Add Files action to template context. (closes #1198) (#1226)

* Add Files action to template context. (#1198)

* Fixes to testFiles().

- Set os.ModePerm on directories created during test.
- Use filepath.Join() to create directory path.
- Use Fatalf, not Fatal.

* Make additional fixes to test cases.

* Fix test cases to use correct path format.

Dir.Open() in net/http requires '/'-separated paths while
filepath.Join() may produce paths with different separator.

* Remove directory created by test at end of loop.

* Close the FileSystem before returning.

* Initialize names slice to the number of entries.

Also, do not call os.RemoveAll() unless the path to the directory
is a valid one.

caddyhttp/httpserver/context.go

@@ -288,3 +288,33 @@ func (c Context) Map(values ...interface{}) (map[string]interface{}, error) {
 	}
 	return dict, nil
 }
+
+// Files reads and returns a slice of names from the given directory
+// relative to the root of Context c.
+func (c Context) Files(name string) ([]string, error) {
+	dir, err := c.Root.Open(path.Clean(name))
+	if err != nil {
+		return nil, err
+	}
+	defer dir.Close()
+
+	stat, err := dir.Stat()
+	if err != nil {
+		return nil, err
+	}
+	if !stat.IsDir() {
+		return nil, fmt.Errorf("%v is not a directory", name)
+	}
+
+	dirInfo, err := dir.Readdir(0)
+	if err != nil {
+		return nil, err
+	}
+
+	names := make([]string, len(dirInfo))
+	for i, fileInfo := range dirInfo {
+		names[i] = fileInfo.Name()
+	}
+
+	return names, nil
+}

caddyhttp/httpserver/context_test.go

@@ -8,6 +8,7 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"reflect"
 	"strings"
 	"testing"
 	"time"
@@ -684,3 +685,97 @@ func TestTemplates(t *testing.T) {
 		}
 	}
 }
+
+func TestFiles(t *testing.T) {
+	tests := []struct {
+		fileNames []string
+		inputBase string
+		shouldErr bool
+		verifyErr func(error) bool
+	}{
+		// Test 1 - directory and files exist
+		{
+			fileNames: []string{"file1", "file2"},
+			shouldErr: false,
+		},
+		// Test 2 - directory exists, no files
+		{
+			fileNames: []string{},
+			shouldErr: false,
+		},
+		// Test 3 - file or directory does not exist
+		{
+			fileNames: nil,
+			inputBase: "doesNotExist",
+			shouldErr: true,
+			verifyErr: os.IsNotExist,
+		},
+		// Test 4 - directory and files exist, but path to a file
+		{
+			fileNames: []string{"file1", "file2"},
+			inputBase: "file1",
+			shouldErr: true,
+			verifyErr: func(err error) bool {
+				return strings.HasSuffix(err.Error(), "is not a directory")
+			},
+		},
+		// Test 5 - try to leave Context Root
+		{
+			fileNames: nil,
+			inputBase: filepath.Join("..", "..", "..", "..", "..", "etc"),
+			shouldErr: true,
+			verifyErr: os.IsNotExist,
+		},
+	}
+
+	for i, test := range tests {
+		context := getContextOrFail(t)
+		testPrefix := getTestPrefix(i + 1)
+		var dirPath string
+		var err error
+
+		// Create directory / files from test case.
+		if test.fileNames != nil {
+			dirPath, err = ioutil.TempDir(fmt.Sprintf("%s", context.Root), "caddy_test")
+			if err != nil {
+				t.Fatalf(testPrefix+"Expected no error creating directory, got: '%s'", err.Error())
+			}
+
+			for _, name := range test.fileNames {
+				absFilePath := filepath.Join(dirPath, name)
+				if err = ioutil.WriteFile(absFilePath, []byte(""), os.ModePerm); err != nil {
+					t.Fatalf(testPrefix+"Expected no error creating file, got: '%s'", err.Error())
+				}
+			}
+		}
+
+		// Perform test case.
+		input := filepath.ToSlash(filepath.Join(filepath.Base(dirPath), test.inputBase))
+		actual, err := context.Files(input)
+		if err != nil {
+			if !test.shouldErr {
+				t.Errorf(testPrefix+"Expected no error, got: '%s'", err.Error())
+			} else if !test.verifyErr(err) {
+				t.Errorf(testPrefix+"Could not verify error content, got: '%s'", err.Error())
+			}
+		} else if test.shouldErr {
+			t.Errorf(testPrefix + "Expected error but had none")
+		} else {
+			numFiles := len(test.fileNames)
+			// reflect.DeepEqual does not consider two empty slices to be equal
+			if numFiles == 0 && len(actual) != 0 {
+				t.Errorf(testPrefix+"Expected files %v, got: %v",
+					test.fileNames, actual)
+			} else if numFiles > 0 && !reflect.DeepEqual(test.fileNames, actual) {
+				t.Errorf(testPrefix+"Expected files %v, got: %v",
+					test.fileNames, actual)
+			}
+		}
+
+		if dirPath != "" {
+			if err := os.RemoveAll(dirPath); err != nil && !os.IsNotExist(err) {
+				t.Fatalf(testPrefix+"Expected no error removing directory, got: '%s'", err.Error())
+			}
+		}
+	}
+}