--- /dev/null
+// Copyright 2018 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 facts_test
+
+import (
+ "encoding/gob"
+ "fmt"
+ "go/token"
+ "go/types"
+ "os"
+ "reflect"
+ "testing"
+
+ "golang.org/x/tools/go/analysis/analysistest"
+ "golang.org/x/tools/go/analysis/internal/facts"
+ "golang.org/x/tools/go/packages"
+ "golang.org/x/tools/internal/testenv"
+)
+
+type myFact struct {
+ S string
+}
+
+func (f *myFact) String() string { return fmt.Sprintf("myFact(%s)", f.S) }
+func (f *myFact) AFact() {}
+
+func TestEncodeDecode(t *testing.T) {
+ gob.Register(new(myFact))
+
+ // c -> b -> a, a2
+ // c does not directly depend on a, but it indirectly uses a.T.
+ //
+ // Package a2 is never loaded directly so it is incomplete.
+ //
+ // We use only types in this example because we rely on
+ // types.Eval to resolve the lookup expressions, and it only
+ // works for types. This is a definite gap in the typechecker API.
+ files := map[string]string{
+ "a/a.go": `package a; type A int; type T int`,
+ "a2/a.go": `package a2; type A2 int; type Unneeded int`,
+ "b/b.go": `package b; import ("a"; "a2"); type B chan a2.A2; type F func() a.T`,
+ "c/c.go": `package c; import "b"; type C []b.B`,
+ }
+ dir, cleanup, err := analysistest.WriteFiles(files)
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer cleanup()
+
+ // factmap represents the passing of encoded facts from one
+ // package to another. In practice one would use the file system.
+ factmap := make(map[string][]byte)
+ read := func(path string) ([]byte, error) { return factmap[path], nil }
+
+ // In the following table, we analyze packages (a, b, c) in order,
+ // look up various objects accessible within each package,
+ // and see if they have a fact. The "analysis" exports a fact
+ // for every object at package level.
+ //
+ // Note: Loop iterations are not independent test cases;
+ // order matters, as we populate factmap.
+ type lookups []struct {
+ objexpr string
+ want string
+ }
+ for _, test := range []struct {
+ path string
+ lookups lookups
+ }{
+ {"a", lookups{
+ {"A", "myFact(a.A)"},
+ }},
+ {"b", lookups{
+ {"a.A", "myFact(a.A)"},
+ {"a.T", "myFact(a.T)"},
+ {"B", "myFact(b.B)"},
+ {"F", "myFact(b.F)"},
+ {"F(nil)()", "myFact(a.T)"}, // (result type of b.F)
+ }},
+ {"c", lookups{
+ {"b.B", "myFact(b.B)"},
+ {"b.F", "myFact(b.F)"},
+ //{"b.F(nil)()", "myFact(a.T)"}, // no fact; TODO(adonovan): investigate
+ {"C", "myFact(c.C)"},
+ {"C{}[0]", "myFact(b.B)"},
+ {"<-(C{}[0])", "no fact"}, // object but no fact (we never "analyze" a2)
+ }},
+ } {
+ // load package
+ pkg, err := load(t, dir, test.path)
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ // decode
+ facts, err := facts.Decode(pkg, read)
+ if err != nil {
+ t.Fatalf("Decode failed: %v", err)
+ }
+ if true {
+ t.Logf("decode %s facts = %v", pkg.Path(), facts) // show all facts
+ }
+
+ // export
+ // (one fact for each package-level object)
+ scope := pkg.Scope()
+ for _, name := range scope.Names() {
+ obj := scope.Lookup(name)
+ fact := &myFact{obj.Pkg().Name() + "." + obj.Name()}
+ facts.ExportObjectFact(obj, fact)
+ }
+
+ // import
+ // (after export, because an analyzer may import its own facts)
+ for _, lookup := range test.lookups {
+ fact := new(myFact)
+ var got string
+ if obj := find(pkg, lookup.objexpr); obj == nil {
+ got = "no object"
+ } else if facts.ImportObjectFact(obj, fact) {
+ got = fact.String()
+ } else {
+ got = "no fact"
+ }
+ if got != lookup.want {
+ t.Errorf("in %s, ImportObjectFact(%s, %T) = %s, want %s",
+ pkg.Path(), lookup.objexpr, fact, got, lookup.want)
+ }
+ }
+
+ // encode
+ factmap[pkg.Path()] = facts.Encode()
+ }
+}
+
+func find(p *types.Package, expr string) types.Object {
+ // types.Eval only allows us to compute a TypeName object for an expression.
+ // TODO(adonovan): support other expressions that denote an object:
+ // - an identifier (or qualified ident) for a func, const, or var
+ // - new(T).f for a field or method
+ // I've added CheckExpr in https://go-review.googlesource.com/c/go/+/144677.
+ // If that becomes available, use it.
+
+ // Choose an arbitrary position within the (single-file) package
+ // so that we are within the scope of its import declarations.
+ somepos := p.Scope().Lookup(p.Scope().Names()[0]).Pos()
+ tv, err := types.Eval(token.NewFileSet(), p, somepos, expr)
+ if err != nil {
+ return nil
+ }
+ if n, ok := tv.Type.(*types.Named); ok {
+ return n.Obj()
+ }
+ return nil
+}
+
+func load(t *testing.T, dir string, path string) (*types.Package, error) {
+ cfg := &packages.Config{
+ Mode: packages.LoadSyntax,
+ Dir: dir,
+ Env: append(os.Environ(), "GOPATH="+dir, "GO111MODULE=off", "GOPROXY=off"),
+ }
+ testenv.NeedsGoPackagesEnv(t, cfg.Env)
+ pkgs, err := packages.Load(cfg, path)
+ if err != nil {
+ return nil, err
+ }
+ if packages.PrintErrors(pkgs) > 0 {
+ return nil, fmt.Errorf("packages had errors")
+ }
+ if len(pkgs) == 0 {
+ return nil, fmt.Errorf("no package matched %s", path)
+ }
+ return pkgs[0].Types, nil
+}
+
+type otherFact struct {
+ S string
+}
+
+func (f *otherFact) String() string { return fmt.Sprintf("otherFact(%s)", f.S) }
+func (f *otherFact) AFact() {}
+
+func TestFactFilter(t *testing.T) {
+ files := map[string]string{
+ "a/a.go": `package a; type A int`,
+ }
+ dir, cleanup, err := analysistest.WriteFiles(files)
+ if err != nil {
+ t.Fatal(err)
+ }
+ defer cleanup()
+
+ pkg, err := load(t, dir, "a")
+ if err != nil {
+ t.Fatal(err)
+ }
+
+ obj := pkg.Scope().Lookup("A")
+ s, err := facts.Decode(pkg, func(string) ([]byte, error) { return nil, nil })
+ if err != nil {
+ t.Fatal(err)
+ }
+ s.ExportObjectFact(obj, &myFact{"good object fact"})
+ s.ExportPackageFact(&myFact{"good package fact"})
+ s.ExportObjectFact(obj, &otherFact{"bad object fact"})
+ s.ExportPackageFact(&otherFact{"bad package fact"})
+
+ filter := map[reflect.Type]bool{
+ reflect.TypeOf(&myFact{}): true,
+ }
+
+ pkgFacts := s.AllPackageFacts(filter)
+ wantPkgFacts := `[{package a ("a") myFact(good package fact)}]`
+ if got := fmt.Sprintf("%v", pkgFacts); got != wantPkgFacts {
+ t.Errorf("AllPackageFacts: got %v, want %v", got, wantPkgFacts)
+ }
+
+ objFacts := s.AllObjectFacts(filter)
+ wantObjFacts := "[{type a.A int myFact(good object fact)}]"
+ if got := fmt.Sprintf("%v", objFacts); got != wantObjFacts {
+ t.Errorf("AllObjectFacts: got %v, want %v", got, wantObjFacts)
+ }
+}
projects / dotfiles / .git / blobdiff