fix: harden PR body validator for mixed escaped-newline and tea path (#392)

scripts/validate_pr_body.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 
 import argparse
 import json
+import shutil
 import re
 import subprocess
 import sys
@@ -12,11 +13,31 @@ from pathlib import Path
 
 HEADER_PATTERN = re.compile(r"^##\s+\S+", re.MULTILINE)
 LIST_ITEM_PATTERN = re.compile(r"^\s*(?:-|\*|\d+\.)\s+\S+", re.MULTILINE)
+FENCED_CODE_PATTERN = re.compile(r"```.*?```", re.DOTALL)
+INLINE_CODE_PATTERN = re.compile(r"`[^`]*`")
+
+
+def _strip_code_segments(text: str) -> str:
+    without_fences = FENCED_CODE_PATTERN.sub("", text)
+    return INLINE_CODE_PATTERN.sub("", without_fences)
+
+
+def resolve_tea_binary() -> str:
+    tea_from_path = shutil.which("tea")
+    if tea_from_path:
+        return tea_from_path
+
+    tea_home = Path.home() / "bin" / "tea"
+    if tea_home.exists():
+        return str(tea_home)
+
+    raise RuntimeError("tea binary not found (checked PATH and ~/bin/tea)")
 
 
 def validate_pr_body_text(text: str) -> list[str]:
     errors: list[str] = []
-    if "\\n" in text and "\n" not in text:
+    searchable = _strip_code_segments(text)
+    if "\\n" in searchable:
         errors.append("body contains escaped newline sequence (\\n)")
     if text.count("```") % 2 != 0:
         errors.append("body has unbalanced fenced code blocks (``` count is odd)")
@@ -28,10 +49,11 @@ def validate_pr_body_text(text: str) -> list[str]:
 
 
 def fetch_pr_body(pr_number: int) -> str:
+    tea_binary = resolve_tea_binary()
     try:
         completed = subprocess.run(
             [
-                "tea",
+                tea_binary,
                 "api",
                 "-R",
                 "origin",

tests/test_validate_pr_body.py

@@ -24,9 +24,24 @@ def test_validate_pr_body_text_detects_escaped_newline() -> None:
     assert any("escaped newline" in err for err in errors)
 
 
-def test_validate_pr_body_text_allows_literal_sequence_when_multiline() -> None:
+def test_validate_pr_body_text_detects_escaped_newline_in_multiline_body() -> None:
     module = _load_module()
-    text = "## Summary\n- escaped sequence example: \\\\n"
+    text = "## Summary\n- first line\n- broken line with \\n literal"
+    errors = module.validate_pr_body_text(text)
+    assert any("escaped newline" in err for err in errors)
+
+
+def test_validate_pr_body_text_allows_escaped_newline_in_code_blocks() -> None:
+    module = _load_module()
+    text = "\n".join(
+        [
+            "## Summary",
+            "- example uses `\\n` for explanation",
+            "```bash",
+            "printf 'line1\\nline2\\n'",
+            "```",
+        ]
+    )
     assert module.validate_pr_body_text(text) == []
 
 
@@ -63,12 +78,13 @@ def test_fetch_pr_body_reads_body_from_tea_api(monkeypatch) -> None:
     module = _load_module()
 
     def fake_run(cmd, check, capture_output, text):  # noqa: ANN001
-        assert "tea" in cmd[0]
+        assert cmd[0] == "/tmp/tea-bin"
         assert check is True
         assert capture_output is True
         assert text is True
         return SimpleNamespace(stdout=json.dumps({"body": "## Summary\n- item"}))
 
+    monkeypatch.setattr(module, "resolve_tea_binary", lambda: "/tmp/tea-bin")
     monkeypatch.setattr(module.subprocess, "run", fake_run)
     assert module.fetch_pr_body(391) == "## Summary\n- item"
 
@@ -79,6 +95,18 @@ def test_fetch_pr_body_rejects_non_string_body(monkeypatch) -> None:
     def fake_run(cmd, check, capture_output, text):  # noqa: ANN001
         return SimpleNamespace(stdout=json.dumps({"body": 123}))
 
+    monkeypatch.setattr(module, "resolve_tea_binary", lambda: "/tmp/tea-bin")
     monkeypatch.setattr(module.subprocess, "run", fake_run)
     with pytest.raises(RuntimeError):
         module.fetch_pr_body(391)
+
+
+def test_resolve_tea_binary_falls_back_to_home_bin(monkeypatch, tmp_path) -> None:
+    module = _load_module()
+    tea_home = tmp_path / "bin" / "tea"
+    tea_home.parent.mkdir(parents=True)
+    tea_home.write_text("#!/usr/bin/env bash\n", encoding="utf-8")
+
+    monkeypatch.setattr(module.shutil, "which", lambda _: None)
+    monkeypatch.setattr(module.Path, "home", lambda: tmp_path)
+    assert module.resolve_tea_binary() == str(tea_home)