lib/memfs: sanitize the Root directory to fix refresh

In [MemFS.refresh], if the requested url is "/file1" and [Options.Root]
is ".", the path during refresh become "file1" and if passed to
[filepath.Dir] it will return ".".
This cause the loop on refresh never end because there is no PathNodes
equal with ".".

4 files changed, 249 insertions, 23 deletions

diff --git a/lib/memfs/internal/testdata/get_refresh_test.data b/lib/memfs/internal/testdata/get_refresh_test.data
index 1cf9b8cc..ce3e5d9e 100644
--- a/lib/memfs/internal/testdata/get_refresh_test.data
+++ b/lib/memfs/internal/testdata/get_refresh_test.data
@@ -2,10 +2,46 @@ Test Get that trigger refresh.
 The MemFS Options TryDirect must be set to true.
 If the input content is not set then the file will not be written.
 
->>> /dir-a/dir-b/file
-Content of file.
+<<< /
+{
+  "path": "/",
+  "name": "/",
+  "content_type": "",
+  "mode_string": "drwxr-xr-x",
+  "size": 0,
+  "is_dir": true,
+  "childs": []
+}
+
+>>> /file1
+Content of file1.
+
+<<< /file1
+{
+  "path": "/",
+  "name": "/",
+  "content_type": "",
+  "mode_string": "drwxr-xr-x",
+  "size": 0,
+  "is_dir": true,
+  "childs": [
+    {
+      "path": "/file1",
+      "name": "file1",
+      "content_type": "text/plain; charset=utf-8",
+      "mode_string": "-rw-------",
+      "size": 17,
+      "is_dir": false,
+      "content": "Q29udGVudCBvZiBmaWxlMS4=",
+      "childs": []
+    }
+  ]
+}
+
+>>> /dir-a/dir-b/file2
+Content of file2.
 
-<<< /dir-a/dir-b/file
+<<< /dir-a/dir-b/file2
 {
   "path": "/",
   "name": "/",
@@ -15,6 +51,16 @@ Content of file.
   "is_dir": true,
   "childs": [
     {
+      "path": "/file1",
+      "name": "file1",
+      "content_type": "text/plain; charset=utf-8",
+      "mode_string": "-rw-------",
+      "size": 17,
+      "is_dir": false,
+      "content": "Q29udGVudCBvZiBmaWxlMS4=",
+      "childs": []
+    },
+    {
       "path": "/dir-a",
       "name": "dir-a",
       "content_type": "",
@@ -31,13 +77,13 @@ Content of file.
           "is_dir": true,
           "childs": [
             {
-              "path": "/dir-a/dir-b/file",
-              "name": "file",
+              "path": "/dir-a/dir-b/file2",
+              "name": "file2",
               "content_type": "text/plain; charset=utf-8",
               "mode_string": "-rw-------",
-              "size": 16,
+              "size": 17,
               "is_dir": false,
-              "content": "Q29udGVudCBvZiBmaWxlLg==",
+              "content": "Q29udGVudCBvZiBmaWxlMi4=",
               "childs": []
             }
           ]
@@ -47,10 +93,10 @@ Content of file.
   ]
 }
 
->>> /dir-a/dir-b/file2
-Content of file2.
+>>> /dir-a/dir-b/file3
+Content of file3.
 
-<<< /dir-a/dir-b/file2
+<<< /dir-a/dir-b/file3
 {
   "path": "/",
   "name": "/",
@@ -60,6 +106,16 @@ Content of file2.
   "is_dir": true,
   "childs": [
     {
+      "path": "/file1",
+      "name": "file1",
+      "content_type": "text/plain; charset=utf-8",
+      "mode_string": "-rw-------",
+      "size": 17,
+      "is_dir": false,
+      "content": "Q29udGVudCBvZiBmaWxlMS4=",
+      "childs": []
+    },
+    {
       "path": "/dir-a",
       "name": "dir-a",
       "content_type": "",
@@ -76,23 +132,23 @@ Content of file2.
           "is_dir": true,
           "childs": [
             {
-              "path": "/dir-a/dir-b/file",
-              "name": "file",
+              "path": "/dir-a/dir-b/file2",
+              "name": "file2",
               "content_type": "text/plain; charset=utf-8",
               "mode_string": "-rw-------",
-              "size": 16,
+              "size": 17,
               "is_dir": false,
-              "content": "Q29udGVudCBvZiBmaWxlLg==",
+              "content": "Q29udGVudCBvZiBmaWxlMi4=",
               "childs": []
             },
             {
-              "path": "/dir-a/dir-b/file2",
-              "name": "file2",
+              "path": "/dir-a/dir-b/file3",
+              "name": "file3",
               "content_type": "text/plain; charset=utf-8",
               "mode_string": "-rw-------",
               "size": 17,
               "is_dir": false,
-              "content": "Q29udGVudCBvZiBmaWxlMi4=",
+              "content": "Q29udGVudCBvZiBmaWxlMy4=",
               "childs": []
             }
           ]
diff --git a/lib/memfs/memfs.go b/lib/memfs/memfs.go
index 6ef40c2d..4ac9eba0 100644
--- a/lib/memfs/memfs.go
+++ b/lib/memfs/memfs.go
@@ -637,6 +637,13 @@ out:
 func (mfs *MemFS) refresh(url string) (node *Node, err error) {
 	syspath := filepath.Join(mfs.Root.SysPath, url)
 
+	if syspath[0] != '/' {
+		// When "." joined with url "/file", the syspath become
+		// "file" instead of "./file", this cause
+		// [strings.HasPrefix] return false.
+		syspath = `./` + syspath
+	}
+
 	if !strings.HasPrefix(syspath, mfs.Root.SysPath) {
 		return nil, fs.ErrNotExist
 	}
@@ -655,6 +662,11 @@ func (mfs *MemFS) refresh(url string) (node *Node, err error) {
 
 	for node == nil {
 		dir = filepath.Dir(dir)
+		if dir == `.` {
+			// On "./file" it will return ".".
+			node = mfs.Root
+			break
+		}
 		node = mfs.PathNodes.Get(dir)
 	}
 
diff --git a/lib/memfs/memfs_test.go b/lib/memfs/memfs_test.go
index 12651413..8275ea3b 100644
--- a/lib/memfs/memfs_test.go
+++ b/lib/memfs/memfs_test.go
@@ -65,11 +65,46 @@ func TestNew(t *testing.T) {
 		opts       Options
 	}
 
+	var dirTestdata = filepath.Join(_testWD, `testdata`)
+	var err error
+
+	err = os.Chdir(dirTestdata)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Cleanup(func() {
+		err = os.Chdir(_testWD)
+		if err != nil {
+			t.Fatal(err)
+		}
+	})
+
 	var afile = filepath.Join(_testWD, `testdata/index.html`)
 
 	var listCase = []testCase{{
-		desc:   "With empty dir",
-		expErr: "open : no such file or directory",
+		desc: `With empty dir`,
+		expMapKeys: []string{
+			`/`,
+			`/direct`,
+			`/direct/add`,
+			`/direct/add/file`,
+			`/direct/add/file2`,
+			`/exclude`,
+			`/exclude/dir`,
+			`/exclude/index-link.css`,
+			`/exclude/index-link.html`,
+			`/exclude/index-link.js`,
+			`/include`,
+			`/include/dir`,
+			`/include/index.css`,
+			`/include/index.html`,
+			`/include/index.js`,
+			`/index.css`,
+			`/index.html`,
+			`/index.js`,
+			`/plain`,
+		},
 	}, {
 		desc: "With file",
 		opts: Options{
@@ -79,7 +114,7 @@ func TestNew(t *testing.T) {
 	}, {
 		desc: "With directory",
 		opts: Options{
-			Root: filepath.Join(_testWD, "testdata"),
+			Root: dirTestdata,
 			Excludes: []string{
 				"memfs_generate.go$",
 				"direct$",
@@ -156,7 +191,6 @@ func TestNew(t *testing.T) {
 	var (
 		c   testCase
 		mfs *MemFS
-		err error
 	)
 	for _, c = range listCase {
 		t.Log(c.desc)
@@ -392,7 +426,7 @@ func TestMemFS_Get_refresh(t *testing.T) {
 	var (
 		tempDir = t.TempDir()
 		opts    = Options{
-			Root:      tempDir,
+			Root:      tempDir + `/`,
 			TryDirect: true,
 		}
 
@@ -405,9 +439,127 @@ func TestMemFS_Get_refresh(t *testing.T) {
 	}
 
 	var listCase = []testCase{{
-		filePath: `/dir-a/dir-b/file`,
+		filePath: `/file1`,
 	}, {
 		filePath: `/dir-a/dir-b/file2`,
+	}, {
+		filePath: `/dir-a/dir-b/file3`,
+	}}
+
+	var (
+		c       testCase
+		gotJSON bytes.Buffer
+	)
+	for _, c = range listCase {
+		var fullpath = filepath.Join(tempDir, c.filePath)
+
+		err = os.MkdirAll(filepath.Dir(fullpath), 0700)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		var expContent = tdata.Input[c.filePath]
+		if len(expContent) != 0 {
+			// Only create the file if content is set.
+			err = os.WriteFile(fullpath, expContent, 0600)
+			if err != nil {
+				t.Fatal(err)
+			}
+		}
+
+		// Try Get the file.
+
+		var (
+			tag      = c.filePath + `:error`
+			expError = string(tdata.Output[tag])
+			node     *Node
+		)
+
+		node, err = mfs.Get(c.filePath)
+		if err != nil {
+			test.Assert(t, tag, expError, err.Error())
+			continue
+		}
+
+		// Check the tree of MemFS.
+
+		var rawJSON []byte
+
+		rawJSON, err = mfs.Root.JSON(9999, true, false)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		gotJSON.Reset()
+		err = json.Indent(&gotJSON, rawJSON, ``, `  `)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		test.Assert(t, c.filePath+` content`, string(expContent), string(node.Content))
+
+		var expJSON = string(tdata.Output[c.filePath])
+		test.Assert(t, c.filePath+` JSON of memfs.Root`, expJSON, gotJSON.String())
+	}
+}
+
+// TestMemFS_Get_refresh_withDot test [MemFS.refresh] using "." as Root
+// directory.
+func TestMemFS_Get_refresh_withDot(t *testing.T) {
+	type testCase struct {
+		filePath string
+	}
+
+	var (
+		tdata *test.Data
+		err   error
+	)
+
+	tdata, err = test.LoadData(`internal/testdata/get_refresh_test.data`)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var (
+		tempDir = t.TempDir()
+		opts    = Options{
+			Root:      `.`,
+			TryDirect: true,
+		}
+		workDir string
+		mfs     *MemFS
+	)
+
+	workDir, err = os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = os.Chdir(tempDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Cleanup(func() {
+		err = os.Chdir(workDir)
+		if err != nil {
+			t.Logf(err.Error())
+		}
+	})
+
+	mfs, err = New(&opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var listCase = []testCase{{
+		filePath: `/`,
+	}, {
+		filePath: `/file1`,
+	}, {
+		filePath: `/dir-a/dir-b/file2`,
+	}, {
+		filePath: `/dir-a/dir-b/file3`,
 	}}
 
 	var (
diff --git a/lib/memfs/options.go b/lib/memfs/options.go
index cae701b2..0b415f5c 100644
--- a/lib/memfs/options.go
+++ b/lib/memfs/options.go
@@ -4,6 +4,8 @@
 
 package memfs
 
+import "strings"
+
 const (
 	defaultMaxFileSize = 1024 * 1024 * 5
 )
@@ -48,4 +50,8 @@ func (opts *Options) init() {
 	if opts.MaxFileSize == 0 {
 		opts.MaxFileSize = defaultMaxFileSize
 	}
+	opts.Root = strings.TrimSuffix(opts.Root, `/`)
+	if len(opts.Root) == 0 {
+		opts.Root = `.`
+	}
 }