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// 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): this file no longer needs to live in the ssa package.
// Move it to ssautil.
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.
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 $GOROOT/src/cmd/go/test.go
func isTest(name, prefix string) bool {
if !strings.HasPrefix(name, prefix) {
return false
}
if len(name) == len(prefix) { // "Test" is ok
return true
}
return ast.IsExported(name[len(prefix):])
}
// CreateTestMainPackage creates and returns a synthetic "testmain"
// package for the specified package if it defines tests, benchmarks or
// executable examples, or nil otherwise. The new package is named
// "main" and provides a function named "main" that runs the tests,
// similar to the one that would be created by the 'go test' tool.
//
// Subsequent calls to prog.AllPackages include the new package.
// The package pkg must belong to the program prog.
func (prog *Program) CreateTestMainPackage(pkg *Package) *Package {
if pkg.Prog != prog {
log.Fatal("Package does not belong to Program")
}
// Template data
var data struct {
Pkg *Package
Tests, Benchmarks, Examples []*Function
Main *Function
Go18 bool
}
data.Pkg = pkg
// Enumerate tests.
data.Tests, data.Benchmarks, data.Examples, data.Main = FindTests(pkg)
if data.Main == nil &&
data.Tests == nil && data.Benchmarks == nil && data.Examples == nil {
return nil
}
// Synthesize source for testmain package.
path := pkg.Pkg.Path() + "$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}}
}
`))