executable will be removed
-func copyNonTestPackageFiles(destDir string, packs ...[]string) error {
+		// since we do not need it for godog suite.
-	for _, pack := range packs {
+		// we also print back the temp WORK directory
-		for _, file := range pack {
+		// go has built. We will reuse it for our suite workdir.
-			if err := copyPackageFile(file, filepath.Join(destDir, file)); err != nil {
+		out, err = exec.Command("go", "test", "-c", "-work", "-o", temp).CombinedOutput()
-				return err
+		if err != nil {
-			}
+			return bin, fmt.Errorf("failed to compile tested package %s:\n%s", pkg.Name, string(out))
+		}
+		defer os.Remove(temp)
+
+		// extract go-build temporary directory as our workdir
+		workdir = strings.TrimSpace(string(out))
+		if !strings.HasPrefix(workdir, "WORK=") {
+			return bin, fmt.Errorf("expected WORK dir path, but got: %s", workdir)
+		}
+		workdir = strings.Replace(workdir, "WORK=", "", 1)
+		testdir = filepath.Join(workdir, pkg.ImportPath, "_test")
+	} else {
+		// still need to create temporary workdir
+		if err = os.MkdirAll(testdir, 0755); err != nil {
+			return bin, err
 		}
 	}
-	return nil
+	defer os.RemoveAll(workdir)
+
+	// replace _testmain.go file with our own
+	testmain := filepath.Join(testdir, "_testmain.go")
+	err = ioutil.WriteFile(testmain, src, 0644)
+	if err != nil {
+		return bin, err
+	}
+
+	// godog library may not be imported in tested package
+	// but we need it for our testmain package.
+	// So we look it up in available source paths
+	// including vendor directory, supported since 1.5.
+	try := []string{filepath.Join(abs, "vendor", godogImportPath)}
+	for _, d := range build.Default.SrcDirs() {
+		try = append(try, filepath.Join(d, godogImportPath))
+	}
+	godogPkg, err := locatePackage(try)
+	if err != nil {
+		return bin, err
+	}
+
+	// make sure godog package archive is installed, gherkin
+	// will be installed as dependency of godog
+	cmd := exec.Command("go", "install", godogPkg.ImportPath)
+	cmd.Env = os.Environ()
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return bin, fmt.Errorf("failed to install godog package:\n%s", string(out))
+	}
+
+	// collect all possible package dirs, will be
+	// used for includes and linker
+	pkgDirs := []string{workdir, testdir}
+	for _, gopath := range gopaths {
+		pkgDirs = append(pkgDirs, filepath.Join(gopath, "pkg", goos+"_"+goarch))
+	}
+	pkgDirs = uniqStringList(pkgDirs)
+
+	// compile godog testmain package archive
+	// we do not depend on CGO so a lot of checks are not necessary
+	testMainPkgOut := filepath.Join(testdir, "main.a")
+	args := []string{
+		"-o", testMainPkgOut,
+		// "-trimpath", workdir,
+		"-p", "main",
+		"-complete",
+	}
+	// if godog library is in vendor directory
+	// link it with import map
+	if i := strings.LastIndex(godogPkg.ImportPath, "vendor/"); i != -1 {
+		args = append(args, "-importmap", godogImportPath+"="+godogPkg.ImportPath)
+	}
+	for _, inc := range pkgDirs {
+		args = append(args, "-I", inc)
+	}
+	args = append(args, "-pack", testmain)
+	cmd = exec.Command(compiler, args...)
+	cmd.Env = os.Environ()
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		return bin, fmt.Errorf("failed to compile testmain package:\n%s", string(out))
+	}
+
+	// link test suite executable
+	args = []string{
+		"-o", bin,
+		"-extld", build.Default.Compiler,
+		"-buildmode=exe",
+	}
+	for _, link := range pkgDirs {
+		args = append(args, "-L", link)
+	}
+	args = append(args, testMainPkgOut)
+	cmd = exec.Command(linker, args...)
+	cmd.Env = os.Environ()
+
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		return bin, fmt.Errorf("failed to link test executable:\n%s", string(out))
+	}
+
+	return bin, nil
+}
+
+func locatePackage(try []string) (*build.Package, error) {
+	for _, path := range try {
+		abs, err := filepath.Abs(path)
+		if err != nil {
+			continue
+		}
+		pkg, err := build.ImportDir(abs, 0)
+		if err != nil {
+			continue
+		}
+		return pkg, nil
+	}
+	return nil, fmt.Errorf("failed to find godog package in any of:\n%s", strings.Join(try, "\n"))
+}
+
+func uniqStringList(strs []string) (unique []string) {
+	uniq := make(map[string]void, len(strs))
+	for _, s := range strs {
+		if _, ok := uniq[s]; !ok {
+			uniq[s] = void{}
+			unique = append(unique, s)
+		}
+	}
+	return
+}
+
+// buildTestMain if given package is valid
+// it scans test files for contexts
+// and produces a testmain source code.
+func buildTestMain(pkg *build.Package) ([]byte, bool, error) {
+	var contexts []string
+	var importPath string
+	if nil != pkg {
+		ctxs, err := processPackageTestFiles(
+			pkg.TestGoFiles,
+			pkg.XTestGoFiles,
+		)
+		if err != nil {
+			return nil, false, err
+		}
+		contexts = ctxs
+		importPath = pkg.ImportPath
+	}
+
+	data := struct {
+		Name       string
+		Contexts   []string
+		ImportPath string
+	}{pkg.Name, contexts, importPath}
+
+	var buf bytes.Buffer
+	if err := runnerTemplate.Execute(&buf, data); err != nil {
+		return nil, len(contexts) > 0, err
+	}
+	return buf.Bytes(), len(contexts) > 0, nil
 }
 
 // processPackageTestFiles runs through ast of each test
-// file pack and removes TestMain func if found. it also
+// file pack and looks for godog suite contexts to register
-// looks for godog suite contexts to register on run
+// on run
-func processPackageTestFiles(destDir string, packs ...[]string) ([]string, error) {
+func processPackageTestFiles(packs ...[]string) ([]string, error) {
 	var ctxs []string
 	fset := token.NewFileSet()
 	for _, pack := range packs {
@@ -122,52 +272,19 @@ func processPackageTestFiles(destDir string, packs ...[]string) ([]string, error
 				return ctxs, err
 			}
 
-			astDeleteTestMainFunc(node)
 			ctxs = append(ctxs, astContexts(node)...)
-
-			destFile := filepath.Join(destDir, testFile)
-			if err = os.MkdirAll(filepath.Dir(destFile), 0755); err != nil {
-				return ctxs, err
-			}
-
-			out, err := os.Create(destFile)
-			if err != nil {
-				return ctxs, err
-			}
-			defer out.Close()
-
-			if err := format.Node(out, fset, node); err != nil {
-				return ctxs, err
-			}
 		}
 	}
+	var failed []string
+	for _, ctx := range ctxs {
+		runes := []rune(ctx)
+		if unicode.IsLower(runes[0]) {
+			expected := append([]rune{unicode.ToUpper(runes[0])}, runes[1:]...)
+			failed = append(failed, fmt.Sprintf("%s - should be: %s", ctx, string(expected)))
+		}
+	}
+	if len(failed) > 0 {
+		return ctxs, fmt.Errorf("godog contexts must be exported:\n\t%s", strings.Join(failed, "\n\t"))
+	}
 	return ctxs, nil
 }
-
-// copyPackageFile simply copies the file, if dest file dir does
-// not exist it creates it
-func copyPackageFile(src, dst string) (err error) {
-	in, err := os.Open(src)
-	if err != nil {
-		return
-	}
-	defer in.Close()
-	if err = os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
-		return
-	}
-	out, err := os.Create(dst)
-	if err != nil {
-		return
-	}
-	defer func() {
-		cerr := out.Close()
-		if err == nil {
-			err = cerr
-		}
-	}()
-	if _, err = io.Copy(out, in); err != nil {
-		return
-	}
-	err = out.Sync()
-	return
-}

cmd/godog/main.go

@@ -5,11 +5,9 @@ import (
 	"io"
 	"os"
 	"os/exec"
-	"path/filepath"
 	"regexp"
 	"strconv"
 	"syscall"
-	"time"
 
 	"github.com/DATA-DOG/godog"
 )
@@ -23,27 +21,10 @@ var stderr = statusOutputFilter(os.Stderr)
 func buildAndRun() (int, error) {
 	var status int
 
-	dir := fmt.Sprintf(filepath.Join("%s", "godog-%d"), os.TempDir(), time.Now().UnixNano())
+	bin, err := godog.Build()
-	err := godog.Build(dir)
 	if err != nil {
 		return 1, err
 	}
-
-	defer os.RemoveAll(dir)
-
-	wd, err := os.Getwd()
-	if err != nil {
-		return 1, err
-	}
-	bin := filepath.Join(wd, "godog.test")
-
-	cmdb := exec.Command("go", "test", "-c", "-o", bin)
-	cmdb.Dir = dir
-	cmdb.Env = os.Environ()
-	if details, err := cmdb.CombinedOutput(); err != nil {
-		fmt.Fprintln(stderr, string(details))
-		return 1, err
-	}
 	defer os.Remove(bin)
 
 	cmd := exec.Command(bin, os.Args[1:]...)

examples/api/api_test.go

@@ -67,7 +67,7 @@ func (a *apiFeature) theResponseShouldMatchJSON(body *gherkin.DocString) (err er
 	return
 }
 
-func featureContext(s *godog.Suite) {
+func FeatureContext(s *godog.Suite) {
 	api := &apiFeature{}
 
 	s.BeforeScenario(api.resetResponse)

examples/api/version.feature

@@ -20,6 +20,6 @@ Feature: get version
     And the response should match json:
       """
       {
-        "version": "v0.4.3"
+        "version": "v0.5.0"
       }
       """

examples/db/api_test.go

@@ -8,7 +8,6 @@ import (
 	"net/http/httptest"
 	"strings"
 
-	"github.com/DATA-DOG/go-txdb"
 	"github.com/DATA-DOG/godog"
 	"github.com/DATA-DOG/godog/gherkin"
 )
@@ -118,7 +117,7 @@ func (a *apiFeature) thereAreUsers(users *gherkin.DataTable) error {
 	return nil
 }
 
-func featureContext(s *godog.Suite) {
+func FeatureContext(s *godog.Suite) {
 	api := &apiFeature{}
 
 	s.BeforeScenario(api.resetResponse)

examples/godogs/godog.go

@@ -1,3 +1,4 @@
+/* file: examples/godogs/godog.go */
 package main
 
 // Godogs to eat

examples/godogs/godog_test.go

@@ -1,3 +1,4 @@
+/* file: examples/godogs/godog_test.go */
 package main
 
 import (
@@ -26,7 +27,7 @@ func thereShouldBeRemaining(remaining int) error {
 	return nil
 }
 
-func featureContext(s *godog.Suite) {
+func FeatureContext(s *godog.Suite) {
 	s.Step(`^there are (\d+) godogs$`, thereAreGodogs)
 	s.Step(`^I eat (\d+)$`, iEat)
 	s.Step(`^there should be (\d+) remaining$`, thereShouldBeRemaining)

features/snippets.feature

@@ -28,7 +28,7 @@ Feature: undefined step snippets
               return godog.ErrPending
       }
 
-      func featureContext(s *godog.Suite) {
+      func FeatureContext(s *godog.Suite) {
               s.Step(`^I send "([^"]*)" request to "([^"]*)"$`, iSendRequestTo)
               s.Step(`^the response code should be (\d+)$`, theResponseCodeShouldBe)
       }
@@ -56,7 +56,7 @@ Feature: undefined step snippets
               return godog.ErrPending
       }
 
-      func featureContext(s *godog.Suite) {
+      func FeatureContext(s *godog.Suite) {
               s.Step(`^I send "([^"]*)" request to "([^"]*)" with:$`, iSendRequestToWith)
               s.Step(`^the response code should be (\d+) and header "([^"]*)" should be "([^"]*)"$`, theResponseCodeShouldBeAndHeaderShouldBe)
       }
@@ -87,7 +87,7 @@ Feature: undefined step snippets
               return godog.ErrPending
       }
 
-      func featureContext(s *godog.Suite) {
+      func FeatureContext(s *godog.Suite) {
               s.Step(`^I pull from github\.com$`, iPullFromGithubcom)
               s.Step(`^the project should be there$`, theProjectShouldBeThere)
       }

fmt.go

@@ -30,7 +30,7 @@ var undefinedSnippetsTpl = template.Must(template.New("snippets").Funcs(snippetH
 	return godog.ErrPending
 }
 
-{{end}}func featureContext(s *godog.Suite) { {{ range . }}
+{{end}}func FeatureContext(s *godog.Suite) { {{ range . }}
 	s.Step({{ backticked .Expr }}, {{ .Method }}){{end}}
 }
 `))

godog.go

@@ -6,13 +6,9 @@ Godog does not intervene with the standard "go test" command and it's behavior.
 You can leverage both frameworks to functionally test your application while
 maintaining all test related source code in *_test.go files.
 
-Godog acts similar compared to go test command. It leverages
+Godog acts similar compared to go test command. It uses go
-a TestMain function introduced in go1.4 and clones the package sources
+compiler and linker tool in order to produce test executable. Godog
-to a temporary build directory. The only change it does is adding a runner
+contexts needs to be exported same as Test functions for go test.
-test.go file and replaces TestMain func if it was used in tests.
-Godog uses standard go ast and build utils to generate test suite package,
-compiles it with go test -c command. It accepts all your environment exported
-build related vars.
 
 For example, imagine you’re about to create the famous UNIX ls command.
 Before you begin, you describe how the feature should work, see the example below..
@@ -46,4 +42,4 @@ Godog was inspired by Behat and Cucumber the above description is taken from it'
 package godog
 
 // Version of package - based on Semantic Versioning 2.0.0 http://semver.org/
-const Version = "v0.4.3"
+const Version = "v0.5.0"

suite_test.go

@@ -2,6 +2,7 @@ package godog
 
 import (
 	"fmt"
+	"path/filepath"
 	"strconv"
 	"strings"
 
@@ -215,8 +216,12 @@ func (s *suiteContext) iShouldHaveNumFeatureFiles(num int, files *gherkin.DocStr
 		return fmt.Errorf("expected %d feature paths to be parsed, but have %d", len(expected), len(actual))
 	}
 	for i := 0; i < len(expected); i++ {
-		if expected[i] != actual[i] {
+		split := strings.Split(expected[i], "/")
-			return fmt.Errorf(`expected feature path "%s" at position: %d, does not match actual "%s"`, expected[i], i, actual[i])
+		exp := filepath.Join(split...)
+		split = strings.Split(actual[i], "/")
+		act := filepath.Join(split...)
+		if exp != act {
+			return fmt.Errorf(`expected feature path "%s" at position: %d, does not match actual "%s"`, exp, i, act)
 		}
 	}
 	return nil

utils.go

@@ -6,6 +6,9 @@ import (
 	"strings"
 )
 
+// empty struct value takes no space allocation
+type void struct{}
+
 // a color code type
 type color int