让 lzma-native 变成可选依赖，并且在 xz 使用的时候判断依赖是否存在

Author: fengmk2

README.md

@@ -22,14 +22,20 @@ Currently supported:
 - gzip
 - tgz
 - zip
-- xz
+- xz (requires optional dependency `lzma-native`)
 
 ## Install
 
 ```bash
 npm install compressing
 ```
 
+For xz compression/decompression support, you need to install the optional dependency:
+
+```bash
+npm install lzma-native
+```
+
 ## Usage
 
 ### Compress a single file
@@ -323,6 +329,8 @@ XZ params:
 
 - opts.lzma - {Object} xz.FileStream uses lzma-native to compress, pass this param to control the behavior of lzma-native.
 
+__Note: xz compression/decompression requires the optional dependency `lzma-native`. If you try to use xz features without installing it, you'll get an error asking you to install it.__
+
 ### Stream
 
 The readable stream to compress anything as you need.

lib/xz/index.js

@@ -1,11 +1,55 @@
 'use strict';
 
 const utils = require('../utils');
-const XzFileStream = require('./file_stream');
-const XzUncompressStream = require('./uncompress_stream');
-
-exports.FileStream = XzFileStream;
-exports.UncompressStream = XzUncompressStream;
-exports.compressFile = utils.makeFileProcessFn(XzFileStream);
-exports.uncompress = utils.makeFileProcessFn(XzUncompressStream);
-exports.decompress = utils.makeFileProcessFn(XzUncompressStream);
+
+let XzFileStream;
+let XzUncompressStream;
+
+function checkDependency() {
+  try {
+    require('lzma-native');
+    return true;
+  } catch (err) {
+    return false;
+  }
+}
+
+function throwIfNoDependency() {
+  if (!checkDependency()) {
+    throw new Error('lzma-native is required for xz compression/decompression. Please install it with: npm install lzma-native');
+  }
+}
+
+// Lazy load the implementation
+function getImplementation() {
+  if (!XzFileStream) {
+    throwIfNoDependency();
+    XzFileStream = require('./file_stream');
+    XzUncompressStream = require('./uncompress_stream');
+  }
+  return { XzFileStream, XzUncompressStream };
+}
+
+exports.FileStream = function(opts) {
+  const { XzFileStream } = getImplementation();
+  return new XzFileStream(opts);
+};
+
+exports.UncompressStream = function(opts) {
+  const { XzUncompressStream } = getImplementation();
+  return new XzUncompressStream(opts);
+};
+
+exports.compressFile = function(source, dest, opts) {
+  throwIfNoDependency();
+  const { XzFileStream } = getImplementation();
+  return utils.makeFileProcessFn(XzFileStream)(source, dest, opts);
+};
+
+exports.uncompress = function(source, dest, opts) {
+  throwIfNoDependency();
+  const { XzUncompressStream } = getImplementation();
+  return utils.makeFileProcessFn(XzUncompressStream)(source, dest, opts);
+};
+
+exports.decompress = exports.uncompress;

lib/xz/uncompress_stream.js

@@ -45,6 +45,5 @@ class XzUncompressStream extends PassThrough {
     });
   }
 }
-}
 
 module.exports = XzUncompressStream;

package.json

@@ -42,14 +42,16 @@
     "flushwritable": "^1.0.0",
     "get-ready": "^1.0.0",
     "iconv-lite": "^0.5.0",
-    "lzma-native": "^8.0.5",
     "mkdirp": "^0.5.1",
     "pump": "^3.0.0",
     "streamifier": "^0.1.1",
     "tar-stream": "^1.5.2",
     "@eggjs/yauzl": "^2.11.0",
     "yazl": "^2.4.2"
   },
+  "optionalDependencies": {
+    "lzma-native": "^8.0.6"
+  },
   "devDependencies": {
     "@types/mocha": "10",
     "@types/node": "20",