test: Phase 1 — 添加 8 个纯函数测试文件 (+134 tests)

- errors.test.ts: 28 tests (isAbortError, toError, errorMessage, getErrnoCode, isFsInaccessible, classifyAxiosError 等)
- shellRuleMatching.test.ts: 22 tests (permissionRuleExtractPrefix, hasWildcards, matchWildcardPattern, parsePermissionRule 等)
- argumentSubstitution.test.ts: 18 tests (parseArguments, parseArgumentNames, generateProgressiveArgumentHint, substituteArguments)
- CircularBuffer.test.ts: 12 tests (add, addAll, getRecent, toArray, clear, length)
- sanitization.test.ts: 14 tests (partiallySanitizeUnicode, recursivelySanitizeUnicode)
- slashCommandParsing.test.ts: 8 tests (parseSlashCommand)
- contentArray.test.ts: 6 tests (insertBlockAfterToolResults)
- objectGroupBy.test.ts: 5 tests (objectGroupBy)

总计：781 tests / 40 files

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/utils/__tests__/contentArray.test.ts

@@ -0,0 +1,55 @@
+import { describe, expect, test } from "bun:test";
+import { insertBlockAfterToolResults } from "../contentArray";
+
+describe("insertBlockAfterToolResults", () => {
+  test("inserts after last tool_result", () => {
+    const content: any[] = [
+      { type: "tool_result", content: "r1" },
+      { type: "text", text: "hello" },
+    ];
+    insertBlockAfterToolResults(content, { type: "text", text: "inserted" });
+    expect(content[1]).toEqual({ type: "text", text: "inserted" });
+    expect(content).toHaveLength(3);
+  });
+
+  test("inserts after last of multiple tool_results", () => {
+    const content: any[] = [
+      { type: "tool_result", content: "r1" },
+      { type: "tool_result", content: "r2" },
+      { type: "text", text: "end" },
+    ];
+    insertBlockAfterToolResults(content, { type: "text", text: "new" });
+    expect(content[2]).toEqual({ type: "text", text: "new" });
+  });
+
+  test("appends continuation when inserted block would be last", () => {
+    const content: any[] = [{ type: "tool_result", content: "r1" }];
+    insertBlockAfterToolResults(content, { type: "text", text: "new" });
+    expect(content).toHaveLength(3); // original + inserted + continuation
+    expect(content[2]).toEqual({ type: "text", text: "." });
+  });
+
+  test("inserts before last block when no tool_results", () => {
+    const content: any[] = [
+      { type: "text", text: "a" },
+      { type: "text", text: "b" },
+    ];
+    insertBlockAfterToolResults(content, { type: "text", text: "new" });
+    expect(content[1]).toEqual({ type: "text", text: "new" });
+    expect(content).toHaveLength(3);
+  });
+
+  test("handles empty array", () => {
+    const content: any[] = [];
+    insertBlockAfterToolResults(content, { type: "text", text: "new" });
+    expect(content).toHaveLength(1);
+    expect(content[0]).toEqual({ type: "text", text: "new" });
+  });
+
+  test("handles single element array with no tool_result", () => {
+    const content: any[] = [{ type: "text", text: "only" }];
+    insertBlockAfterToolResults(content, { type: "text", text: "new" });
+    expect(content[0]).toEqual({ type: "text", text: "new" });
+    expect(content[1]).toEqual({ type: "text", text: "only" });
+  });
+});