From 5d209e914ed24636b81e08ede31f4c1d63716fe9 Mon Sep 17 00:00:00 2001
From: Kelz <code@kelz.io>
Date: Thu, 3 Sep 2026 22:12:11 -0500
Subject: [PATCH] fix: create parent directory for zip entries lacking dir
 entries (closes #25)

Flat/unnested addon zips omit explicit directory entries for nested
paths, so os.Create() failed on the target file because its parent
directory was never created. MkdirAll the parent before creating the
file.
---
 pkg/curseforge/curseforge.go      |   4 ++
 pkg/curseforge/curseforge_test.go | 101 ++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+)
 create mode 100644 pkg/curseforge/curseforge_test.go

diff --git a/pkg/curseforge/curseforge.go b/pkg/curseforge/curseforge.go
index 793487a..23f3fb0 100644
--- a/pkg/curseforge/curseforge.go
+++ b/pkg/curseforge/curseforge.go
@@ -162,6 +162,10 @@ func (c *Client) InstallAddon(file File, dest string) error {
 		if zipFile.FileInfo().IsDir() {
 			os.MkdirAll(targetFilePath, zipFile.Mode())
 		} else {
+			if err := os.MkdirAll(filepath.Dir(targetFilePath), 0o755); err != nil {
+				return fmt.Errorf("Failed to create parent directory for target file: %w", err)
+			}
+
 			targetFile, err := os.Create(targetFilePath)
 			if err != nil {
 				return fmt.Errorf("Failed to create target file: %w", err)
diff --git a/pkg/curseforge/curseforge_test.go b/pkg/curseforge/curseforge_test.go
new file mode 100644
index 0000000..2dfdedf
--- /dev/null
+++ b/pkg/curseforge/curseforge_test.go
@@ -0,0 +1,101 @@
+package curseforge
+
+import (
+	"archive/zip"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+type testFile struct {
+	name    string
+	content string
+}
+
+func buildTestZip(t *testing.T, destPath string, testFiles []testFile, withDirEntries bool) {
+	t.Helper()
+
+	zf, err := os.Create(destPath)
+	if err != nil {
+		t.Fatalf("failed to create zip file: %v", err)
+	}
+	defer zf.Close()
+
+	zw := zip.NewWriter(zf)
+
+	if withDirEntries {
+		seen := map[string]bool{}
+		for _, file := range testFiles {
+			dir := filepath.Dir(file.name)
+			for dir != "." && dir != "/" && !seen[dir] {
+				seen[dir] = true
+				hdr := &zip.FileHeader{Name: dir + "/"}
+				hdr.SetMode(os.ModeDir | 0o755)
+				if _, err := zw.CreateHeader(hdr); err != nil {
+					t.Fatalf("failed to write dir entry %q: %v", dir, err)
+				}
+				dir = filepath.Dir(dir)
+			}
+		}
+	}
+
+	for _, file := range testFiles {
+		w, err := zw.Create(file.name)
+		if err != nil {
+			t.Fatalf("failed to create zip entry %q: %v", file.name, err)
+		}
+		if _, err := w.Write([]byte(file.content)); err != nil {
+			t.Fatalf("failed to write zip entry %q: %v", file.name, err)
+		}
+	}
+
+	if err := zw.Close(); err != nil {
+		t.Fatalf("failed to close zip writer: %v", err)
+	}
+}
+
+func TestClient_InstallAddon(t *testing.T) {
+	testFiles := []testFile{
+		{name: "MyAddon/MyAddon.toc", content: "toc-content"},
+		{name: "MyAddon/Libs/Lib.lua", content: "lib-content"},
+	}
+
+	tests := []struct {
+		name           string
+		withDirEntries bool
+	}{
+		{name: "flat zip without directory entries", withDirEntries: false},
+		{name: "zip with directory entries", withDirEntries: true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpDir := t.TempDir()
+			zipPath := filepath.Join(tmpDir, "addon.zip")
+			buildTestZip(t, zipPath, testFiles, tt.withDirEntries)
+
+			destDir := filepath.Join(tmpDir, "dest")
+			if err := os.MkdirAll(destDir, 0o755); err != nil {
+				t.Fatalf("failed to create dest dir: %v", err)
+			}
+
+			client := NewClient()
+			file := File{Location: zipPath}
+
+			if err := client.InstallAddon(file, destDir); err != nil {
+				t.Fatalf("InstallAddon returned an error: %v", err)
+			}
+
+			for _, file := range testFiles {
+				installedPath := filepath.Join(destDir, file.name)
+				got, err := os.ReadFile(installedPath)
+				if err != nil {
+					t.Fatalf("expected file %q to exist: %v", installedPath, err)
+				}
+				if string(got) != file.content {
+					t.Errorf("file %q content = %q, want %q", installedPath, got, file.content)
+				}
+			}
+		})
+	}
+}