Improve memory medium metadata

io.go

@@ -374,6 +374,7 @@ func (medium *MemoryMedium) Open(path string) (fs.File, error) {
 		name:    core.PathBase(path),
 		content: []byte(content),
 		mode:    medium.fileMode(path),
+		modTime: medium.modificationTime(path),
 	}, nil
 }
 
@@ -410,10 +411,11 @@ type MemoryFile struct {
 	content []byte
 	offset  int64
 	mode    fs.FileMode
+	modTime time.Time
 }
 
 func (file *MemoryFile) Stat() (fs.FileInfo, error) {
-	return NewFileInfo(file.name, int64(len(file.content)), file.mode, time.Time{}, false), nil
+	return NewFileInfo(file.name, int64(len(file.content)), file.mode, file.modTime, false), nil
 }
 
 func (file *MemoryFile) Read(buffer []byte) (int, error) {
@@ -457,6 +459,13 @@ func (medium *MemoryMedium) fileMode(path string) fs.FileMode {
 	return 0644
 }
 
+func (medium *MemoryMedium) modificationTime(path string) time.Time {
+	if modTime, ok := medium.modificationTimes[path]; ok {
+		return modTime
+	}
+	return time.Time{}
+}
+
 func (medium *MemoryMedium) List(path string) ([]fs.DirEntry, error) {
 	if _, ok := medium.directories[path]; !ok {
 		hasChildren := false
@@ -518,7 +527,7 @@ func (medium *MemoryMedium) List(path string) ([]fs.DirEntry, error) {
 				rest,
 				false,
 				medium.fileMode(filePath),
-				NewFileInfo(rest, int64(len(content)), medium.fileMode(filePath), time.Time{}, false),
+				NewFileInfo(rest, int64(len(content)), medium.fileMode(filePath), medium.modificationTime(filePath), false),
 			))
 		}
 	}

medium_test.go

@@ -234,6 +234,9 @@ func TestMemoryMedium_StreamAndFSHelpers_Good(t *testing.T) {
 	require.NoError(t, memoryMedium.EnsureDir("dir"))
 	require.NoError(t, memoryMedium.Write("dir/file.txt", "alpha"))
 
+	statInfo, err := memoryMedium.Stat("dir/file.txt")
+	require.NoError(t, err)
+
 	file, err := memoryMedium.Open("dir/file.txt")
 	require.NoError(t, err)
 
@@ -242,7 +245,7 @@ func TestMemoryMedium_StreamAndFSHelpers_Good(t *testing.T) {
 	assert.Equal(t, "file.txt", info.Name())
 	assert.Equal(t, int64(5), info.Size())
 	assert.Equal(t, fs.FileMode(0644), info.Mode())
-	assert.True(t, info.ModTime().IsZero())
+	assert.Equal(t, statInfo.ModTime(), info.ModTime())
 	assert.False(t, info.IsDir())
 	assert.Nil(t, info.Sys())
 
@@ -263,6 +266,7 @@ func TestMemoryMedium_StreamAndFSHelpers_Good(t *testing.T) {
 	assert.Equal(t, "file.txt", entryInfo.Name())
 	assert.Equal(t, int64(5), entryInfo.Size())
 	assert.Equal(t, fs.FileMode(0644), entryInfo.Mode())
+	assert.Equal(t, statInfo.ModTime(), entryInfo.ModTime())
 
 	writer, err := memoryMedium.Create("created.txt")
 	require.NoError(t, err)
@@ -290,9 +294,10 @@ func TestMemoryMedium_StreamAndFSHelpers_Good(t *testing.T) {
 	require.NoError(t, writeStream.Close())
 
 	assert.Equal(t, "stream output", memoryMedium.fileContents["streamed.txt"])
-	statInfo, err := memoryMedium.Stat("streamed.txt")
+	statInfo, err = memoryMedium.Stat("streamed.txt")
 	require.NoError(t, err)
 	assert.Equal(t, fs.FileMode(0644), statInfo.Mode())
+	assert.False(t, statInfo.ModTime().IsZero())
 }
 
 func TestIO_Read_Good(t *testing.T) {