From cb8b6bc2ffb05f108d9b406cfe7c598875181849 Mon Sep 17 00:00:00 2001
From: LandonTClipp <landonclipp@gmail.com>
Date: Mon, 7 Sep 2020 00:05:27 -0500
Subject: [PATCH 1/2] Make MemMapFs implement Lstater

---
 go.mod         |  1 +
 memmap.go      |  5 +++++
 memmap_test.go | 23 +++++++++++++++++++++++
 3 files changed, 29 insertions(+)

diff --git a/go.mod b/go.mod
index abe4fe1c..7966d4bd 100644
--- a/go.mod
+++ b/go.mod
@@ -2,6 +2,7 @@ module github.com/spf13/afero
 
 require (
 	github.com/pkg/sftp v1.10.1
+	github.com/stretchr/testify v1.4.0
 	golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586
 	golang.org/x/text v0.3.3
 )
diff --git a/memmap.go b/memmap.go
index bbcc2381..0fa95924 100644
--- a/memmap.go
+++ b/memmap.go
@@ -317,6 +317,11 @@ func (m *MemMapFs) Rename(oldname, newname string) error {
 	return nil
 }
 
+func (m *MemMapFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
+	fileInfo, err := m.Stat(name)
+	return fileInfo, false, err
+}
+
 func (m *MemMapFs) Stat(name string) (os.FileInfo, error) {
 	f, err := m.Open(name)
 	if err != nil {
diff --git a/memmap_test.go b/memmap_test.go
index 6ce742cb..25e7f09d 100644
--- a/memmap_test.go
+++ b/memmap_test.go
@@ -8,6 +8,9 @@ import (
 	"runtime"
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestNormalizePath(t *testing.T) {
@@ -650,3 +653,23 @@ func TestMemFsOpenFileModeIllegal(t *testing.T) {
 		t.Fatalf("should not be able to use OpenFile to set illegal mode: %s", info.Mode().String())
 	}
 }
+
+// LstatIfPossible should always return false, since MemMapFs does not
+// support symlinks.
+func TestMemFsLstatIfPossible(t *testing.T) {
+	t.Parallel()
+
+	fs := NewMemMapFs()
+
+	// We assert that fs implements Lstater
+	fsAsserted, ok := fs.(Lstater)
+	require.True(t, ok, "The filesytem does not implement Lstater")
+
+	file, err := fs.OpenFile("/a.txt", os.O_CREATE, 0o644)
+	require.NoError(t, err)
+	defer file.Close()
+
+	_, lstatCalled, err := fsAsserted.LstatIfPossible("/a.txt")
+	assert.NoError(t, err)
+	assert.False(t, lstatCalled)
+}

From bf960e8dcb8b0489801bb18444499d29c02a961d Mon Sep 17 00:00:00 2001
From: LandonTClipp <landonclipp@gmail.com>
Date: Sun, 13 Sep 2020 14:01:19 -0500
Subject: [PATCH 2/2] Removing use of testify

---
 go.mod         |  1 -
 memmap_test.go | 19 ++++++++++++-------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/go.mod b/go.mod
index 7966d4bd..abe4fe1c 100644
--- a/go.mod
+++ b/go.mod
@@ -2,7 +2,6 @@ module github.com/spf13/afero
 
 require (
 	github.com/pkg/sftp v1.10.1
-	github.com/stretchr/testify v1.4.0
 	golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586
 	golang.org/x/text v0.3.3
 )
diff --git a/memmap_test.go b/memmap_test.go
index 25e7f09d..476909d6 100644
--- a/memmap_test.go
+++ b/memmap_test.go
@@ -8,9 +8,6 @@ import (
 	"runtime"
 	"testing"
 	"time"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
 func TestNormalizePath(t *testing.T) {
@@ -663,13 +660,21 @@ func TestMemFsLstatIfPossible(t *testing.T) {
 
 	// We assert that fs implements Lstater
 	fsAsserted, ok := fs.(Lstater)
-	require.True(t, ok, "The filesytem does not implement Lstater")
+	if !ok {
+		t.Fatalf("The filesytem does not implement Lstater")
+	}
 
 	file, err := fs.OpenFile("/a.txt", os.O_CREATE, 0o644)
-	require.NoError(t, err)
+	if err != nil {
+		t.Fatalf("Error when opening file: %v", err)
+	}
 	defer file.Close()
 
 	_, lstatCalled, err := fsAsserted.LstatIfPossible("/a.txt")
-	assert.NoError(t, err)
-	assert.False(t, lstatCalled)
+	if err != nil {
+		t.Fatalf("Function returned err: %v", err)
+	}
+	if lstatCalled {
+		t.Fatalf("Function indicated lstat was called. This should never be true.")
+	}
 }