fix(runtime): polyfill PDF.js Map APIs for older WebViews

2026-10-18 13:16:32 +08:00
parent b13b71b27c
commit e84906652e
4 changed files with 169 additions and 0 deletions
@@ -0,0 +1,67 @@
+import { readFileSync, writeFileSync } from 'node:fs';
+import { join, resolve } from 'node:path';
+import { pathToFileURL } from 'node:url';
+
+// Executed independently in the page and the embedded PDF worker.
+export function installMapCompat() {
+  'use strict';
+  const { has, get, set } = Map.prototype;
+  if (typeof Map.prototype.getOrInsertComputed !== 'function') {
+    Object.defineProperty(Map.prototype, 'getOrInsertComputed', {
+      configurable: true, writable: true,
+      value: function getOrInsertComputed(key, callback) {
+        const exists = has.call(this, key);
+        if (typeof callback !== 'function') throw new TypeError('callback must be callable');
+        if (exists) return get.call(this, key);
+        if (key === 0) key = 0; // Canonicalize -0 before invoking callback.
+        const value = callback(key);
+        set.call(this, key, value);
+        return value;
+      },
+    });
+  }
+  if (typeof Map.prototype.getOrInsert !== 'function') {
+    Object.defineProperty(Map.prototype, 'getOrInsert', {
+      configurable: true, writable: true,
+      value: function getOrInsert(key, value) {
+        if (has.call(this, key)) return get.call(this, key);
+        set.call(this, key, value);
+        return value;
+      },
+    });
+  }
+}
+
+const newline = String.fromCharCode(10);
+export const prelude = '/* dsh-mgr: webview-map-compat */' + newline + '(' + installMapCompat.toString() + ')();' + newline;
+export const workerPrefix = 'var _dsh_pdf_worker_default = ';
+
+export function patchPdfClient(source, version, pluginVersion) {
+  if (version !== '0.2.1-rc.2' || pluginVersion !== version) {
+    throw new Error('unsupported DSH/documentpreview version for WebView compatibility patch');
+  }
+  if (source.includes('dsh-mgr: webview-map-compat')) throw new Error('WebView compatibility patch already applied');
+  const lines = source.split(newline);
+  const targets = lines.filter(line => line.trimStart().startsWith(workerPrefix));
+  if (targets.length !== 1 || !source.includes('this.#methodPromises.getOrInsertComputed(')) {
+    throw new Error('expected PDF.js method cache and exactly one embedded worker');
+  }
+  const target = targets[0];
+  // Preserve the JS string literal verbatim (it can contain non-JSON escapes).
+  const worker = target.trim().slice(workerPrefix.length, -1);
+  if (!worker.includes('getOrInsertComputed') || !worker.includes('pdfjsVersion = 6.3.289')) {
+    throw new Error('unexpected embedded PDF.js worker');
+  }
+  // A page-level polyfill cannot cross into the worker realm.
+  return prelude + source.replace(target, () => workerPrefix + JSON.stringify(prelude) + ' + ' + worker + ';');
+}
+
+export function install(root = '/usr/local/lib/node_modules/@deepseek-ai/dsh') {
+  const plugin = join(root, 'node_modules/@deepseek-ai/dsh-client-ui-sidebar-documentpreview');
+  const version = JSON.parse(readFileSync(join(root, 'package.json'), 'utf8')).version;
+  const pluginVersion = JSON.parse(readFileSync(join(plugin, 'package.json'), 'utf8')).version;
+  const file = join(plugin, 'lib/client.pdf.js');
+  writeFileSync(file, patchPdfClient(readFileSync(file, 'utf8'), version, pluginVersion));
+}
+
+if (process.argv[1] && import.meta.url === pathToFileURL(resolve(process.argv[1])).href) install();