1 files changed, 187 insertions, 0 deletions
diff --git a/cli/internal/globby/globby.go b/cli/internal/globby/globby.go
new file mode 100644
index 0000000..14c40d9
--- /dev/null
+++ b/cli/internal/globby/globby.go
@@ -0,0 +1,187 @@
+package globby
+
+import (
+	"fmt"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	iofs "io/fs"
+
+	"github.com/vercel/turbo/cli/internal/fs"
+
+	"github.com/vercel/turbo/cli/internal/doublestar"
+	"github.com/vercel/turbo/cli/internal/util"
+)
+
+// GlobAll returns an array of files and folders that match the specified set of glob patterns.
+// The returned files and folders are absolute paths, assuming that basePath is an absolute path.
+func GlobAll(basePath string, includePatterns []string, excludePatterns []string) ([]string, error) {
+	fsys := fs.CreateDirFSAtRoot(basePath)
+	fsysRoot := fs.GetDirFSRootPath(fsys)
+	output, err := globAllFs(fsys, fsysRoot, basePath, includePatterns, excludePatterns)
+
+	// Because this is coming out of a map output is in no way ordered.
+	// Sorting will put the files in a depth-first order.
+	sort.Strings(output)
+	return output, err
+}
+
+// GlobFiles returns an array of files that match the specified set of glob patterns.
+// The return files are absolute paths, assuming that basePath is an absolute path.
+func GlobFiles(basePath string, includePatterns []string, excludePatterns []string) ([]string, error) {
+	fsys := fs.CreateDirFSAtRoot(basePath)
+	fsysRoot := fs.GetDirFSRootPath(fsys)
+	output, err := globFilesFs(fsys, fsysRoot, basePath, includePatterns, excludePatterns)
+
+	// Because this is coming out of a map output is in no way ordered.
+	// Sorting will put the files in a depth-first order.
+	sort.Strings(output)
+	return output, err
+}
+
+// checkRelativePath ensures that the the requested file path is a child of `from`.
+func checkRelativePath(from string, to string) error {
+	relativePath, err := filepath.Rel(from, to)
+
+	if err != nil {
+		return err
+	}
+
+	if strings.HasPrefix(relativePath, "..") {
+		return fmt.Errorf("the path you are attempting to specify (%s) is outside of the root", to)
+	}
+
+	return nil
+}
+
+// globFilesFs searches the specified file system to enumerate all files to include.
+func globFilesFs(fsys iofs.FS, fsysRoot string, basePath string, includePatterns []string, excludePatterns []string) ([]string, error) {
+	return globWalkFs(fsys, fsysRoot, basePath, includePatterns, excludePatterns, false)
+}
+
+// globAllFs searches the specified file system to enumerate all files to include.
+func globAllFs(fsys iofs.FS, fsysRoot string, basePath string, includePatterns []string, excludePatterns []string) ([]string, error) {
+	return globWalkFs(fsys, fsysRoot, basePath, includePatterns, excludePatterns, true)
+}
+
+// globWalkFs searches the specified file system to enumerate all files and folders to include.
+func globWalkFs(fsys iofs.FS, fsysRoot string, basePath string, includePatterns []string, excludePatterns []string, includeDirs bool) ([]string, error) {
+	var processedIncludes []string
+	var processedExcludes []string
+	result := make(util.Set)
+
+	for _, includePattern := range includePatterns {
+		includePath := filepath.Join(basePath, includePattern)
+		err := checkRelativePath(basePath, includePath)
+
+		if err != nil {
+			return nil, err
+		}
+
+		// fs.FS paths may not include leading separators. Calculate the
+		// correct path for this relative to the filesystem root.
+		// This will not error as it follows the call to checkRelativePath.
+		iofsRelativePath, _ := fs.IofsRelativePath(fsysRoot, includePath)
+
+		// Includes only operate on files.
+		processedIncludes = append(processedIncludes, iofsRelativePath)
+	}
+
+	for _, excludePattern := range excludePatterns {
+		excludePath := filepath.Join(basePath, excludePattern)
+		err := checkRelativePath(basePath, excludePath)
+
+		if err != nil {
+			return nil, err
+		}
+
+		// fs.FS paths may not include leading separators. Calculate the
+		// correct path for this relative to the filesystem root.
+		// This will not error as it follows the call to checkRelativePath.
+		iofsRelativePath, _ := fs.IofsRelativePath(fsysRoot, excludePath)
+
+		// In case this is a file pattern and not a directory, add the exact pattern.
+		// In the event that the user has already specified /**,
+		if !strings.HasSuffix(iofsRelativePath, string(filepath.Separator)+"**") {
+			processedExcludes = append(processedExcludes, iofsRelativePath)
+		}
+		// TODO: we need to either document or change this behavior
+		// Excludes operate on entire folders, so we also exclude everything under this in case it represents a directory
+		processedExcludes = append(processedExcludes, filepath.Join(iofsRelativePath, "**"))
+	}
+
+	// We start from a naive includePattern
+	includePattern := ""
+	includeCount := len(processedIncludes)
+
+	// Do not use alternation if unnecessary.
+	if includeCount == 1 {
+		includePattern = processedIncludes[0]
+	} else if includeCount > 1 {
+		// We use alternation from the very root of the path. This avoids fs.Stat of the basePath.
+		includePattern = "{" + strings.Join(processedIncludes, ",") + "}"
+	}
+
+	// We start with an empty string excludePattern which we only use if excludeCount > 0.
+	excludePattern := ""
+	excludeCount := len(processedExcludes)
+
+	// Do not use alternation if unnecessary.
+	if excludeCount == 1 {
+		excludePattern = processedExcludes[0]
+	} else if excludeCount > 1 {
+		// We use alternation from the very root of the path. This avoids fs.Stat of the basePath.
+		excludePattern = "{" + strings.Join(processedExcludes, ",") + "}"
+	}
+
+	// GlobWalk expects that everything uses Unix path conventions.
+	includePattern = filepath.ToSlash(includePattern)
+	excludePattern = filepath.ToSlash(excludePattern)
+
+	err := doublestar.GlobWalk(fsys, includePattern, func(path string, dirEntry iofs.DirEntry) error {
+		if !includeDirs && dirEntry.IsDir() {
+			return nil
+		}
+
+		// All files that are returned by doublestar.GlobWalk are relative to
+		// the fsys root. Go, however, has decided that `fs.FS` filesystems do
+		// not address the root of the file system using `/` and instead use
+		// paths without leading separators.
+		//
+		// We need to track where the `fsys` root is so that when we hand paths back
+		// we hand them back as the path addressable in the actual OS filesystem.
+		//
+		// As a consequence, when processing, we need to *restore* the original
+		// root to the file path after returning. This works because when we create
+		// the `os.dirFS` filesystem we do so at the root of the current volume.
+		if excludeCount == 0 {
+			// Reconstruct via string concatenation since the root is already pre-composed.
+			result.Add(fsysRoot + path)
+			return nil
+		}
+
+		isExcluded, err := doublestar.Match(excludePattern, filepath.ToSlash(path))
+		if err != nil {
+			return err
+		}
+
+		if !isExcluded {
+			// Reconstruct via string concatenation since the root is already pre-composed.
+			result.Add(fsysRoot + path)
+		}
+
+		return nil
+	})
+
+	// GlobWalk threw an error.
+	if err != nil {
+		return nil, err
+	}
+
+	// Never actually capture the root folder.
+	// This is a risk because of how we rework the globs.
+	result.Delete(strings.TrimSuffix(basePath, "/"))
+
+	return result.UnsafeListOfStrings(), nil
+}