From 1b48a934667faa1c87c591fc3839b953d4af02c1 Mon Sep 17 00:00:00 2001
From: Eric Hauser <ewhauser@gmail.com>
Date: Tue, 21 Jan 2025 20:11:45 -0700
Subject: [PATCH] fix(cli): unescape runfiles entries from manifest #799

---
 pkg/aspect/outputs/BUILD.bazel      |  1 +
 pkg/aspect/outputs/hash.go          |  3 ++-
 pkg/bazel/runfiles/BUILD.bazel      | 17 +++++++++++++++
 pkg/bazel/runfiles/runfiles.go      | 33 +++++++++++++++++++++++++++++
 pkg/bazel/runfiles/runfiles_test.go | 32 ++++++++++++++++++++++++++++
 5 files changed, 85 insertions(+), 1 deletion(-)
 create mode 100644 pkg/bazel/runfiles/BUILD.bazel
 create mode 100644 pkg/bazel/runfiles/runfiles.go
 create mode 100644 pkg/bazel/runfiles/runfiles_test.go

diff --git a/pkg/aspect/outputs/BUILD.bazel b/pkg/aspect/outputs/BUILD.bazel
index 33f61b8f1..65a438d24 100644
--- a/pkg/aspect/outputs/BUILD.bazel
+++ b/pkg/aspect/outputs/BUILD.bazel
@@ -11,6 +11,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//pkg/bazel",
+        "//pkg/bazel/runfiles",
         "//pkg/ioutils",
         "@com_github_alphadose_haxmap//:haxmap",
         "@com_github_rogpeppe_go_internal//dirhash",
diff --git a/pkg/aspect/outputs/hash.go b/pkg/aspect/outputs/hash.go
index 87e557815..8a2034747 100644
--- a/pkg/aspect/outputs/hash.go
+++ b/pkg/aspect/outputs/hash.go
@@ -32,6 +32,7 @@ import (
 
 	"github.com/alphadose/haxmap"
 	"github.com/aspect-build/aspect-cli/pkg/bazel"
+	r "github.com/aspect-build/aspect-cli/pkg/bazel/runfiles"
 	"github.com/rogpeppe/go-internal/dirhash"
 
 	concurrently "github.com/tejzpr/ordered-concurrently/v3"
@@ -73,7 +74,7 @@ func AddRunfilesHash(hashFiles map[string][]string, label string, manifestPath s
 		// execroot/path /some/absolute/path
 		entry := strings.Split(fileScanner.Text(), " ")
 		// key := entry[0]
-		abspath := entry[1]
+		abspath := r.Unescape(entry[1])
 		fileinfo, err := os.Stat(abspath)
 
 		if err != nil {
diff --git a/pkg/bazel/runfiles/BUILD.bazel b/pkg/bazel/runfiles/BUILD.bazel
new file mode 100644
index 000000000..1dfcbc061
--- /dev/null
+++ b/pkg/bazel/runfiles/BUILD.bazel
@@ -0,0 +1,17 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "runfiles",
+    srcs = ["runfiles.go"],
+    importpath = "github.com/aspect-build/aspect-cli/pkg/bazel/runfiles",
+    visibility = ["//visibility:public"],
+)
+
+go_test(
+    name = "runfiles_test",
+    srcs = ["runfiles_test.go"],
+    deps = [
+        ":runfiles",
+        "@com_github_stretchr_testify//require",
+    ],
+)
diff --git a/pkg/bazel/runfiles/runfiles.go b/pkg/bazel/runfiles/runfiles.go
new file mode 100644
index 000000000..ac15e82c5
--- /dev/null
+++ b/pkg/bazel/runfiles/runfiles.go
@@ -0,0 +1,33 @@
+package runfiles
+
+// Unescape the behavior of the C++ implementation
+// https://github.com/bazelbuild/bazel/blob/09c621e4cf5b968f4c6cdf905ab142d5961f9ddc/src/main/tools/build-runfiles/build-runfiles.cc#L76
+func Unescape(path string) string {
+	var result []rune
+	runes := []rune(path)
+
+	for i := 0; i < len(runes); i++ {
+		if runes[i] == '\\' && i+1 < len(runes) {
+			switch runes[i+1] {
+			case 's':
+				result = append(result, ' ')
+			case 'n':
+				result = append(result, '\n')
+			case 'b':
+				result = append(result, '\\')
+			default:
+				// For escaped backslash (\\), output single backslash
+				if runes[i+1] == '\\' {
+					result = append(result, '\\')
+				} else {
+					// For any other escaped character, preserve both the backslash and the character
+					result = append(result, '\\', runes[i+1])
+				}
+			}
+			i++ // Skip the escaped character
+		} else {
+			result = append(result, runes[i])
+		}
+	}
+	return string(result)
+}
diff --git a/pkg/bazel/runfiles/runfiles_test.go b/pkg/bazel/runfiles/runfiles_test.go
new file mode 100644
index 000000000..5c162314f
--- /dev/null
+++ b/pkg/bazel/runfiles/runfiles_test.go
@@ -0,0 +1,32 @@
+package runfiles_test
+
+import (
+	"github.com/aspect-build/aspect-cli/pkg/bazel/runfiles"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestUnescape(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{"hello\\sworld", "hello world"},
+		{"new\\nline", "new\nline"},
+		{"back\\bslash", "back\\slash"},
+		{"double\\\\slash", "double\\slash"},
+		{"raw\\xsequence", "raw\\xsequence"},
+		{"no\\", "no\\"}, // Handles trailing backslash
+		{"\\s\\n\\b", " \n\\"},
+		{"", ""},
+		{"normal text", "normal text"},
+		{"\\s\\s\\s", "   "},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			got := runfiles.Unescape(tt.input)
+			require.Equal(t, tt.expected, got)
+		})
+	}
+}