util/exists_test.go

package util

import (
	"os"
	"path/filepath"
	"testing"
)

func TestFileExistsAndDirExists(t *testing.T) {
	root := t.TempDir()

	file := filepath.Join(root, "a-file")
	if err := os.WriteFile(file, []byte("contents"), 0644); err != nil {
		t.Fatalf("could not write the test file: %v", err)
	}

	directory := filepath.Join(root, "a-directory")
	if err := os.Mkdir(directory, 0755); err != nil {
		t.Fatalf("could not make the test directory: %v", err)
	}

	linkToFile := filepath.Join(root, "link-to-file")
	if err := os.Symlink(file, linkToFile); err != nil {
		t.Fatalf("could not make the test link: %v", err)
	}

	brokenLink := filepath.Join(root, "broken-link")
	if err := os.Symlink(filepath.Join(root, "nothing-here"), brokenLink); err != nil {
		t.Fatalf("could not make the broken test link: %v", err)
	}

	tests := []struct {
		name          string
		path          string
		expectedFile  bool
		expectedIsDir bool
	}{
		{"a regular file", file, true, false},
		{"a directory", directory, false, true},
		{"a link to a file", linkToFile, true, false},
		{"a link to nothing", brokenLink, false, false},
		{"a path that is not there", filepath.Join(root, "missing"), false, false},
		{"a path whose parent is not there", filepath.Join(root, "missing", "deeper"), false, false},
		{"the empty path", "", false, false},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			if got := FileExists(test.path); got != test.expectedFile {
				t.Errorf("FileExists: expected %v got %v", test.expectedFile, got)
			}
			if got := DirExists(test.path); got != test.expectedIsDir {
				t.Errorf("DirExists: expected %v got %v", test.expectedIsDir, got)
			}
		})
	}
}