claude-code-chat-browser: Tool dispatch coordination - single authoritative KNOWN_TOOL_TYPES registry

CONTRIBUTING.md

@@ -100,6 +100,7 @@ npm run test:coverage   # optional
 | New `ErrorCode` | Parametrized row in `tests/test_error_codes.py` |
 | Search / limit validation | `tests/test_search.py` |
 | New `_parse_tool_result` dispatch entry | Fixture + assertion in `tests/test_jsonl_parser.py` |
+| New Claude Code tool use name | See **Adding a new tool type** below |
 | CLI behavior | `tests/test_cli_e2e.py` (subprocess) or `tests/test_cli_args.py` (parser only) |
 | Frontend shared module | `static/js/shared/*.test.js` (vitest) |
 | Error response shape | `tests/test_error_propagation.py` regression |
@@ -140,6 +141,17 @@ npm run test:coverage   # optional
 
 See [`docs/architecture.md`](docs/architecture.md) for data flow, export state machine, and component diagram.
 
+## Adding a new tool type
+
+Claude Code assistant `tool_use` blocks carry a `name` string (e.g. `"Read"`, `"Bash"`). The browser coordinates that name across four sites; drift is caught by `tests/test_tool_dispatch_sync.py`.
+
+1. **`utils/tool_dispatch.py`** — add the name to `_FILE_ACTIVITY_HANDLERS` (`None` if no file/bash/web side effects); `KNOWN_TOOL_TYPES` is derived from its keys. If the tool has a distinct `toolUseResult` JSON shape, add `(predicate, builder)` to `_TOOL_RESULT_DISPATCH` (respect ordering — see module docstring and `tests/test_tool_dispatch_ordering.py`).
+2. **`models/tool_results.py`** — add the name to `ToolNameLiteral` and, when the tool has a distinct result payload, add the TypedDict, type guard (`is_*_tool_result`), and union member on `ToolResultUnion`.
+3. **`utils/md_exporter.py`** — add an `elif name == "…"` branch in `_render_tool_use` (sync test parses these branches).
+4. **`static/js/render/registry.js`** — add a `TOOL_USE_RENDERERS` entry (and a `tool_use/*.js` renderer module).
+5. **Optional result UI** — if the backend emits a new `result_type`, add `TOOL_RESULT_RENDERERS` and a `tool_result/*.js` module.
+6. Run `pytest tests/test_tool_dispatch_sync.py -v` — failure names the site missing the new type.
+
 ## Getting help
 
 Open an issue with a clear repro or propose a draft PR early for CI feedback.

models/tool_results.py

@@ -220,6 +220,7 @@ def is_user_input_tool_result(tr: ToolResultDict) -> TypeGuard[UserInputToolResu
 
 # Tool names on assistant tool_use blocks — pairs with slug on user tool_result rows.
 ToolNameLiteral = Literal[
+    "AskUserQuestion",
     "Bash",
     "Read",
     "Write",

tests/test_tool_dispatch_sync.py

@@ -0,0 +1,112 @@
+"""Contract test: ``KNOWN_TOOL_TYPES`` must match all four dispatch sites.
+
+Sites (each compared to ``KNOWN_TOOL_TYPES`` in ``utils/tool_dispatch.py``):
+- ``utils/md_exporter.py`` — ``_render_tool_use`` if/elif branches (parsed)
+- ``models/tool_results.py`` — ``ToolNameLiteral``
+- ``static/js/render/registry.js`` — ``TOOL_USE_RENDERERS`` keys (parsed)
+"""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+from typing import get_args
+
+import pytest
+
+from models.tool_results import ToolNameLiteral
+from utils.tool_dispatch import KNOWN_TOOL_TYPES
+
+_REPO_ROOT = Path(__file__).resolve().parents[1]
+_FRONTEND_REGISTRY = _REPO_ROOT / "static" / "js" / "render" / "registry.js"
+_MD_EXPORTER = _REPO_ROOT / "utils" / "md_exporter.py"
+
+
+def _format_set_diff(expected: frozenset[str], actual: frozenset[str], site: str) -> str:
+    missing = sorted(expected - actual)
+    extra = sorted(actual - expected)
+    parts: list[str] = []
+    if missing:
+        parts.append(f"missing tool type(s) {missing!r} in {site}")
+    if extra:
+        parts.append(f"unexpected tool type(s) {extra!r} in {site}")
+    return "; ".join(parts)
+
+
+def _parse_frontend_tool_use_renderers(path: Path) -> frozenset[str]:
+    """Extract ``TOOL_USE_RENDERERS`` keys.
+
+    Assumes values are bare identifiers (``Bash: renderBashUse``). Brace-depth
+    parsing avoids truncating the object body if a value ever contains ``}``.
+    """
+    text = path.read_text(encoding="utf-8")
+    marker = "export const TOOL_USE_RENDERERS = {"
+    start = text.find(marker)
+    if start == -1:
+        msg = f"Could not find TOOL_USE_RENDERERS in {path}"
+        raise ValueError(msg)
+    i = start + len(marker)
+    depth = 1
+    body_start = i
+    while i < len(text) and depth > 0:
+        ch = text[i]
+        if ch == "{":
+            depth += 1
+        elif ch == "}":
+            depth -= 1
+        i += 1
+    if depth != 0:
+        msg = f"Unbalanced braces in TOOL_USE_RENDERERS in {path}"
+        raise ValueError(msg)
+    body = text[body_start : i - 1]
+    keys = re.findall(r"^\s*(\w+)\s*:", body, re.MULTILINE)
+    return frozenset(keys)
+
+
+def _parse_md_exporter_tool_use_handlers(path: Path) -> frozenset[str]:
+    """Extract tool names handled by ``_render_tool_use`` if/elif branches."""
+    text = path.read_text(encoding="utf-8")
+    match = re.search(
+        r"def _render_tool_use\(.*?(?=\ndef _render_tool_result)",
+        text,
+        re.DOTALL,
+    )
+    if not match:
+        msg = f"Could not find _render_tool_use in {path}"
+        raise ValueError(msg)
+    body = match.group(0)
+    names = set(re.findall(r'(?:if|elif) name == "([^"]+)"', body))
+    for tuple_match in re.finditer(r"elif name in \(([^)]+)\)", body):
+        names.update(re.findall(r'"([^"]+)"', tuple_match.group(1)))
+    return frozenset(names)
+
+
+def test_md_exporter_handlers_match_known_tool_types() -> None:
+    site = "utils/md_exporter.py (_render_tool_use branches)"
+    try:
+        actual = _parse_md_exporter_tool_use_handlers(_MD_EXPORTER)
+    except ValueError as exc:
+        pytest.fail(f"{site}: {exc}")
+    if actual != KNOWN_TOOL_TYPES:
+        pytest.fail(_format_set_diff(KNOWN_TOOL_TYPES, actual, site))
+
+
+def test_tool_name_literal_matches_known_tool_types() -> None:
+    site = "models/tool_results.py (ToolNameLiteral)"
+    actual = frozenset(get_args(ToolNameLiteral))
+    if actual != KNOWN_TOOL_TYPES:
+        pytest.fail(_format_set_diff(KNOWN_TOOL_TYPES, actual, site))
+
+
+def test_frontend_registry_matches_known_tool_types() -> None:
+    site = "static/js/render/registry.js (TOOL_USE_RENDERERS)"
+    try:
+        actual = _parse_frontend_tool_use_renderers(_FRONTEND_REGISTRY)
+    except ValueError as exc:
+        pytest.fail(f"{site}: {exc}")
+    if actual != KNOWN_TOOL_TYPES:
+        pytest.fail(_format_set_diff(KNOWN_TOOL_TYPES, actual, site))
+
+
+def test_known_tool_types_nonempty() -> None:
+    assert KNOWN_TOOL_TYPES

utils/jsonl_parser.py

@@ -19,7 +19,7 @@
     normalize_content as _normalize_content,
 )
 from utils.session_peek import quick_session_info
-from utils.tool_dispatch import _parse_tool_result
+from utils.tool_dispatch import _parse_tool_result, track_tool_file_activity
 from utils.validation import validate_session_dict
 
 __all__ = ["parse_session", "quick_session_info"]
@@ -311,7 +311,7 @@ def _process_assistant(
             if isinstance(tool_id, str):
                 tool_use["id"] = tool_id
             tool_uses.append(tool_use)
-            _track_file_activity(tool_name, safe_input, metadata)
+            track_tool_file_activity(tool_name, safe_input, metadata)
 
     messages.append(
         {
@@ -388,26 +388,3 @@ def _process_progress(entry: dict[str, Any], messages: list[MessageDict]) -> Non
             "is_sidechain": entry.get("isSidechain", False),
         }
     )
-
-
-def _track_file_activity(
-    tool_name: str, tool_input: dict[str, Any], metadata: dict[str, Any]
-) -> None:
-    """Look at what each tool call did and record which files got touched,
-    what commands got run, what URLs got fetched."""
-    raw_fp = tool_input.get("file_path", "")
-    fp = raw_fp if isinstance(raw_fp, str) else ""
-    if tool_name == "Read" and fp:
-        metadata["files_read"].add(fp)
-    elif tool_name == "Write" and fp:
-        metadata["files_created"].add(fp)
-    elif tool_name == "Edit" and fp:
-        metadata["files_written"].add(fp)
-    elif tool_name == "Bash":
-        cmd = tool_input.get("command", "")
-        if isinstance(cmd, str) and cmd:
-            metadata["bash_commands"].append(cmd)
-    elif tool_name in ("WebFetch", "WebSearch"):
-        url_or_query = tool_input.get("url") or tool_input.get("query", "")
-        if isinstance(url_or_query, str) and url_or_query:
-            metadata["web_fetches"].append(url_or_query)

utils/md_exporter.py

@@ -323,7 +323,7 @@ def _render_tool_use(tool: ToolUseDict) -> str:
                     continue
                 lines.append(f">\n> Q: {q.get('question', '')}")
     else:
-        lines.append(f">\n> Input: `{str(inp)}`")
+        lines.append(f">\n> Input (unknown tool type): `{str(inp)}`")
 
     return "\n".join(lines)
 

utils/tool_dispatch.py

@@ -15,9 +15,25 @@
 tuple there when a new predicate must sit above another.
 
 Predicates live in ``models.tool_results`` (single source of truth for narrowing).
+
+Adding a new Claude Code **tool use** name (e.g. ``"Read"``, ``"Bash"``):
+
+1. Add the name to ``_FILE_ACTIVITY_HANDLERS`` below (``None`` if no file/bash/web
+   side effects); ``KNOWN_TOOL_TYPES`` is derived from its keys.
+2. Add the name to ``ToolNameLiteral`` in ``models/tool_results.py`` and, if the
+   tool has a distinct ``toolUseResult`` JSON shape, add the TypedDict, predicate,
+   and ``(predicate, builder)`` pair in ``_TOOL_RESULT_DISPATCH`` (respect ordering
+   — see notes above and ``tests/test_tool_dispatch_ordering.py``).
+3. Add a Markdown branch in ``utils/md_exporter.py`` ``_render_tool_use``.
+4. Add ``TOOL_USE_RENDERERS`` entry in ``static/js/render/registry.js``.
+5. Run ``pytest tests/test_tool_dispatch_sync.py -v`` — it fails with the
+   missing site if any step was skipped.
+
+See ``CONTRIBUTING.md`` § "Adding a new tool type".
 """
 
-from typing import cast
+from collections.abc import Callable
+from typing import Any, cast
 
 from models.tool_results import (
     ToolResultDict,
@@ -219,6 +235,70 @@ def _tool_result_build_user_input(tr: ToolResultDict, base: dict[str, object]) -
     (is_user_input_tool_result, _tool_result_build_user_input),
 )
 
+# Claude Code assistant tool_use ``name`` values coordinated across parser file
+# activity, Markdown export, and the SPA ``TOOL_USE_RENDERERS`` map.
+# ``_FILE_ACTIVITY_HANDLERS`` is the single registry; ``KNOWN_TOOL_TYPES`` is derived.
+
+
+def _file_activity_read(tool_input: dict[str, Any], metadata: dict[str, Any]) -> None:
+    raw_fp = tool_input.get("file_path", "")
+    fp = raw_fp if isinstance(raw_fp, str) else ""
+    if fp:
+        metadata["files_read"].add(fp)
+
+
+def _file_activity_write(tool_input: dict[str, Any], metadata: dict[str, Any]) -> None:
+    raw_fp = tool_input.get("file_path", "")
+    fp = raw_fp if isinstance(raw_fp, str) else ""
+    if fp:
+        metadata["files_created"].add(fp)
+
+
+def _file_activity_edit(tool_input: dict[str, Any], metadata: dict[str, Any]) -> None:
+    raw_fp = tool_input.get("file_path", "")
+    fp = raw_fp if isinstance(raw_fp, str) else ""
+    if fp:
+        metadata["files_written"].add(fp)
+
+
+def _file_activity_bash(tool_input: dict[str, Any], metadata: dict[str, Any]) -> None:
+    cmd = tool_input.get("command", "")
+    if isinstance(cmd, str) and cmd:
+        metadata["bash_commands"].append(cmd)
+
+
+def _file_activity_web(tool_input: dict[str, Any], metadata: dict[str, Any]) -> None:
+    url_or_query = tool_input.get("url") or tool_input.get("query", "")
+    if isinstance(url_or_query, str) and url_or_query:
+        metadata["web_fetches"].append(url_or_query)
+
+
+_FILE_ACTIVITY_HANDLERS: dict[str, Callable[[dict[str, Any], dict[str, Any]], None] | None] = {
+    "AskUserQuestion": None,
+    "Bash": _file_activity_bash,
+    "Edit": _file_activity_edit,
+    "Glob": None,
+    "Grep": None,
+    "Read": _file_activity_read,
+    "Task": None,
+    "TodoWrite": None,
+    "WebFetch": _file_activity_web,
+    "WebSearch": _file_activity_web,
+    "Write": _file_activity_write,
+}
+KNOWN_TOOL_TYPES: frozenset[str] = frozenset(_FILE_ACTIVITY_HANDLERS)
+
+
+def track_tool_file_activity(
+    tool_name: str, tool_input: dict[str, Any], metadata: dict[str, Any]
+) -> None:
+    """Record file/bash/web side effects for tools listed in ``KNOWN_TOOL_TYPES``."""
+    if tool_name not in KNOWN_TOOL_TYPES:
+        return
+    handler = _FILE_ACTIVITY_HANDLERS[tool_name]
+    if handler is not None:
+        handler(tool_input, metadata)
+
 
 def _parse_tool_result(
     tool_result: ToolResultUnion | None, slug: str | None = None