go/analysis/passes/assign: add typeparams test
This CL adds a test for the assign pass that involves use of generics.
Update golang/go#48704
Change-Id: I355e73130c54bdc2363c686a5b28fe3140a307b5
Reviewed-on: https://go-review.googlesource.com/c/tools/+/354610
Reviewed-by: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Emmanuel Odeke <emmanuel@orijtech.com>
diff --git a/go/analysis/passes/assign/assign_test.go b/go/analysis/passes/assign/assign_test.go
index f793e08..146385f 100644
--- a/go/analysis/passes/assign/assign_test.go
+++ b/go/analysis/passes/assign/assign_test.go
@@ -9,9 +9,14 @@
"golang.org/x/tools/go/analysis/analysistest"
"golang.org/x/tools/go/analysis/passes/assign"
+ "golang.org/x/tools/internal/typeparams"
)
func Test(t *testing.T) {
testdata := analysistest.TestData()
- analysistest.RunWithSuggestedFixes(t, testdata, assign.Analyzer, "a")
+ tests := []string{"a"}
+ if typeparams.Enabled {
+ tests = append(tests, "typeparams")
+ }
+ analysistest.RunWithSuggestedFixes(t, testdata, assign.Analyzer, tests...)
}
diff --git a/go/analysis/passes/assign/testdata/src/typeparams/typeparams.go b/go/analysis/passes/assign/testdata/src/typeparams/typeparams.go
new file mode 100644
index 0000000..345db27
--- /dev/null
+++ b/go/analysis/passes/assign/testdata/src/typeparams/typeparams.go
@@ -0,0 +1,33 @@
+// Copyright 2020 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.
+
+// This file contains tests for the useless-assignment checker.
+
+//go:build go1.18
+
+package testdata
+
+import "math/rand"
+
+type ST[T interface{ ~int }] struct {
+ x T
+ l []T
+}
+
+func (s *ST[T]) SetX(x T, ch chan T) {
+ // Accidental self-assignment; it should be "s.x = x"
+ x = x // want "self-assignment of x to x"
+ // Another mistake
+ s.x = s.x // want "self-assignment of s.x to s.x"
+
+ s.l[0] = s.l[0] // want "self-assignment of s.l.0. to s.l.0."
+
+ // Bail on any potential side effects to avoid false positives
+ s.l[num()] = s.l[num()]
+ rng := rand.New(rand.NewSource(0))
+ s.l[rng.Intn(len(s.l))] = s.l[rng.Intn(len(s.l))]
+ s.l[<-ch] = s.l[<-ch]
+}
+
+func num() int { return 2 }
diff --git a/go/analysis/passes/assign/testdata/src/typeparams/typeparams.go.golden b/go/analysis/passes/assign/testdata/src/typeparams/typeparams.go.golden
new file mode 100644
index 0000000..d9384ed
--- /dev/null
+++ b/go/analysis/passes/assign/testdata/src/typeparams/typeparams.go.golden
@@ -0,0 +1,33 @@
+// Copyright 2020 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.
+
+// This file contains tests for the useless-assignment checker.
+
+//go:build go1.18
+
+package testdata
+
+import "math/rand"
+
+type ST[T interface{ ~int }] struct {
+ x T
+ l []T
+}
+
+func (s *ST[T]) SetX(x T, ch chan T) {
+ // Accidental self-assignment; it should be "s.x = x"
+ // want "self-assignment of x to x"
+ // Another mistake
+ // want "self-assignment of s.x to s.x"
+
+ // want "self-assignment of s.l.0. to s.l.0."
+
+ // Bail on any potential side effects to avoid false positives
+ s.l[num()] = s.l[num()]
+ rng := rand.New(rand.NewSource(0))
+ s.l[rng.Intn(len(s.l))] = s.l[rng.Intn(len(s.l))]
+ s.l[<-ch] = s.l[<-ch]
+}
+
+func num() int { return 2 }
