From 9bac2b8cdf153b1d8be3ec7507c5327edb32dc0f Mon Sep 17 00:00:00 2001
From: pi-agent <pi-agent@internal.local>
Date: Wed, 18 Mar 2026 19:23:42 +0800
Subject: [PATCH 1/3] fix: support empty string literals in textfx

- Fix tokenizer to emit empty string token when closing quote on empty buffer
- Add force parameter to flush_word() to handle empty quoted strings
- Add test case for echo "" and echo ''
---
 konabot/plugins/handle_text/base.py |  7 ++++---
 tests/test_textfx_shell.py          | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/konabot/plugins/handle_text/base.py b/konabot/plugins/handle_text/base.py
index b199ae3..d7da900 100644
--- a/konabot/plugins/handle_text/base.py
+++ b/konabot/plugins/handle_text/base.py
@@ -161,9 +161,9 @@ class PipelineRunner:
             "'": "'",
         }
 
-        def flush_word():
+        def flush_word(force: bool = False):
             nonlocal buf
-            if buf:
+            if buf or force:
                 tokens.append(Token(TokenKind.WORD, buf))
                 buf = ""
 
@@ -178,6 +178,7 @@ class PipelineRunner:
                     escape = True
                 elif c == quote:
                     quote = None
+                    flush_word(force=True)  # 引号闭合时强制 flush，即使是空字符串
                 else:
                     buf += c
                 i += 1
@@ -188,7 +189,7 @@ class PipelineRunner:
                 i += 1
                 continue
 
-            if c.isspace() or c in "  ":
+            if c.isspace() or c in "  ":
                 flush_word()
                 i += 1
                 continue
diff --git a/tests/test_textfx_shell.py b/tests/test_textfx_shell.py
index 5e7def7..10f0636 100644
--- a/tests/test_textfx_shell.py
+++ b/tests/test_textfx_shell.py
@@ -205,3 +205,21 @@ async def test_while_body_can_use_if(runner: PipelineRunner):
     assert not isinstance(parsed, str)
     results = await runner.run_pipeline(parsed, None, TextHandlerEnvironment(False))
     assert results[0].code == 1
+
+
+@pytest.mark.asyncio
+async def test_echo_empty_string(runner: PipelineRunner):
+    """测试 echo 空字符串"""
+    # 双引号空字符串
+    parsed = runner.parse_pipeline('echo ""')
+    assert not isinstance(parsed, str)
+    results = await runner.run_pipeline(parsed, None, TextHandlerEnvironment(False))
+    assert results[0].code == 0
+    assert results[0].ostream == ''
+    
+    # 单引号空字符串
+    parsed2 = runner.parse_pipeline("echo ''")
+    assert not isinstance(parsed2, str)
+    results2 = await runner.run_pipeline(parsed2, None, TextHandlerEnvironment(False))
+    assert results2[0].code == 0
+    assert results2[0].ostream == ''

From 717b7a95e80345e603c72f08e5272e52ec07b00e Mon Sep 17 00:00:00 2001
From: pi-agent <pi-agent@internal.local>
Date: Wed, 18 Mar 2026 19:30:55 +0800
Subject: [PATCH 2/3] fix: echo should not read stdin (Unix semantics)

---
 konabot/plugins/handle_text/handlers/unix_handlers.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/konabot/plugins/handle_text/handlers/unix_handlers.py b/konabot/plugins/handle_text/handlers/unix_handlers.py
index 16e210d..f9ab5e7 100644
--- a/konabot/plugins/handle_text/handlers/unix_handlers.py
+++ b/konabot/plugins/handle_text/handlers/unix_handlers.py
@@ -13,10 +13,9 @@ class THEcho(TextHandler):
     async def handle(
         self, env: TextHandlerEnvironment, istream: str | None, args: list[str]
     ) -> TextHandleResult:
-        if len(args) == 0 and istream is None:
+        # echo 不读 stdin，只输出参数（Unix 语义）
+        if len(args) == 0:
             return TextHandleResult(1, "请在 echo 后面添加需要输出的文本")
-        if istream is not None:
-            return TextHandleResult(0, "\n".join([istream] + args))
         return TextHandleResult(0, "\n".join(args))
 
 

From 5b1c6d446cdbb948443fff8b3dffdd3f6e2cc1c9 Mon Sep 17 00:00:00 2001
From: pi-agent <pi-agent@internal.local>
Date: Wed, 18 Mar 2026 19:40:02 +0800
Subject: [PATCH 3/3] fix: remove redundant whitespace check; echo no-arg
 outputs empty line

---
 konabot/plugins/handle_text/base.py                   | 2 +-
 konabot/plugins/handle_text/handlers/unix_handlers.py | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/konabot/plugins/handle_text/base.py b/konabot/plugins/handle_text/base.py
index d7da900..b9d23c3 100644
--- a/konabot/plugins/handle_text/base.py
+++ b/konabot/plugins/handle_text/base.py
@@ -189,7 +189,7 @@ class PipelineRunner:
                 i += 1
                 continue
 
-            if c.isspace() or c in "  ":
+            if c.isspace():
                 flush_word()
                 i += 1
                 continue
diff --git a/konabot/plugins/handle_text/handlers/unix_handlers.py b/konabot/plugins/handle_text/handlers/unix_handlers.py
index f9ab5e7..1434e15 100644
--- a/konabot/plugins/handle_text/handlers/unix_handlers.py
+++ b/konabot/plugins/handle_text/handlers/unix_handlers.py
@@ -14,8 +14,7 @@ class THEcho(TextHandler):
         self, env: TextHandlerEnvironment, istream: str | None, args: list[str]
     ) -> TextHandleResult:
         # echo 不读 stdin，只输出参数（Unix 语义）
-        if len(args) == 0:
-            return TextHandleResult(1, "请在 echo 后面添加需要输出的文本")
+        # 无参数时输出空行（与 Unix echo 行为一致）
         return TextHandleResult(0, "\n".join(args))