go/ssa/testmain.go - tools - Git at Google

 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 package ssa

 // CreateTestMainPackage synthesizes a main package that runs all the
 // tests of the supplied packages.
 // It is closely coupled to $GOROOT/src/cmd/go/test.go and $GOROOT/src/testing.
 //
 // TODO(adonovan): throws this all away now that x/tools/go/packages
 // provides access to the actual synthetic test main files.

 import (
 	"bytes"
 	"fmt"
 	"go/ast"
 	"go/parser"
 	"go/types"
 	"log"
 	"os"
 	"strings"
 	"text/template"
 )

 // FindTests returns the Test, Benchmark, and Example functions
 // (as defined by "go test") defined in the specified package,
 // and its TestMain function, if any.
 //
 // Deprecated: Use golang.org/x/tools/go/packages to access synthetic
 // testmain packages.
 func FindTests(pkg *Package) (tests, benchmarks, examples []*Function, main *Function) {
 	prog := pkg.Prog

 	// The first two of these may be nil: if the program doesn't import "testing",
 	// it can't contain any tests, but it may yet contain Examples.
 	var testSig *types.Signature                              // func(*testing.T)
 	var benchmarkSig *types.Signature                         // func(*testing.B)
 	var exampleSig = types.NewSignature(nil, nil, nil, false) // func()

 	// Obtain the types from the parameters of testing.MainStart.
 	if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil {
 		mainStart := testingPkg.Func("MainStart")
 		params := mainStart.Signature.Params()
 		testSig = funcField(params.At(1).Type())
 		benchmarkSig = funcField(params.At(2).Type())

 		// Does the package define this function?
 		//   func TestMain(*testing.M)
 		if f := pkg.Func("TestMain"); f != nil {
 			sig := f.Type().(*types.Signature)
 			starM := mainStart.Signature.Results().At(0).Type() // *testing.M
 			if sig.Results().Len() == 0 &&
 				sig.Params().Len() == 1 &&
 				types.Identical(sig.Params().At(0).Type(), starM) {
 				main = f
 			}
 		}
 	}

 	// TODO(adonovan): use a stable order, e.g. lexical.
 	for _, mem := range pkg.Members {
 		if f, ok := mem.(*Function); ok &&
 			ast.IsExported(f.Name()) &&
 			strings.HasSuffix(prog.Fset.Position(f.Pos()).Filename, "_test.go") {

 			switch {
 			case testSig != nil && isTestSig(f, "Test", testSig):
 				tests = append(tests, f)
 			case benchmarkSig != nil && isTestSig(f, "Benchmark", benchmarkSig):
 				benchmarks = append(benchmarks, f)
 			case isTestSig(f, "Example", exampleSig):
 				examples = append(examples, f)
 			default:
 				continue
 			}
 		}
 	}
 	return
 }

 // Like isTest, but checks the signature too.
 func isTestSig(f *Function, prefix string, sig *types.Signature) bool {
 	return isTest(f.Name(), prefix) && types.Identical(f.Signature, sig)
 }

 // Given the type of one of the three slice parameters of testing.Main,
 // returns the function type.
 func funcField(slice types.Type) *types.Signature {
 	return slice.(*types.Slice).Elem().Underlying().(*types.Struct).Field(1).Type().(*types.Signature)
 }

 // isTest tells whether name looks like a test (or benchmark, according to prefix).
 // It is a Test (say) if there is a character after Test that is not a lower-case letter.
 // We don't want TesticularCancer.
 // Plundered from $GOROOT/src/cmd/go/test.go
 func isTest(name, prefix string) bool {
 	if !strings.HasPrefix(name, prefix) {
 		return false
 	}
 	if len(name) == len(prefix) { // "Test" is ok
 		return true
 	}
 	return ast.IsExported(name[len(prefix):])
 }

 // CreateTestMainPackage creates and returns a synthetic "testmain"
 // package for the specified package if it defines tests, benchmarks or
 // executable examples, or nil otherwise.  The new package is named
 // "main" and provides a function named "main" that runs the tests,
 // similar to the one that would be created by the 'go test' tool.
 //
 // Subsequent calls to prog.AllPackages include the new package.
 // The package pkg must belong to the program prog.
 //
 // Deprecated: Use golang.org/x/tools/go/packages to access synthetic
 // testmain packages.
 func (prog *Program) CreateTestMainPackage(pkg *Package) *Package {
 	if pkg.Prog != prog {
 		log.Fatal("Package does not belong to Program")
 	}

 	// Template data
 	var data struct {
 		Pkg                         *Package
 		Tests, Benchmarks, Examples []*Function
 		Main                        *Function
 		Go18                        bool
 	}
 	data.Pkg = pkg

 	// Enumerate tests.
 	data.Tests, data.Benchmarks, data.Examples, data.Main = FindTests(pkg)
 	if data.Main == nil &&
 		data.Tests == nil && data.Benchmarks == nil && data.Examples == nil {
 		return nil
 	}

 	// Synthesize source for testmain package.
 	path := pkg.Pkg.Path() + "$testmain"
 	tmpl := testmainTmpl
 	if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil {
 		// In Go 1.8, testing.MainStart's first argument is an interface, not a func.
 		data.Go18 = types.IsInterface(testingPkg.Func("MainStart").Signature.Params().At(0).Type())
 	} else {
 		// The program does not import "testing", but FindTests
 		// returned non-nil, which must mean there were Examples
 		// but no Test, Benchmark, or TestMain functions.

 		// We'll simply call them from testmain.main; this will
 		// ensure they don't panic, but will not check any
 		// "Output:" comments.
 		// (We should not execute an Example that has no
 		// "Output:" comment, but it's impossible to tell here.)
 		tmpl = examplesOnlyTmpl
 	}
 	var buf bytes.Buffer
 	if err := tmpl.Execute(&buf, data); err != nil {
 		log.Fatalf("internal error expanding template for %s: %v", path, err)
 	}
 	if false { // debugging
 		fmt.Fprintln(os.Stderr, buf.String())
 	}

 	// Parse and type-check the testmain package.
 	f, err := parser.ParseFile(prog.Fset, path+".go", &buf, parser.Mode(0))
 	if err != nil {
 		log.Fatalf("internal error parsing %s: %v", path, err)
 	}
 	conf := types.Config{
 		DisableUnusedImportCheck: true,
 		Importer:                 importer{pkg},
 	}
 	files := []*ast.File{f}
 	info := &types.Info{
 		Types:      make(map[ast.Expr]types.TypeAndValue),
 		Defs:       make(map[*ast.Ident]types.Object),
 		Uses:       make(map[*ast.Ident]types.Object),
 		Implicits:  make(map[ast.Node]types.Object),
 		Scopes:     make(map[ast.Node]*types.Scope),
 		Selections: make(map[*ast.SelectorExpr]*types.Selection),
 	}
 	testmainPkg, err := conf.Check(path, prog.Fset, files, info)
 	if err != nil {
 		log.Fatalf("internal error type-checking %s: %v", path, err)
 	}

 	// Create and build SSA code.
 	testmain := prog.CreatePackage(testmainPkg, files, info, false)
 	testmain.SetDebugMode(false)
 	testmain.Build()
 	testmain.Func("main").Synthetic = "test main function"
 	testmain.Func("init").Synthetic = "package initializer"
 	return testmain
 }

 // An implementation of types.Importer for an already loaded SSA program.
 type importer struct {
 	pkg *Package // package under test; may be non-importable
 }

 func (imp importer) Import(path string) (*types.Package, error) {
 	if p := imp.pkg.Prog.ImportedPackage(path); p != nil {
 		return p.Pkg, nil
 	}
 	if path == imp.pkg.Pkg.Path() {
 		return imp.pkg.Pkg, nil
 	}
 	return nil, fmt.Errorf("not found") // can't happen
 }

 var testmainTmpl = template.Must(template.New("testmain").Parse(`
 package main

 import "io"
 import "os"
 import "testing"
 import p {{printf "%q" .Pkg.Pkg.Path}}

 {{if .Go18}}
 type deps struct{}

 func (deps) ImportPath() string { return "" }
 func (deps) MatchString(pat, str string) (bool, error) { return true, nil }
 func (deps) StartCPUProfile(io.Writer) error { return nil }
 func (deps) StartTestLog(io.Writer) {}
 func (deps) StopCPUProfile() {}
 func (deps) StopTestLog() error { return nil }
 func (deps) WriteHeapProfile(io.Writer) error { return nil }
 func (deps) WriteProfileTo(string, io.Writer, int) error { return nil }

 var match deps
 {{else}}
 func match(_, _ string) (bool, error) { return true, nil }
 {{end}}

 func main() {
 	tests := []testing.InternalTest{
 {{range .Tests}}
 		{ {{printf "%q" .Name}}, p.{{.Name}} },
 {{end}}
 	}
 	benchmarks := []testing.InternalBenchmark{
 {{range .Benchmarks}}
 		{ {{printf "%q" .Name}}, p.{{.Name}} },
 {{end}}
 	}
 	examples := []testing.InternalExample{
 {{range .Examples}}
 		{Name: {{printf "%q" .Name}}, F: p.{{.Name}}},
 {{end}}
 	}
 	m := testing.MainStart(match, tests, benchmarks, examples)
 {{with .Main}}
 	p.{{.Name}}(m)
 {{else}}
 	os.Exit(m.Run())
 {{end}}
 }

 `))

 var examplesOnlyTmpl = template.Must(template.New("examples").Parse(`
 package main

 import p {{printf "%q" .Pkg.Pkg.Path}}

 func main() {
 {{range .Examples}}
 	p.{{.Name}}()
 {{end}}
 }
 `))
	// Copyright 2013 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	package ssa

	// CreateTestMainPackage synthesizes a main package that runs all the
	// tests of the supplied packages.
	// It is closely coupled to $GOROOT/src/cmd/go/test.go and $GOROOT/src/testing.
	//
	// TODO(adonovan): throws this all away now that x/tools/go/packages
	// provides access to the actual synthetic test main files.

	import (
	"bytes"
	"fmt"
	"go/ast"
	"go/parser"
	"go/types"
	"log"
	"os"
	"strings"
	"text/template"
	)

	// FindTests returns the Test, Benchmark, and Example functions
	// (as defined by "go test") defined in the specified package,
	// and its TestMain function, if any.
	//
	// Deprecated: Use golang.org/x/tools/go/packages to access synthetic
	// testmain packages.
	func FindTests(pkg Package) (tests, benchmarks, examples []Function, main *Function) {
	prog := pkg.Prog

	// The first two of these may be nil: if the program doesn't import "testing",
	// it can't contain any tests, but it may yet contain Examples.
	var testSig types.Signature // func(testing.T)
	var benchmarkSig types.Signature // func(testing.B)
	var exampleSig = types.NewSignature(nil, nil, nil, false) // func()

	// Obtain the types from the parameters of testing.MainStart.
	if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil {
	mainStart := testingPkg.Func("MainStart")
	params := mainStart.Signature.Params()
	testSig = funcField(params.At(1).Type())
	benchmarkSig = funcField(params.At(2).Type())

	// Does the package define this function?
	// func TestMain(*testing.M)
	if f := pkg.Func("TestMain"); f != nil {
	sig := f.Type().(*types.Signature)
	starM := mainStart.Signature.Results().At(0).Type() // *testing.M
	if sig.Results().Len() == 0 &&
	sig.Params().Len() == 1 &&
	types.Identical(sig.Params().At(0).Type(), starM) {
	main = f
	}
	}
	}

	// TODO(adonovan): use a stable order, e.g. lexical.
	for _, mem := range pkg.Members {
	if f, ok := mem.(*Function); ok &&
	ast.IsExported(f.Name()) &&
	strings.HasSuffix(prog.Fset.Position(f.Pos()).Filename, "_test.go") {

	switch {
	case testSig != nil && isTestSig(f, "Test", testSig):
	tests = append(tests, f)
	case benchmarkSig != nil && isTestSig(f, "Benchmark", benchmarkSig):
	benchmarks = append(benchmarks, f)
	case isTestSig(f, "Example", exampleSig):
	examples = append(examples, f)
	default:
	continue
	}
	}
	}
	return
	}

	// Like isTest, but checks the signature too.
	func isTestSig(f Function, prefix string, sig types.Signature) bool {
	return isTest(f.Name(), prefix) && types.Identical(f.Signature, sig)
	}

	// Given the type of one of the three slice parameters of testing.Main,
	// returns the function type.
	func funcField(slice types.Type) *types.Signature {
	return slice.(types.Slice).Elem().Underlying().(types.Struct).Field(1).Type().(*types.Signature)
	}

	// isTest tells whether name looks like a test (or benchmark, according to prefix).
	// It is a Test (say) if there is a character after Test that is not a lower-case letter.
	// We don't want TesticularCancer.
	// Plundered from $GOROOT/src/cmd/go/test.go
	func isTest(name, prefix string) bool {
	if !strings.HasPrefix(name, prefix) {
	return false
	}
	if len(name) == len(prefix) { // "Test" is ok
	return true
	}
	return ast.IsExported(name[len(prefix):])
	}

	// CreateTestMainPackage creates and returns a synthetic "testmain"
	// package for the specified package if it defines tests, benchmarks or
	// executable examples, or nil otherwise. The new package is named
	// "main" and provides a function named "main" that runs the tests,
	// similar to the one that would be created by the 'go test' tool.
	//
	// Subsequent calls to prog.AllPackages include the new package.
	// The package pkg must belong to the program prog.
	//
	// Deprecated: Use golang.org/x/tools/go/packages to access synthetic
	// testmain packages.
	func (prog Program) CreateTestMainPackage(pkg Package) *Package {
	if pkg.Prog != prog {
	log.Fatal("Package does not belong to Program")
	}

	// Template data
	var data struct {
	Pkg *Package
	Tests, Benchmarks, Examples []*Function
	Main *Function
	Go18 bool
	}
	data.Pkg = pkg

	// Enumerate tests.
	data.Tests, data.Benchmarks, data.Examples, data.Main = FindTests(pkg)
	if data.Main == nil &&
	data.Tests == nil && data.Benchmarks == nil && data.Examples == nil {
	return nil
	}

	// Synthesize source for testmain package.
	path := pkg.Pkg.Path() + "$testmain"
	tmpl := testmainTmpl
	if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil {
	// In Go 1.8, testing.MainStart's first argument is an interface, not a func.
	data.Go18 = types.IsInterface(testingPkg.Func("MainStart").Signature.Params().At(0).Type())
	} else {
	// The program does not import "testing", but FindTests
	// returned non-nil, which must mean there were Examples
	// but no Test, Benchmark, or TestMain functions.

	// We'll simply call them from testmain.main; this will
	// ensure they don't panic, but will not check any
	// "Output:" comments.
	// (We should not execute an Example that has no
	// "Output:" comment, but it's impossible to tell here.)
	tmpl = examplesOnlyTmpl
	}
	var buf bytes.Buffer
	if err := tmpl.Execute(&buf, data); err != nil {
	log.Fatalf("internal error expanding template for %s: %v", path, err)
	}
	if false { // debugging
	fmt.Fprintln(os.Stderr, buf.String())
	}

	// Parse and type-check the testmain package.
	f, err := parser.ParseFile(prog.Fset, path+".go", &buf, parser.Mode(0))
	if err != nil {
	log.Fatalf("internal error parsing %s: %v", path, err)
	}
	conf := types.Config{
	DisableUnusedImportCheck: true,
	Importer: importer{pkg},
	}
	files := []*ast.File{f}
	info := &types.Info{
	Types: make(map[ast.Expr]types.TypeAndValue),
	Defs: make(map[*ast.Ident]types.Object),
	Uses: make(map[*ast.Ident]types.Object),
	Implicits: make(map[ast.Node]types.Object),
	Scopes: make(map[ast.Node]*types.Scope),
	Selections: make(map[ast.SelectorExpr]types.Selection),
	}
	testmainPkg, err := conf.Check(path, prog.Fset, files, info)
	if err != nil {
	log.Fatalf("internal error type-checking %s: %v", path, err)
	}

	// Create and build SSA code.
	testmain := prog.CreatePackage(testmainPkg, files, info, false)
	testmain.SetDebugMode(false)
	testmain.Build()
	testmain.Func("main").Synthetic = "test main function"
	testmain.Func("init").Synthetic = "package initializer"
	return testmain
	}

	// An implementation of types.Importer for an already loaded SSA program.
	type importer struct {
	pkg *Package // package under test; may be non-importable
	}

	func (imp importer) Import(path string) (*types.Package, error) {
	if p := imp.pkg.Prog.ImportedPackage(path); p != nil {
	return p.Pkg, nil
	}
	if path == imp.pkg.Pkg.Path() {
	return imp.pkg.Pkg, nil
	}
	return nil, fmt.Errorf("not found") // can't happen
	}

	var testmainTmpl = template.Must(template.New("testmain").Parse(`
	package main

	import "io"
	import "os"
	import "testing"
	import p {{printf "%q" .Pkg.Pkg.Path}}

	{{if .Go18}}
	type deps struct{}

	func (deps) ImportPath() string { return "" }
	func (deps) MatchString(pat, str string) (bool, error) { return true, nil }
	func (deps) StartCPUProfile(io.Writer) error { return nil }
	func (deps) StartTestLog(io.Writer) {}
	func (deps) StopCPUProfile() {}
	func (deps) StopTestLog() error { return nil }
	func (deps) WriteHeapProfile(io.Writer) error { return nil }
	func (deps) WriteProfileTo(string, io.Writer, int) error { return nil }

	var match deps
	{{else}}
	func match(_, _ string) (bool, error) { return true, nil }
	{{end}}

	func main() {
	tests := []testing.InternalTest{
	{{range .Tests}}
	{ {{printf "%q" .Name}}, p.{{.Name}} },
	{{end}}
	}
	benchmarks := []testing.InternalBenchmark{
	{{range .Benchmarks}}
	{ {{printf "%q" .Name}}, p.{{.Name}} },
	{{end}}
	}
	examples := []testing.InternalExample{
	{{range .Examples}}
	{Name: {{printf "%q" .Name}}, F: p.{{.Name}}},
	{{end}}
	}
	m := testing.MainStart(match, tests, benchmarks, examples)
	{{with .Main}}
	p.{{.Name}}(m)
	{{else}}
	os.Exit(m.Run())
	{{end}}
	}

	`))

	var examplesOnlyTmpl = template.Must(template.New("examples").Parse(`
	package main

	import p {{printf "%q" .Pkg.Pkg.Path}}

	func main() {
	{{range .Examples}}
	p.{{.Name}}()
	{{end}}
	}
	`))