| 140 | }; |
| 141 | |
| 142 | const decodeMostlyUtf8 = (data: Uint8Array): string | null => { |
| 143 | const decoded = new TextDecoder("utf-8").decode(data); |
| 144 | let replacements = 0; |
| 145 | let nonAsciiSignals = 0; |
| 146 | |
| 147 | for (let i = 0; i < decoded.length; i++) { |
| 148 | const code = decoded.charCodeAt(i); |
| 149 | if (code === 0xfffd) { |
| 150 | replacements++; |
| 151 | } else if (code > 0x7f) { |
| 152 | nonAsciiSignals++; |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | if (nonAsciiSignals >= replacements * 4 && replacements > 0 && replacements <= 8) { |
| 157 | return decoded; |
| 158 | } |
| 159 | |
| 160 | return null; |
| 161 | }; |
| 162 | |
| 163 | const hasSuspiciousDecodedControlChars = (text: string): boolean => { |
| 164 | let controls = 0; |