Files
wazero/fsconfig_test.go
Edoardo Vacchi f36d30b82d Ensure nil is accepted as FS config (#1182)
In previous releases, passing a `nil` value as an FS config
did not cause any error. However, in 1.0.0-rc.1 this leads
to the creation of an invalid `adapter{fs: nil}`, which
eventually leads to a panic (nil):

    (f *FileEntry) Stat(st *platform.Stat_t) =>
        (r *lazyDir) file() =>
            r.fs.OpenFile(".", os.O_RDONLY, 0)

with fs == nil

The backwards-compatible fix is to make Adapt()
return UnimplementedFS, and ensuring `nil` is a valid value
that config is able to handle.

However, we may want to consider returning an error somewhere,
because configuring a nil FS may be unintended.

Signed-off-by: Edoardo Vacchi <evacchi@users.noreply.github.com>
2023-03-03 10:01:31 +08:00

112 lines
2.6 KiB
Go

package wazero
import (
"testing"
"github.com/tetratelabs/wazero/internal/sysfs"
testfs "github.com/tetratelabs/wazero/internal/testing/fs"
"github.com/tetratelabs/wazero/internal/testing/require"
)
// TestFSConfig only tests the cases that change the inputs to sysfs.NewRootFS.
func TestFSConfig(t *testing.T) {
base := NewFSConfig()
testFS := testfs.FS{}
testFS2 := testfs.FS{"/": &testfs.File{}}
tests := []struct {
name string
input FSConfig
expected sysfs.FS
}{
{
name: "empty",
input: base,
expected: sysfs.UnimplementedFS{},
},
{
name: "WithFSMount",
input: base.WithFSMount(testFS, "/"),
expected: sysfs.Adapt(testFS),
},
{
name: "WithFSMount overwrites",
input: base.WithFSMount(testFS, "/").WithFSMount(testFS2, "/"),
expected: sysfs.Adapt(testFS2),
},
{
name: "WithFsMount nil",
input: base.WithFSMount(nil, "/"),
expected: sysfs.UnimplementedFS{},
},
{
name: "WithDirMount overwrites",
input: base.WithFSMount(testFS, "/").WithDirMount(".", "/"),
expected: sysfs.NewDirFS("."),
},
{
name: "Composition",
input: base.WithReadOnlyDirMount(".", "/").WithDirMount("/tmp", "/tmp"),
expected: func() sysfs.FS {
f, err := sysfs.NewRootFS(
[]sysfs.FS{sysfs.NewReadFS(sysfs.NewDirFS(".")), sysfs.NewDirFS("/tmp")},
[]string{"/", "/tmp"},
)
require.NoError(t, err)
return f
}(),
},
}
for _, tt := range tests {
tc := tt
t.Run(tc.name, func(t *testing.T) {
sysCtx, err := tc.input.(*fsConfig).toFS()
require.NoError(t, err)
require.Equal(t, tc.expected, sysCtx)
})
}
}
func TestFSConfig_Errors(t *testing.T) {
tests := []struct {
name string
input FSConfig
expectedErr string
}{
{
name: "multi-level path not yet supported",
input: NewFSConfig().WithDirMount(".", "/usr/bin"),
expectedErr: "only single-level guest paths allowed: [.:/usr/bin]",
},
}
for _, tt := range tests {
tc := tt
t.Run(tc.name, func(t *testing.T) {
_, err := tc.input.(*fsConfig).toFS()
require.EqualError(t, err, tc.expectedErr)
})
}
}
func TestFSConfig_clone(t *testing.T) {
fc := NewFSConfig().(*fsConfig)
fc.guestPathToFS["/"] = 0
cloned := fc.clone()
// Make post-clone changes
fc.guestPaths = []string{"/"}
fc.guestPathToFS["/"] = 1
// Ensure the guestPathToFS map is not shared
require.Equal(t, map[string]int{"/": 1}, fc.guestPathToFS)
require.Equal(t, map[string]int{"/": 0}, cloned.guestPathToFS)
// Ensure the guestPaths slice is not shared
require.Zero(t, len(cloned.guestPaths))
}