| 1 | // Copyright 2021 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 typeparams_test |
| 6 | |
| 7 | import ( |
| 8 | "go/ast" |
| 9 | "go/parser" |
| 10 | "go/token" |
| 11 | "go/types" |
| 12 | "regexp" |
| 13 | "strings" |
| 14 | "testing" |
| 15 | |
| 16 | "golang.org/x/tools/internal/typeparams" |
| 17 | . "golang.org/x/tools/internal/typeparams" |
| 18 | ) |
| 19 | |
| 20 | func TestStructuralTerms(t *testing.T) { |
| 21 | if !Enabled { |
| 22 | t.Skip("typeparams are not enabled") |
| 23 | } |
| 24 | |
| 25 | // In the following tests, src must define a type T with (at least) one type |
| 26 | // parameter. We will compute the structural terms of the first type |
| 27 | // parameter. |
| 28 | tests := []struct { |
| 29 | src string |
| 30 | want string |
| 31 | wantError string |
| 32 | }{ |
| 33 | {"package emptyinterface0; type T[P interface{}] int", "all", ""}, |
| 34 | {"package emptyinterface1; type T[P interface{ int | interface{} }] int", "all", ""}, |
| 35 | {"package singleton; type T[P interface{ int }] int", "int", ""}, |
| 36 | {"package under; type T[P interface{~int}] int", "~int", ""}, |
| 37 | {"package superset; type T[P interface{ ~int | int }] int", "~int", ""}, |
| 38 | {"package overlap; type T[P interface{ ~int; int }] int", "int", ""}, |
| 39 | {"package emptyintersection; type T[P interface{ ~int; string }] int", "", "empty type set"}, |
| 40 | |
| 41 | {"package embedded0; type T[P interface{ I }] int; type I interface { int }", "int", ""}, |
| 42 | {"package embedded1; type T[P interface{ I | string }] int; type I interface{ int | ~string }", "int ?\\| ?~string", ""}, |
| 43 | {"package embedded2; type T[P interface{ I; string }] int; type I interface{ int | ~string }", "string", ""}, |
| 44 | |
| 45 | {"package named; type T[P C] int; type C interface{ ~int|int }", "~int", ""}, |
| 46 | {`// package example is taken from the docstring for StructuralTerms |
| 47 | package example |
| 48 | |
| 49 | type A interface{ ~string|~[]byte } |
| 50 | |
| 51 | type B interface{ int|string } |
| 52 | |
| 53 | type C interface { ~string|~int } |
| 54 | |
| 55 | type T[P interface{ A|B; C }] int |
| 56 | `, "~string ?\\| ?int", ""}, |
| 57 | } |
| 58 | |
| 59 | for _, test := range tests { |
| 60 | fset := token.NewFileSet() |
| 61 | f, err := parser.ParseFile(fset, "p.go", test.src, 0) |
| 62 | if err != nil { |
| 63 | t.Fatal(err) |
| 64 | } |
| 65 | t.Run(f.Name.Name, func(t *testing.T) { |
| 66 | conf := types.Config{ |
| 67 | Error: func(error) {}, // keep going on errors |
| 68 | } |
| 69 | pkg, err := conf.Check("", fset, []*ast.File{f}, nil) |
| 70 | if err != nil { |
| 71 | t.Logf("types.Config.Check: %v", err) |
| 72 | // keep going on type checker errors: we want to assert on behavior of |
| 73 | // invalid code as well. |
| 74 | } |
| 75 | obj := pkg.Scope().Lookup("T") |
| 76 | if obj == nil { |
| 77 | t.Fatal("type T not found") |
| 78 | } |
| 79 | T := typeparams.ForNamed(obj.Type().(*types.Named)).At(0) |
| 80 | terms, err := StructuralTerms(T) |
| 81 | if test.wantError != "" { |
| 82 | if err == nil { |
| 83 | t.Fatalf("StructuralTerms(%s): nil error, want %q", T, test.wantError) |
| 84 | } |
| 85 | if !strings.Contains(err.Error(), test.wantError) { |
| 86 | t.Errorf("StructuralTerms(%s): err = %q, want %q", T, err, test.wantError) |
| 87 | } |
| 88 | return |
| 89 | } |
| 90 | if err != nil { |
| 91 | t.Fatal(err) |
| 92 | } |
| 93 | var got string |
| 94 | if len(terms) == 0 { |
| 95 | got = "all" |
| 96 | } else { |
| 97 | qf := types.RelativeTo(pkg) |
| 98 | got = types.TypeString(NewUnion(terms), qf) |
| 99 | } |
| 100 | want := regexp.MustCompile(test.want) |
| 101 | if !want.MatchString(got) { |
| 102 | t.Errorf("StructuralTerms(%s) = %q, want %q", T, got, test.want) |
| 103 | } |
| 104 | }) |
| 105 | } |
| 106 | } |
| 107 |
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