constraints: test against the constraints package from x/exp instead of std
Fixes golang/go#50792
Change-Id: I9abb0972c9e51c88591de1cc1ef10337f75f84d0
Reviewed-on: https://go-review.googlesource.com/c/exp/+/382834
Trust: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
diff --git a/constraints/constraints_test.go b/constraints/constraints_test.go
index a285ee6..5bc43a9 100644
--- a/constraints/constraints_test.go
+++ b/constraints/constraints_test.go
@@ -42,7 +42,7 @@
var prolog = []byte(`
package constrainttest
-import "constraints"
+import "golang.org/x/exp/constraints"
type (
testSigned[T constraints.Signed] struct{ f T }
@@ -71,9 +71,40 @@
tmpdir := t.TempDir()
- if err := os.WriteFile(filepath.Join(tmpdir, "go.mod"), []byte("module constraintest"), 0666); err != nil {
+ cwd, err := os.Getwd()
+ if err != nil {
t.Fatal(err)
}
+ // This package is golang.org/x/exp/constraints, so the root of the x/exp
+ // module is the parent directory of the directory in which this test runs.
+ expModDir := filepath.Dir(cwd)
+
+ modFile := fmt.Sprintf(`module constraintest
+
+go 1.18
+
+replace golang.org/x/exp => %s
+`, expModDir)
+ if err := os.WriteFile(filepath.Join(tmpdir, "go.mod"), []byte(modFile), 0666); err != nil {
+ t.Fatal(err)
+ }
+
+ // Write the prolog as its own file so that 'go mod tidy' has something to inspect.
+ // This will ensure that the go.mod and go.sum files include any dependencies
+ // needed by the constraints package (which should just be some version of
+ // x/exp itself).
+ if err := os.WriteFile(filepath.Join(tmpdir, "prolog.go"), []byte(prolog), 0666); err != nil {
+ t.Fatal(err)
+ }
+
+ tidyCmd := exec.Command(gocmd, "mod", "tidy")
+ tidyCmd.Dir = tmpdir
+ tidyCmd.Env = append(os.Environ(), "PWD="+tmpdir)
+ if out, err := tidyCmd.CombinedOutput(); err != nil {
+ t.Fatalf("%v: %v\n%s", tidyCmd, err, out)
+ } else {
+ t.Logf("%v:\n%s", tidyCmd, out)
+ }
// Test for types that should not satisfy a constraint.
// For each pair of constraint and type, write a Go file
