feat(config-editor): TsConfigFile load/read/patch/add/delete/save (entry-level AST patch, .bak + syntax check)

26 IO tests green: serializer, parser (speed/enumRef/raw), TsConfigFile
round-trip (load/patch/add/delete/save preserving symbolic expressions).

extensions/pixelhero-config-editor/src/io/TsConfigFile.ts

@@ -0,0 +1,110 @@
+import * as fs from 'node:fs';
+import * as ts from 'typescript';
+import { RecordValue } from './recordValue';
+import { findExportObjectLiteral, parseExpression } from './parser';
+import { serializeEntry } from './serializer';
+
+/**
+ * 以"条目级 AST 区间替换"方式读写一个 `export const <name>: Record<number,X> = {...}` 配置文件。
+ * 保留符号表达式（speed）与枚举引用（enumRef），未识别表达式原样保留（raw）。
+ * save() 纯逻辑：仅做 fs 读写 + 语法校验（写 .bak）；asset-db 刷新由主进程在 save 成功后调用。
+ */
+export class TsConfigFile {
+  private sourceText = '';
+  private sourceFile!: ts.SourceFile;
+  private targetNode!: ts.ObjectLiteralExpression;
+  private dirty = false;
+
+  constructor(public readonly filePath: string, public readonly exportName: string) {}
+
+  load(): void {
+    this.sourceText = fs.readFileSync(this.filePath, 'utf8');
+    this.reparse();
+    this.dirty = false;
+  }
+
+  private reparse(): void {
+    // 第 4 参数 setParentNodes 必须为 true，否则 node.getStart()/getEnd() 不可用。
+    this.sourceFile = ts.createSourceFile(this.filePath, this.sourceText, ts.ScriptTarget.Latest, true);
+    const node = findExportObjectLiteral(this.sourceFile, this.exportName);
+    if (!node) throw new Error(`export const ${this.exportName} not found or not an object literal in ${this.filePath}`);
+    this.targetNode = node;
+  }
+
+  getKeys(): string[] {
+    return this.targetNode.properties.map(p => (p.name as ts.PropertyName).getText());
+  }
+
+  read(key: string): RecordValue | null {
+    const entry = this.findEntry(key);
+    if (!entry) return null;
+    return parseExpression(entry.initializer);
+  }
+
+  private findEntry(key: string): ts.PropertyAssignment | undefined {
+    return this.targetNode.properties.find(p => (p.name as ts.PropertyName).getText() === key) as ts.PropertyAssignment | undefined;
+  }
+
+  getText(): string { return this.sourceText; }
+  isDirty(): boolean { return this.dirty; }
+
+  patch(key: string, value: RecordValue): void {
+    const entry = this.findEntry(key);
+    const newText = serializeEntry(key, value);
+    if (entry) {
+      const { start, end } = this.entrySpan(entry);
+      this.sourceText = this.sourceText.slice(0, start) + newText + this.sourceText.slice(end);
+    } else {
+      this.insertEntry(newText);
+    }
+    this.reparse();
+    this.dirty = true;
+  }
+
+  add(key: string, value: RecordValue): void {
+    if (this.findEntry(key)) throw new Error(`key ${key} already exists`);
+    this.insertEntry(serializeEntry(key, value));
+    this.reparse();
+    this.dirty = true;
+  }
+
+  delete(key: string): void {
+    const entry = this.findEntry(key);
+    if (!entry) return;
+    const { start, end } = this.entrySpan(entry);
+    this.sourceText = this.sourceText.slice(0, start) + this.sourceText.slice(end);
+    this.reparse();
+    this.dirty = true;
+  }
+
+  save(): { ok: true } | { ok: false; error: string } {
+    if (!this.dirty) return { ok: true };
+    const check = ts.createSourceFile(this.filePath, this.sourceText, ts.ScriptTarget.Latest, true);
+    if (check.parseDiagnostics.length > 0) {
+      const msg = check.parseDiagnostics.map(d => ts.flattenDiagnosticMessageText(d.messageText, '\n')).join('; ');
+      return { ok: false, error: `syntax error after edit: ${msg}` };
+    }
+    // .bak 取自磁盘原始内容（落盘前的当前文件），保证可回滚。
+    fs.writeFileSync(this.filePath + '.bak', fs.readFileSync(this.filePath));
+    fs.writeFileSync(this.filePath, this.sourceText);
+    this.dirty = false;
+    return { ok: true };
+  }
+
+  /** 条目文本区间：从 key 词法起始（不含前导缩进 trivia，避免吞掉上一行换行）到尾随逗号止。 */
+  private entrySpan(entry: ts.PropertyAssignment): { start: number; end: number } {
+    const start = entry.getStart();
+    let end = entry.getEnd();
+    const comma = /^\s*,/.exec(this.sourceText.slice(end));
+    if (comma) end += comma[0].length;
+    return { start, end };
+  }
+
+  /** 在闭合 `}` 前追加一条新记录（4 空格缩进）。 */
+  private insertEntry(entryText: string): void {
+    const closeBrace = this.targetNode.getLastToken();
+    if (!closeBrace) throw new Error('object literal has no closing brace');
+    const pos = closeBrace.getStart();
+    this.sourceText = this.sourceText.slice(0, pos) + `    ${entryText}\n    ` + this.sourceText.slice(pos);
+  }
+}