go/build: make TestDependencies work again

CL 243940 accidentally broke TestDependencies such that it always passed.
Make it work again, and add a test so that it won't break in the same way.

This revealed that the new embed package was missing from TestDepencies,
so add it.

Fixes #43249

Change-Id: I02b3e38dd35ad88880c4344d46de13b7639aa4c6
Reviewed-on: https://go-review.googlesource.com/c/go/+/279073
Trust: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

diff --git a/src/go/build/deps_test.go b/src/go/build/deps_test.go
index 56942c0fd2bc8b8cafb606b8e1c8627f886190cb..aa651af718ebaa578e52ad7d422eae938987e655 100644 (file)
--- a/src/go/build/deps_test.go
+++ b/src/go/build/deps_test.go
@@ -10,6 +10,7 @@ package build
 import (
        "bytes"
        "fmt"
+       "go/token"
        "internal/testenv"
        "io/fs"
        "os"
@@ -162,6 +163,9 @@ var depsRules = `
        < os
        < os/signal;
 
+       io/fs
+       < embed;
+
        unicode, fmt !< os, os/signal;
 
        os/signal, STR
@@ -602,6 +606,7 @@ func findImports(pkg string) ([]string, error) {
        }
        var imports []string
        var haveImport = map[string]bool{}
+       fset := token.NewFileSet()
        for _, file := range files {
                name := file.Name()
                if name == "slice_go14.go" || name == "slice_go18.go" {
@@ -611,8 +616,10 @@ func findImports(pkg string) ([]string, error) {
                if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
                        continue
                }
-               var info fileInfo
-               info.name = filepath.Join(dir, name)
+               info := fileInfo{
+                       name: filepath.Join(dir, name),
+                       fset: fset,
+               }
                f, err := os.Open(info.name)
                if err != nil {
                        return nil, err
@@ -840,3 +847,22 @@ func TestStdlibLowercase(t *testing.T) {
                }
        }
 }
+
+// TestFindImports tests that findImports works.  See #43249.
+func TestFindImports(t *testing.T) {
+       imports, err := findImports("go/build")
+       if err != nil {
+               t.Fatal(err)
+       }
+       t.Logf("go/build imports %q", imports)
+       want := []string{"bytes", "os", "path/filepath", "strings"}
+wantLoop:
+       for _, w := range want {
+               for _, imp := range imports {
+                       if imp == w {
+                               continue wantLoop
+                       }
+               }
+               t.Errorf("expected to find %q in import list", w)
+       }
+}