fix: filesystem error when creating long filename (#1240)

pkg/util/path_test.go

@@ -244,6 +244,81 @@ func TestReplaceInvalidFilename(t *testing.T) {
 	}
 }
 
+// TestSafeFilename tests the combined filename sanitization functionality
+func TestSafeFilename(t *testing.T) {
+	tests := []struct {
+		name     string
+		filename string
+		want     string
+	}{
+		{
+			name:     "short filename - no changes needed",
+			filename: "test.txt",
+			want:     "test.txt",
+		},
+		{
+			name:     "empty filename",
+			filename: "",
+			want:     "",
+		},
+		{
+			name:     "invalid chars only",
+			filename: "te/st:file.txt",
+			want:     "te_st_file.txt",
+		},
+		{
+			name:     "long filename only",
+			filename: "this_is_a_very_long_filename_that_exceeds_the_maximum_allowed_length_and_should_be_truncated_properly.txt",
+			want:     "this_is_a_very_long_filename_that_exceeds_the_maximum_allowed_length_and_should_be_truncated_pro.txt",
+		},
+		{
+			name:     "both invalid chars and too long",
+			filename: "path/to/very:long*filename?that<exceeds>filesystem|limits_and_has_invalid_characters_everywhere.pdf",
+			want:     "path_to_very_long*filename?that<exceeds>filesystem|limits_and_has_invalid_characters_everywhere.pdf",
+		},
+		{
+			name:     "unicode with invalid chars and truncation",
+			filename: "测试/文件名:非常长的中文文件名_需要被截断_这是一个测试用的超长文件名.pdf",
+			want:     "测试_文件名_非常长的中文文件名_需要被截断_这是一个测试用的超长文.pdf",
+		},
+		{
+			name:     "hidden file with truncation",
+			filename: ".gitignore_with_very_long_name_that_needs_truncation_and_more_characters_to_exceed_the_maximum_length",
+			want:     ".gitignore_with_very_long_name_that_needs_truncation_and_more_characters_to_exceed_the_maximum_lengt",
+		},
+		{
+			name:     "multiple dots and invalid chars",
+			filename: "archive/tar.gz.backup:old.txt",
+			want:     "archive_tar.gz.backup_old.txt",
+		},
+		{
+			name:     "extension longer than reasonable",
+			filename: "test.verylongextensionthatshouldnotbetreatedasextension_with_more_characters_to_exceed_maximum_length",
+			want:     "test.verylongextensionthatshouldnotbetreatedasextension_with_more_characters_to_exceed_maximum_lengt",
+		},
+		{
+			name:     "filename with spaces and invalid chars",
+			filename: "my document/with:spaces and a very long name that needs to be truncated because it exceeds the maximum length.docx",
+			want:     "my document_with_spaces and a very long name that needs to be truncated because it exceeds the .docx",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := SafeFilename(tt.filename)
+			if got != tt.want {
+				t.Errorf("SafeFilename() = %q (len=%d), want %q (len=%d)",
+					got, len(got), tt.want, len(tt.want))
+			}
+			// Verify result doesn't exceed MaxFilenameLength
+			if len(got) > MaxFilenameLength {
+				t.Errorf("SafeFilename() result length %d exceeds MaxFilenameLength %d",
+					len(got), MaxFilenameLength)
+			}
+		})
+	}
+}
+
 func TestReplacePathPlaceholders(t *testing.T) {
 	now := time.Now()
 	year := fmt.Sprintf("%d", now.Year())
@@ -315,3 +390,107 @@ func TestReplacePathPlaceholders(t *testing.T) {
 		})
 	}
 }
+
+// TestTruncateFilename tests the filename truncation functionality
+func TestTruncateFilename(t *testing.T) {
+	tests := []struct {
+		name      string
+		filename  string
+		maxLength int
+		want      string
+	}{
+		{
+			name:      "short filename - no truncation",
+			filename:  "test.txt",
+			maxLength: 100,
+			want:      "test.txt",
+		},
+		{
+			name:      "filename at exact limit",
+			filename:  "abcdefghij.txt", // 14 chars
+			maxLength: 14,
+			want:      "abcdefghij.txt",
+		},
+		{
+			name:      "long filename with extension - truncate base",
+			filename:  "this_is_a_very_long_filename_that_exceeds_the_maximum_allowed_length_and_should_be_truncated_properly.txt",
+			maxLength: 100,
+			want:      "this_is_a_very_long_filename_that_exceeds_the_maximum_allowed_length_and_should_be_truncated_pro.txt",
+		},
+		{
+			name:      "long filename without extension",
+			filename:  "this_is_a_very_long_filename_without_extension_that_exceeds_maximum_length_and_needs_truncation",
+			maxLength: 100,
+			want:      "this_is_a_very_long_filename_without_extension_that_exceeds_maximum_length_and_needs_truncation",
+		},
+		{
+			name:      "filename with multiple dots",
+			filename:  "archive.tar.gz.backup.old.file.with.many.dots.txt",
+			maxLength: 30,
+			want:      "archive.tar.gz.backup.old..txt", // Preserves last extension
+		},
+		{
+			name:      "hidden file (starts with dot)",
+			filename:  ".gitignore_with_very_long_name_that_needs_truncation",
+			maxLength: 30,
+			want:      ".gitignore_with_very_long_name",
+		},
+		{
+			name:      "only extension (no base name)",
+			filename:  ".txt",
+			maxLength: 100,
+			want:      ".txt",
+		},
+		{
+			name:      "unicode characters in filename",
+			filename:  "测试文件名_非常长的中文文件名_需要被截断_这是一个测试用的超长文件名.pdf",
+			maxLength: 50,
+			want:      "测试文件名_非常长的中文文件名_.pdf", // Truncated at byte boundary, preserving UTF-8
+		},
+		{
+			name:      "extension longer than reasonable (>20 chars)",
+			filename:  "test.verylongextensionthatshouldnotbetreatedasextension",
+			maxLength: 30,
+			want:      "test.verylongextensionthatshou",
+		},
+		{
+			name:      "very short max length with extension",
+			filename:  "document.pdf",
+			maxLength: 10,
+			want:      "docume.pdf",
+		},
+		{
+			name:      "maxLength smaller than extension",
+			filename:  "test.pdf",
+			maxLength: 3,
+			want:      "tes",
+		},
+		{
+			name:      "empty filename",
+			filename:  "",
+			maxLength: 100,
+			want:      "",
+		},
+		{
+			name:      "filename with spaces",
+			filename:  "my document with spaces and a very long name that needs to be truncated.docx",
+			maxLength: 50,
+			want:      "my document with spaces and a very long name .docx",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := TruncateFilename(tt.filename, tt.maxLength)
+			if got != tt.want {
+				t.Errorf("TruncateFilename() = %q (len=%d), want %q (len=%d)",
+					got, len(got), tt.want, len(tt.want))
+			}
+			// Verify result doesn't exceed maxLength
+			if len(got) > tt.maxLength {
+				t.Errorf("TruncateFilename() result length %d exceeds maxLength %d",
+					len(got), tt.maxLength)
+			}
+		})
+	}
+}