feat: 优化 parse_post_content 函数，支持处理包含内容数组的代码块，并添加相关单元测试以确保向后兼容性

src/channels/feishu.rs

@@ -1384,7 +1384,16 @@ fn parse_post_content(content: &str) -> String {
             }
             "code_block" => {
                 let lang = el.get("language").and_then(|l| l.as_str()).unwrap_or("");
-                let code_text = el.get("text").and_then(|t| t.as_str()).unwrap_or("");
+                let code_text = if let Some(content_arr) = el.get("content").and_then(|c| c.as_array()) {
+                    content_arr
+                        .iter()
+                        .filter_map(|item| item.get("text").and_then(|t| t.as_str()))
+                        .collect::<Vec<_>>()
+                        .join("")
+                } else {
+                    // Fallback to text field for backwards compatibility
+                    el.get("text").and_then(|t| t.as_str()).unwrap_or("").to_string()
+                };
                 out.push(format!("\n```{}\n{}\n```\n", lang, code_text));
             }
             _ => {
@@ -2190,7 +2199,7 @@ fn sanitize_download_file_name(file_name: &str) -> String {
 mod tests {
     use super::{
         FeishuChannel, MsgFormat, extract_file_name_from_content_disposition,
-        infer_download_filename, sanitize_download_file_name,
+        infer_download_filename, parse_post_content, sanitize_download_file_name,
     };
 
     #[test]
@@ -2279,6 +2288,42 @@ mod tests {
         let file_name = extract_file_name_from_content_disposition(&headers);
         assert_eq!(file_name.as_deref(), Some("archive.zip"));
     }
+
+    #[test]
+    fn parse_post_content_handles_code_block_with_content_array() {
+        // Test parsing code_block with content array (standard Feishu format)
+        let post_json = r#"{"post":{"zh_cn":{"content":[[{"tag":"code_block","language":"python","content":[{"tag":"text","text":"def hello():"},{"tag":"text","text":"    print('world')"}]}]]}}}"#;
+        let result = parse_post_content(post_json);
+        assert!(result.contains("```python"));
+        assert!(result.contains("def hello():"));
+        assert!(result.contains("print('world')"));
+    }
+
+    #[test]
+    fn parse_post_content_handles_code_block_with_fallback_text() {
+        // Backwards compatibility: some formats might use text field directly
+        let post_json = r#"{"post":{"zh_cn":{"content":[[{"tag":"code_block","language":"rust","text":"fn main() {}"}]]}}}"#;
+        let result = parse_post_content(post_json);
+        assert!(result.contains("```rust"));
+        assert!(result.contains("fn main() {}"));
+    }
+
+    #[test]
+    fn parse_post_content_handles_code_block_without_language() {
+        // Test code_block without language field
+        let post_json = r#"{"post":{"zh_cn":{"content":[[{"tag":"code_block","content":[{"tag":"text","text":"plain text"}]}]]}}}"#;
+        let result = parse_post_content(post_json);
+        assert!(result.contains("```"));
+        assert!(result.contains("plain text"));
+    }
+
+    #[test]
+    fn parse_post_content_handles_empty_code_block() {
+        // Test code_block with empty content
+        let post_json = r#"{"post":{"zh_cn":{"content":[[{"tag":"code_block","language":"go"}]]}}}"#;
+        let result = parse_post_content(post_json);
+        assert!(result.contains("```go"));
+    }
 }
 
 #[async_trait]