1 files changed, 80 insertions, 0 deletions
diff --git a/gopls/internal/regtest/workspace/misspelling_test.go b/gopls/internal/regtest/workspace/misspelling_test.go
new file mode 100644
index 000000000..0419a1163
--- /dev/null
+++ b/gopls/internal/regtest/workspace/misspelling_test.go
@@ -0,0 +1,80 @@
+// Copyright 2023 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.
+
+package workspace
+
+import (
+	"runtime"
+	"testing"
+
+	. "golang.org/x/tools/gopls/internal/lsp/regtest"
+	"golang.org/x/tools/gopls/internal/lsp/tests/compare"
+)
+
+// Test for golang/go#57081.
+func TestFormattingMisspelledURI(t *testing.T) {
+	if runtime.GOOS != "windows" && runtime.GOOS != "darwin" {
+		t.Skip("golang/go#57081 only reproduces on case-insensitive filesystems.")
+	}
+	const files = `
+-- go.mod --
+module mod.test
+
+go 1.19
+-- foo.go --
+package foo
+
+const  C = 2 // extra space is intentional
+`
+
+	Run(t, files, func(t *testing.T, env *Env) {
+		env.OpenFile("Foo.go")
+		env.FormatBuffer("Foo.go")
+		want := env.BufferText("Foo.go")
+
+		if want == "" {
+			t.Fatalf("Foo.go is empty")
+		}
+
+		// In golang/go#57081, we observed that if overlay cases don't match, gopls
+		// will find (and format) the on-disk contents rather than the overlay,
+		// resulting in invalid edits.
+		//
+		// Verify that this doesn't happen, by confirming that formatting is
+		// idempotent.
+		env.FormatBuffer("Foo.go")
+		got := env.BufferText("Foo.go")
+		if diff := compare.Text(want, got); diff != "" {
+			t.Errorf("invalid content after second formatting:\n%s", diff)
+		}
+	})
+}
+
+// Test that we can find packages for open files with different spelling on
+// case-insensitive file systems.
+func TestPackageForMisspelledURI(t *testing.T) {
+	t.Skip("golang/go#57081: this test fails because the Go command does not load Foo.go correctly")
+	if runtime.GOOS != "windows" && runtime.GOOS != "darwin" {
+		t.Skip("golang/go#57081 only reproduces on case-insensitive filesystems.")
+	}
+	const files = `
+-- go.mod --
+module mod.test
+
+go 1.19
+-- foo.go --
+package foo
+
+const C = D
+-- bar.go --
+package foo
+
+const D = 2
+`
+
+	Run(t, files, func(t *testing.T, env *Env) {
+		env.OpenFile("Foo.go")
+		env.AfterChange(NoDiagnostics())
+	})
+}