wip: some more drastic refactoring

fs_test.go

@@ -0,0 +1,131 @@
+package golden
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMkdirAll(t *testing.T) {
+	tempDir := t.TempDir()
+
+	tests := []struct {
+		name    string
+		path    string
+		perm    os.FileMode
+		wantErr bool
+	}{
+		{"create new dir", "newdir", 0o755, false},
+		{"create nested dirs", "nested/dir/structure", 0o755, false},
+		{"invalid path", string([]byte{0, 0}), 0o755, true},
+	}
+
+	fs := NewFS()
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			path := filepath.Join(tempDir, tt.path)
+			err := fs.MkdirAll(path, tt.perm)
+
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				_, err := os.Stat(path)
+				assert.NoError(t, err)
+			}
+		})
+	}
+}
+
+func TestReadFile(t *testing.T) {
+	tempDir := t.TempDir()
+
+	sampleFilePath := filepath.Join(tempDir, "sample.txt")
+	sampleContent := []byte("Hello, world!")
+	err := os.WriteFile(sampleFilePath, sampleContent, 0o600)
+	require.NoError(t, err)
+
+	tests := []struct {
+		name     string
+		filename string
+		want     []byte
+		wantErr  bool
+	}{
+		{"read existing file", sampleFilePath, sampleContent, false},
+		{"file does not exist", "nonexistent.txt", nil, true},
+	}
+
+	fs := NewFS()
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := fs.ReadFile(tt.filename)
+
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, string(tt.want), string(got))
+			}
+		})
+	}
+}
+
+func TestWriteFile(t *testing.T) {
+	tempDir := t.TempDir()
+
+	tests := []struct {
+		name     string
+		filename string
+		data     []byte
+		perm     os.FileMode
+		wantErr  bool
+	}{
+		{
+			"write to new file",
+			"newfile.txt",
+			[]byte("new content"),
+			0o644,
+			false,
+		},
+		{
+			"overwrite existing file",
+			"existing.txt",
+			[]byte("overwritten content"),
+			0o644,
+			false,
+		},
+		{
+			"invalid filename",
+			string([]byte{0, 0}),
+			[]byte("invalid filename"),
+			0o644,
+			true,
+		},
+		{
+			"non-existent directory",
+			"nonexistentdir/newfile.txt",
+			[]byte("this will fail"),
+			0o644,
+			true,
+		},
+	}
+
+	fs := NewFS()
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			filePath := filepath.Join(tempDir, tt.filename)
+			err := fs.WriteFile(filePath, tt.data, tt.perm)
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				content, err := os.ReadFile(filePath)
+				assert.NoError(t, err)
+				assert.Equal(t, tt.data, content)
+			}
+		})
+	}
+}