| 1 | // Copyright 2018 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package facts_test |
| 6 | |
| 7 | import ( |
| 8 | "encoding/gob" |
| 9 | "fmt" |
| 10 | "go/token" |
| 11 | "go/types" |
| 12 | "os" |
| 13 | "reflect" |
| 14 | "testing" |
| 15 | |
| 16 | "golang.org/x/tools/go/analysis/analysistest" |
| 17 | "golang.org/x/tools/go/packages" |
| 18 | "golang.org/x/tools/internal/facts" |
| 19 | "golang.org/x/tools/internal/testenv" |
| 20 | "golang.org/x/tools/internal/typeparams" |
| 21 | ) |
| 22 | |
| 23 | type myFact struct { |
| 24 | S string |
| 25 | } |
| 26 | |
| 27 | func (f *myFact) String() string { return fmt.Sprintf("myFact(%s)", f.S) } |
| 28 | func (f *myFact) AFact() {} |
| 29 | |
| 30 | func init() { |
| 31 | gob.Register(new(myFact)) |
| 32 | } |
| 33 | |
| 34 | func TestEncodeDecode(t *testing.T) { |
| 35 | tests := []struct { |
| 36 | name string |
| 37 | typeparams bool // requires typeparams to be enabled |
| 38 | files map[string]string |
| 39 | plookups []pkgLookups // see testEncodeDecode for details |
| 40 | }{ |
| 41 | { |
| 42 | name: "loading-order", |
| 43 | // c -> b -> a, a2 |
| 44 | // c does not directly depend on a, but it indirectly uses a.T. |
| 45 | // |
| 46 | // Package a2 is never loaded directly so it is incomplete. |
| 47 | // |
| 48 | // We use only types in this example because we rely on |
| 49 | // types.Eval to resolve the lookup expressions, and it only |
| 50 | // works for types. This is a definite gap in the typechecker API. |
| 51 | files: map[string]string{ |
| 52 | "a/a.go": `package a; type A int; type T int`, |
| 53 | "a2/a.go": `package a2; type A2 int; type Unneeded int`, |
| 54 | "b/b.go": `package b; import ("a"; "a2"); type B chan a2.A2; type F func() a.T`, |
| 55 | "c/c.go": `package c; import "b"; type C []b.B`, |
| 56 | }, |
| 57 | // In the following table, we analyze packages (a, b, c) in order, |
| 58 | // look up various objects accessible within each package, |
| 59 | // and see if they have a fact. The "analysis" exports a fact |
| 60 | // for every object at package level. |
| 61 | // |
| 62 | // Note: Loop iterations are not independent test cases; |
| 63 | // order matters, as we populate factmap. |
| 64 | plookups: []pkgLookups{ |
| 65 | {"a", []lookup{ |
| 66 | {"A", "myFact(a.A)"}, |
| 67 | }}, |
| 68 | {"b", []lookup{ |
| 69 | {"a.A", "myFact(a.A)"}, |
| 70 | {"a.T", "myFact(a.T)"}, |
| 71 | {"B", "myFact(b.B)"}, |
| 72 | {"F", "myFact(b.F)"}, |
| 73 | {"F(nil)()", "myFact(a.T)"}, // (result type of b.F) |
| 74 | }}, |
| 75 | {"c", []lookup{ |
| 76 | {"b.B", "myFact(b.B)"}, |
| 77 | {"b.F", "myFact(b.F)"}, |
| 78 | //{"b.F(nil)()", "myFact(a.T)"}, // no fact; TODO(adonovan): investigate |
| 79 | {"C", "myFact(c.C)"}, |
| 80 | {"C{}[0]", "myFact(b.B)"}, |
| 81 | {"<-(C{}[0])", "no fact"}, // object but no fact (we never "analyze" a2) |
| 82 | }}, |
| 83 | }, |
| 84 | }, |
| 85 | { |
| 86 | name: "globals", |
| 87 | files: map[string]string{ |
| 88 | "a/a.go": `package a; |
| 89 | type T1 int |
| 90 | type T2 int |
| 91 | type T3 int |
| 92 | type T4 int |
| 93 | type T5 int |
| 94 | type K int; type V string |
| 95 | `, |
| 96 | "b/b.go": `package b |
| 97 | import "a" |
| 98 | var ( |
| 99 | G1 []a.T1 |
| 100 | G2 [7]a.T2 |
| 101 | G3 chan a.T3 |
| 102 | G4 *a.T4 |
| 103 | G5 struct{ F a.T5 } |
| 104 | G6 map[a.K]a.V |
| 105 | ) |
| 106 | `, |
| 107 | "c/c.go": `package c; import "b"; |
| 108 | var ( |
| 109 | v1 = b.G1 |
| 110 | v2 = b.G2 |
| 111 | v3 = b.G3 |
| 112 | v4 = b.G4 |
| 113 | v5 = b.G5 |
| 114 | v6 = b.G6 |
| 115 | ) |
| 116 | `, |
| 117 | }, |
| 118 | plookups: []pkgLookups{ |
| 119 | {"a", []lookup{}}, |
| 120 | {"b", []lookup{}}, |
| 121 | {"c", []lookup{ |
| 122 | {"v1[0]", "myFact(a.T1)"}, |
| 123 | {"v2[0]", "myFact(a.T2)"}, |
| 124 | {"<-v3", "myFact(a.T3)"}, |
| 125 | {"*v4", "myFact(a.T4)"}, |
| 126 | {"v5.F", "myFact(a.T5)"}, |
| 127 | {"v6[0]", "myFact(a.V)"}, |
| 128 | }}, |
| 129 | }, |
| 130 | }, |
| 131 | { |
| 132 | name: "typeparams", |
| 133 | typeparams: true, |
| 134 | files: map[string]string{ |
| 135 | "a/a.go": `package a |
| 136 | type T1 int |
| 137 | type T2 int |
| 138 | type T3 interface{Foo()} |
| 139 | type T4 int |
| 140 | type T5 int |
| 141 | type T6 interface{Foo()} |
| 142 | `, |
| 143 | "b/b.go": `package b |
| 144 | import "a" |
| 145 | type N1[T a.T1|int8] func() T |
| 146 | type N2[T any] struct{ F T } |
| 147 | type N3[T a.T3] func() T |
| 148 | type N4[T a.T4|int8] func() T |
| 149 | type N5[T interface{Bar() a.T5} ] func() T |
| 150 | |
| 151 | type t5 struct{}; func (t5) Bar() a.T5 { return 0 } |
| 152 | |
| 153 | var G1 N1[a.T1] |
| 154 | var G2 func() N2[a.T2] |
| 155 | var G3 N3[a.T3] |
| 156 | var G4 N4[a.T4] |
| 157 | var G5 N5[t5] |
| 158 | |
| 159 | func F6[T a.T6]() T { var x T; return x } |
| 160 | `, |
| 161 | "c/c.go": `package c; import "b"; |
| 162 | var ( |
| 163 | v1 = b.G1 |
| 164 | v2 = b.G2 |
| 165 | v3 = b.G3 |
| 166 | v4 = b.G4 |
| 167 | v5 = b.G5 |
| 168 | v6 = b.F6[t6] |
| 169 | ) |
| 170 | |
| 171 | type t6 struct{}; func (t6) Foo() {} |
| 172 | `, |
| 173 | }, |
| 174 | plookups: []pkgLookups{ |
| 175 | {"a", []lookup{}}, |
| 176 | {"b", []lookup{}}, |
| 177 | {"c", []lookup{ |
| 178 | {"v1", "myFact(b.N1)"}, |
| 179 | {"v1()", "myFact(a.T1)"}, |
| 180 | {"v2()", "myFact(b.N2)"}, |
| 181 | {"v2().F", "myFact(a.T2)"}, |
| 182 | {"v3", "myFact(b.N3)"}, |
| 183 | {"v4", "myFact(b.N4)"}, |
| 184 | {"v4()", "myFact(a.T4)"}, |
| 185 | {"v5", "myFact(b.N5)"}, |
| 186 | {"v5()", "myFact(b.t5)"}, |
| 187 | {"v6()", "myFact(c.t6)"}, |
| 188 | }}, |
| 189 | }, |
| 190 | }, |
| 191 | } |
| 192 | |
| 193 | for i := range tests { |
| 194 | test := tests[i] |
| 195 | t.Run(test.name, func(t *testing.T) { |
| 196 | t.Parallel() |
| 197 | if test.typeparams && !typeparams.Enabled { |
| 198 | t.Skip("type parameters are not enabled") |
| 199 | } |
| 200 | testEncodeDecode(t, test.files, test.plookups) |
| 201 | }) |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | type lookup struct { |
| 206 | objexpr string |
| 207 | want string |
| 208 | } |
| 209 | |
| 210 | type pkgLookups struct { |
| 211 | path string |
| 212 | lookups []lookup |
| 213 | } |
| 214 | |
| 215 | // testEncodeDecode tests fact encoding and decoding and simulates how package facts |
| 216 | // are passed during analysis. It operates on a group of Go file contents. Then |
| 217 | // for each <package, []lookup> in tests it does the following: |
| 218 | // 1. loads and type checks the package, |
| 219 | // 2. calls (*facts.Decoder).Decode to load the facts exported by its imports, |
| 220 | // 3. exports a myFact Fact for all of package level objects, |
| 221 | // 4. For each lookup for the current package: |
| 222 | // 4.a) lookup the types.Object for an Go source expression in the curent package |
| 223 | // (or confirms one is not expected want=="no object"), |
| 224 | // 4.b) finds a Fact for the object (or confirms one is not expected want=="no fact"), |
| 225 | // 4.c) compares the content of the Fact to want. |
| 226 | // 5. encodes the Facts of the package. |
| 227 | // |
| 228 | // Note: tests are not independent test cases; order matters (as does a package being |
| 229 | // skipped). It changes what Facts can be imported. |
| 230 | // |
| 231 | // Failures are reported on t. |
| 232 | func testEncodeDecode(t *testing.T, files map[string]string, tests []pkgLookups) { |
| 233 | dir, cleanup, err := analysistest.WriteFiles(files) |
| 234 | if err != nil { |
| 235 | t.Fatal(err) |
| 236 | } |
| 237 | defer cleanup() |
| 238 | |
| 239 | // factmap represents the passing of encoded facts from one |
| 240 | // package to another. In practice one would use the file system. |
| 241 | factmap := make(map[string][]byte) |
| 242 | read := func(imp *types.Package) ([]byte, error) { return factmap[imp.Path()], nil } |
| 243 | |
| 244 | // Analyze packages in order, look up various objects accessible within |
| 245 | // each package, and see if they have a fact. The "analysis" exports a |
| 246 | // fact for every object at package level. |
| 247 | // |
| 248 | // Note: Loop iterations are not independent test cases; |
| 249 | // order matters, as we populate factmap. |
| 250 | for _, test := range tests { |
| 251 | // load package |
| 252 | pkg, err := load(t, dir, test.path) |
| 253 | if err != nil { |
| 254 | t.Fatal(err) |
| 255 | } |
| 256 | |
| 257 | // decode |
| 258 | facts, err := facts.NewDecoder(pkg).Decode(read) |
| 259 | if err != nil { |
| 260 | t.Fatalf("Decode failed: %v", err) |
| 261 | } |
| 262 | t.Logf("decode %s facts = %v", pkg.Path(), facts) // show all facts |
| 263 | |
| 264 | // export |
| 265 | // (one fact for each package-level object) |
| 266 | for _, name := range pkg.Scope().Names() { |
| 267 | obj := pkg.Scope().Lookup(name) |
| 268 | fact := &myFact{obj.Pkg().Name() + "." + obj.Name()} |
| 269 | facts.ExportObjectFact(obj, fact) |
| 270 | } |
| 271 | t.Logf("exported %s facts = %v", pkg.Path(), facts) // show all facts |
| 272 | |
| 273 | // import |
| 274 | // (after export, because an analyzer may import its own facts) |
| 275 | for _, lookup := range test.lookups { |
| 276 | fact := new(myFact) |
| 277 | var got string |
| 278 | if obj := find(pkg, lookup.objexpr); obj == nil { |
| 279 | got = "no object" |
| 280 | } else if facts.ImportObjectFact(obj, fact) { |
| 281 | got = fact.String() |
| 282 | } else { |
| 283 | got = "no fact" |
| 284 | } |
| 285 | if got != lookup.want { |
| 286 | t.Errorf("in %s, ImportObjectFact(%s, %T) = %s, want %s", |
| 287 | pkg.Path(), lookup.objexpr, fact, got, lookup.want) |
| 288 | } |
| 289 | } |
| 290 | |
| 291 | // encode |
| 292 | factmap[pkg.Path()] = facts.Encode() |
| 293 | } |
| 294 | } |
| 295 | |
| 296 | func find(p *types.Package, expr string) types.Object { |
| 297 | // types.Eval only allows us to compute a TypeName object for an expression. |
| 298 | // TODO(adonovan): support other expressions that denote an object: |
| 299 | // - an identifier (or qualified ident) for a func, const, or var |
| 300 | // - new(T).f for a field or method |
| 301 | // I've added CheckExpr in https://go-review.googlesource.com/c/go/+/144677. |
| 302 | // If that becomes available, use it. |
| 303 | |
| 304 | // Choose an arbitrary position within the (single-file) package |
| 305 | // so that we are within the scope of its import declarations. |
| 306 | somepos := p.Scope().Lookup(p.Scope().Names()[0]).Pos() |
| 307 | tv, err := types.Eval(token.NewFileSet(), p, somepos, expr) |
| 308 | if err != nil { |
| 309 | return nil |
| 310 | } |
| 311 | if n, ok := tv.Type.(*types.Named); ok { |
| 312 | return n.Obj() |
| 313 | } |
| 314 | return nil |
| 315 | } |
| 316 | |
| 317 | func load(t *testing.T, dir string, path string) (*types.Package, error) { |
| 318 | cfg := &packages.Config{ |
| 319 | Mode: packages.LoadSyntax, |
| 320 | Dir: dir, |
| 321 | Env: append(os.Environ(), "GOPATH="+dir, "GO111MODULE=off", "GOPROXY=off"), |
| 322 | } |
| 323 | testenv.NeedsGoPackagesEnv(t, cfg.Env) |
| 324 | pkgs, err := packages.Load(cfg, path) |
| 325 | if err != nil { |
| 326 | return nil, err |
| 327 | } |
| 328 | if packages.PrintErrors(pkgs) > 0 { |
| 329 | return nil, fmt.Errorf("packages had errors") |
| 330 | } |
| 331 | if len(pkgs) == 0 { |
| 332 | return nil, fmt.Errorf("no package matched %s", path) |
| 333 | } |
| 334 | return pkgs[0].Types, nil |
| 335 | } |
| 336 | |
| 337 | type otherFact struct { |
| 338 | S string |
| 339 | } |
| 340 | |
| 341 | func (f *otherFact) String() string { return fmt.Sprintf("otherFact(%s)", f.S) } |
| 342 | func (f *otherFact) AFact() {} |
| 343 | |
| 344 | func TestFactFilter(t *testing.T) { |
| 345 | files := map[string]string{ |
| 346 | "a/a.go": `package a; type A int`, |
| 347 | } |
| 348 | dir, cleanup, err := analysistest.WriteFiles(files) |
| 349 | if err != nil { |
| 350 | t.Fatal(err) |
| 351 | } |
| 352 | defer cleanup() |
| 353 | |
| 354 | pkg, err := load(t, dir, "a") |
| 355 | if err != nil { |
| 356 | t.Fatal(err) |
| 357 | } |
| 358 | |
| 359 | obj := pkg.Scope().Lookup("A") |
| 360 | s, err := facts.NewDecoder(pkg).Decode(func(*types.Package) ([]byte, error) { return nil, nil }) |
| 361 | if err != nil { |
| 362 | t.Fatal(err) |
| 363 | } |
| 364 | s.ExportObjectFact(obj, &myFact{"good object fact"}) |
| 365 | s.ExportPackageFact(&myFact{"good package fact"}) |
| 366 | s.ExportObjectFact(obj, &otherFact{"bad object fact"}) |
| 367 | s.ExportPackageFact(&otherFact{"bad package fact"}) |
| 368 | |
| 369 | filter := map[reflect.Type]bool{ |
| 370 | reflect.TypeOf(&myFact{}): true, |
| 371 | } |
| 372 | |
| 373 | pkgFacts := s.AllPackageFacts(filter) |
| 374 | wantPkgFacts := `[{package a ("a") myFact(good package fact)}]` |
| 375 | if got := fmt.Sprintf("%v", pkgFacts); got != wantPkgFacts { |
| 376 | t.Errorf("AllPackageFacts: got %v, want %v", got, wantPkgFacts) |
| 377 | } |
| 378 | |
| 379 | objFacts := s.AllObjectFacts(filter) |
| 380 | wantObjFacts := "[{type a.A int myFact(good object fact)}]" |
| 381 | if got := fmt.Sprintf("%v", objFacts); got != wantObjFacts { |
| 382 | t.Errorf("AllObjectFacts: got %v, want %v", got, wantObjFacts) |
| 383 | } |
| 384 | } |
| 385 |
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